From 41ab999c80f1d368f32a2554ba8f44feff26f54d Mon Sep 17 00:00:00 2001 From: Kent Yoder Date: Thu, 7 Jun 2012 13:47:14 -0500 Subject: tpm: Move tpm_get_random api into the TPM device driver Move the tpm_get_random api from the trusted keys code into the TPM device driver itself so that other callers can make use of it. Also, change the api slightly so that the number of bytes read is returned in the call, since the TPM command can potentially return fewer bytes than requested. Acked-by: David Safford Reviewed-by: H. Peter Anvin Signed-off-by: Kent Yoder --- security/keys/trusted.c | 54 +++++++++++-------------------------------------- 1 file changed, 12 insertions(+), 42 deletions(-) (limited to 'security') diff --git a/security/keys/trusted.c b/security/keys/trusted.c index 2d5d041f2049..3f163d0489ad 100644 --- a/security/keys/trusted.c +++ b/security/keys/trusted.c @@ -368,38 +368,6 @@ static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd, return rc; } -/* - * get a random value from TPM - */ -static int tpm_get_random(struct tpm_buf *tb, unsigned char *buf, uint32_t len) -{ - int ret; - - INIT_BUF(tb); - store16(tb, TPM_TAG_RQU_COMMAND); - store32(tb, TPM_GETRANDOM_SIZE); - store32(tb, TPM_ORD_GETRANDOM); - store32(tb, len); - ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data); - if (!ret) - memcpy(buf, tb->data + TPM_GETRANDOM_SIZE, len); - return ret; -} - -static int my_get_random(unsigned char *buf, int len) -{ - struct tpm_buf *tb; - int ret; - - tb = kmalloc(sizeof *tb, GFP_KERNEL); - if (!tb) - return -ENOMEM; - ret = tpm_get_random(tb, buf, len); - - kfree(tb); - return ret; -} - /* * Lock a trusted key, by extending a selected PCR. * @@ -413,8 +381,8 @@ static int pcrlock(const int pcrnum) if (!capable(CAP_SYS_ADMIN)) return -EPERM; - ret = my_get_random(hash, SHA1_DIGEST_SIZE); - if (ret < 0) + ret = tpm_get_random(TPM_ANY_NUM, hash, SHA1_DIGEST_SIZE); + if (ret != SHA1_DIGEST_SIZE) return ret; return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0; } @@ -429,8 +397,8 @@ static int osap(struct tpm_buf *tb, struct osapsess *s, unsigned char ononce[TPM_NONCE_SIZE]; int ret; - ret = tpm_get_random(tb, ononce, TPM_NONCE_SIZE); - if (ret < 0) + ret = tpm_get_random(TPM_ANY_NUM, ononce, TPM_NONCE_SIZE); + if (ret != TPM_NONCE_SIZE) return ret; INIT_BUF(tb); @@ -524,8 +492,8 @@ static int tpm_seal(struct tpm_buf *tb, uint16_t keytype, if (ret < 0) goto out; - ret = tpm_get_random(tb, td->nonceodd, TPM_NONCE_SIZE); - if (ret < 0) + ret = tpm_get_random(TPM_ANY_NUM, td->nonceodd, TPM_NONCE_SIZE); + if (ret != TPM_NONCE_SIZE) goto out; ordinal = htonl(TPM_ORD_SEAL); datsize = htonl(datalen); @@ -634,8 +602,8 @@ static int tpm_unseal(struct tpm_buf *tb, ordinal = htonl(TPM_ORD_UNSEAL); keyhndl = htonl(SRKHANDLE); - ret = tpm_get_random(tb, nonceodd, TPM_NONCE_SIZE); - if (ret < 0) { + ret = tpm_get_random(TPM_ANY_NUM, nonceodd, TPM_NONCE_SIZE); + if (ret != TPM_NONCE_SIZE) { pr_info("trusted_key: tpm_get_random failed (%d)\n", ret); return ret; } @@ -935,6 +903,7 @@ static int trusted_instantiate(struct key *key, const void *data, char *datablob; int ret = 0; int key_cmd; + size_t key_len; if (datalen <= 0 || datalen > 32767 || !data) return -EINVAL; @@ -974,8 +943,9 @@ static int trusted_instantiate(struct key *key, const void *data, pr_info("trusted_key: key_unseal failed (%d)\n", ret); break; case Opt_new: - ret = my_get_random(payload->key, payload->key_len); - if (ret < 0) { + key_len = payload->key_len; + ret = tpm_get_random(TPM_ANY_NUM, payload->key, key_len); + if (ret != key_len) { pr_info("trusted_key: key_create failed (%d)\n", ret); goto out; } -- cgit v1.2.3 From 20328b56cdf8fcc79f28c6c50ad8190fc0779e80 Mon Sep 17 00:00:00 2001 From: Kent Yoder Date: Wed, 22 Aug 2012 15:01:47 -0500 Subject: ima: enable the IBM vTPM as the default TPM in the PPC64 case Enable tpm_ibmvtpm driver by default when IMA is enabled on PPC64 Signed-off-by: Kent Yoder --- security/integrity/ima/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'security') diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index b9c1219924f1..809ccf19d09c 100644 --- a/security/integrity/ima/Kconfig +++ b/security/integrity/ima/Kconfig @@ -11,6 +11,7 @@ config IMA select CRYPTO_SHA1 select TCG_TPM if HAS_IOMEM && !UML select TCG_TIS if TCG_TPM && X86 + select TCG_IBMVTPM if TCG_TPM && PPC64 help The Trusted Computing Group(TCG) runtime Integrity Measurement Architecture(IMA) maintains a list of hash -- cgit v1.2.3 From c6993e4ac002c92bc75379212e9179c36d4bf7ee Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 4 Sep 2012 13:32:13 -0700 Subject: security: allow Yama to be unconditionally stacked Unconditionally call Yama when CONFIG_SECURITY_YAMA_STACKED is selected, no matter what LSM module is primary. Ubuntu and Chrome OS already carry patches to do this, and Fedora has voiced interest in doing this as well. Instead of having multiple distributions (or LSM authors) carrying these patches, just allow Yama to be called unconditionally when selected by the new CONFIG. Signed-off-by: Kees Cook Acked-by: Serge E. Hallyn Acked-by: Eric Paris Acked-by: John Johansen Signed-off-by: James Morris --- include/linux/security.h | 31 +++++++++++++++++++++++++++++++ security/security.c | 21 +++++++++++++++++++++ security/yama/Kconfig | 8 ++++++++ security/yama/yama_lsm.c | 14 ++++++++++---- 4 files changed, 70 insertions(+), 4 deletions(-) (limited to 'security') diff --git a/include/linux/security.h b/include/linux/security.h index 3dea6a9d568f..01ef030b9409 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -3021,5 +3021,36 @@ static inline void free_secdata(void *secdata) { } #endif /* CONFIG_SECURITY */ +#ifdef CONFIG_SECURITY_YAMA +extern int yama_ptrace_access_check(struct task_struct *child, + unsigned int mode); +extern int yama_ptrace_traceme(struct task_struct *parent); +extern void yama_task_free(struct task_struct *task); +extern int yama_task_prctl(int option, unsigned long arg2, unsigned long arg3, + unsigned long arg4, unsigned long arg5); +#else +static inline int yama_ptrace_access_check(struct task_struct *child, + unsigned int mode) +{ + return 0; +} + +static inline int yama_ptrace_traceme(struct task_struct *parent) +{ + return 0; +} + +static inline void yama_task_free(struct task_struct *task) +{ +} + +static inline int yama_task_prctl(int option, unsigned long arg2, + unsigned long arg3, unsigned long arg4, + unsigned long arg5) +{ + return -ENOSYS; +} +#endif /* CONFIG_SECURITY_YAMA */ + #endif /* ! __LINUX_SECURITY_H */ diff --git a/security/security.c b/security/security.c index 860aeb349cb3..68c1b9b45d93 100644 --- a/security/security.c +++ b/security/security.c @@ -136,11 +136,23 @@ int __init register_security(struct security_operations *ops) int security_ptrace_access_check(struct task_struct *child, unsigned int mode) { +#ifdef CONFIG_SECURITY_YAMA_STACKED + int rc; + rc = yama_ptrace_access_check(child, mode); + if (rc) + return rc; +#endif return security_ops->ptrace_access_check(child, mode); } int security_ptrace_traceme(struct task_struct *parent) { +#ifdef CONFIG_SECURITY_YAMA_STACKED + int rc; + rc = yama_ptrace_traceme(parent); + if (rc) + return rc; +#endif return security_ops->ptrace_traceme(parent); } @@ -761,6 +773,9 @@ int security_task_create(unsigned long clone_flags) void security_task_free(struct task_struct *task) { +#ifdef CONFIG_SECURITY_YAMA_STACKED + yama_task_free(task); +#endif security_ops->task_free(task); } @@ -876,6 +891,12 @@ int security_task_wait(struct task_struct *p) int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) { +#ifdef CONFIG_SECURITY_YAMA_STACKED + int rc; + rc = yama_task_prctl(option, arg2, arg3, arg4, arg5); + if (rc != -ENOSYS) + return rc; +#endif return security_ops->task_prctl(option, arg2, arg3, arg4, arg5); } diff --git a/security/yama/Kconfig b/security/yama/Kconfig index 51d6709d8bbd..20ef5143c0c0 100644 --- a/security/yama/Kconfig +++ b/security/yama/Kconfig @@ -11,3 +11,11 @@ config SECURITY_YAMA Further information can be found in Documentation/security/Yama.txt. If you are unsure how to answer this question, answer N. + +config SECURITY_YAMA_STACKED + bool "Yama stacked with other LSMs" + depends on SECURITY_YAMA + default n + help + When Yama is built into the kernel, force it to stack with the + selected primary LSM. diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c index d51b7c76c37d..9ca43c1ea630 100644 --- a/security/yama/yama_lsm.c +++ b/security/yama/yama_lsm.c @@ -100,7 +100,7 @@ static void yama_ptracer_del(struct task_struct *tracer, * yama_task_free - check for task_pid to remove from exception list * @task: task being removed */ -static void yama_task_free(struct task_struct *task) +void yama_task_free(struct task_struct *task) { yama_ptracer_del(task, task); } @@ -116,7 +116,7 @@ static void yama_task_free(struct task_struct *task) * Return 0 on success, -ve on error. -ENOSYS is returned when Yama * does not handle the given option. */ -static int yama_task_prctl(int option, unsigned long arg2, unsigned long arg3, +int yama_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) { int rc; @@ -243,7 +243,7 @@ static int ptracer_exception_found(struct task_struct *tracer, * * Returns 0 if following the ptrace is allowed, -ve on error. */ -static int yama_ptrace_access_check(struct task_struct *child, +int yama_ptrace_access_check(struct task_struct *child, unsigned int mode) { int rc; @@ -296,7 +296,7 @@ static int yama_ptrace_access_check(struct task_struct *child, * * Returns 0 if following the ptrace is allowed, -ve on error. */ -static int yama_ptrace_traceme(struct task_struct *parent) +int yama_ptrace_traceme(struct task_struct *parent) { int rc; @@ -330,6 +330,7 @@ static int yama_ptrace_traceme(struct task_struct *parent) return rc; } +#ifndef CONFIG_SECURITY_YAMA_STACKED static struct security_operations yama_ops = { .name = "yama", @@ -338,6 +339,7 @@ static struct security_operations yama_ops = { .task_prctl = yama_task_prctl, .task_free = yama_task_free, }; +#endif #ifdef CONFIG_SYSCTL static int yama_dointvec_minmax(struct ctl_table *table, int write, @@ -384,13 +386,17 @@ static struct ctl_table yama_sysctl_table[] = { static __init int yama_init(void) { +#ifndef CONFIG_SECURITY_YAMA_STACKED if (!security_module_enable(&yama_ops)) return 0; +#endif printk(KERN_INFO "Yama: becoming mindful.\n"); +#ifndef CONFIG_SECURITY_YAMA_STACKED if (register_security(&yama_ops)) panic("Yama: kernel registration failed.\n"); +#endif #ifdef CONFIG_SYSCTL if (!register_sysctl_paths(yama_sysctl_path, yama_sysctl_table)) -- cgit v1.2.3 From 2e4930eb7c8fb20a39dfb5f8a8f80402710dcea8 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 27 Aug 2012 11:38:13 -0700 Subject: Yama: handle 32-bit userspace prctl When running a 64-bit kernel and receiving prctls from a 32-bit userspace, the "-1" used as an unsigned long will end up being misdetected. The kernel is looking for 0xffffffffffffffff instead of 0xffffffff. Since prctl lacks a distinct compat interface, Yama needs to handle this translation itself. As such, support either value as meaning PR_SET_PTRACER_ANY, to avoid breaking the ABI for 64-bit. Signed-off-by: Kees Cook Acked-by: John Johansen Cc: stable@vger.kernel.org Signed-off-by: James Morris --- security/yama/yama_lsm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'security') diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c index 9ca43c1ea630..01d3b44b62c1 100644 --- a/security/yama/yama_lsm.c +++ b/security/yama/yama_lsm.c @@ -143,7 +143,7 @@ int yama_task_prctl(int option, unsigned long arg2, unsigned long arg3, if (arg2 == 0) { yama_ptracer_del(NULL, myself); rc = 0; - } else if (arg2 == PR_SET_PTRACER_ANY) { + } else if (arg2 == PR_SET_PTRACER_ANY || (int)arg2 == -1) { rc = yama_ptracer_add(NULL, myself); } else { struct task_struct *tracer; -- cgit v1.2.3 From 2fe5d6def1672ae6635dd71867bf36dcfaa7434b Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Mon, 13 Feb 2012 10:15:05 -0500 Subject: ima: integrity appraisal extension IMA currently maintains an integrity measurement list used to assert the integrity of the running system to a third party. The IMA-appraisal extension adds local integrity validation and enforcement of the measurement against a "good" value stored as an extended attribute 'security.ima'. The initial methods for validating 'security.ima' are hashed based, which provides file data integrity, and digital signature based, which in addition to providing file data integrity, provides authenticity. This patch creates and maintains the 'security.ima' xattr, containing the file data hash measurement. Protection of the xattr is provided by EVM, if enabled and configured. Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata integrity and, assuming success, compares the file's current hash value with the one stored as an extended attribute in 'security.ima'. Changelov v4: - changed iint cache flags to hex values Changelog v3: - change appraisal default for filesystems without xattr support to fail Changelog v2: - fix audit msg 'res' value - removed unused 'ima_appraise=' values Changelog v1: - removed unused iint mutex (Dmitry Kasatkin) - setattr hook must not reset appraised (Dmitry Kasatkin) - evm_verifyxattr() now differentiates between no 'security.evm' xattr (INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the 'security.evm' (INTEGRITY_NOXATTRS). - replace hash_status with ima_status (Dmitry Kasatkin) - re-initialize slab element ima_status on free (Dmitry Kasatkin) - include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA - merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin) - removed unnecessary error variable in process_measurement() (Dmitry Kasatkin) - use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured (moved ima_inode_post_setattr() to ima_appraise.c) - make sure ima_collect_measurement() can read file Changelog: - add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin) - fix the race condition between chmod, which takes the i_mutex and then iint->mutex, and ima_file_free() and process_measurement(), which take the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin) - cleanup of ima_appraise_measurement() (Dmitry Kasatkin) - changes as a result of the iint not allocated for all regular files, but only for those measured/appraised. - don't try to appraise new/empty files - expanded ima_appraisal description in ima/Kconfig - IMA appraise definitions required even if IMA_APPRAISE not enabled - add return value to ima_must_appraise() stub - unconditionally set status = INTEGRITY_PASS *after* testing status, not before. (Found by Joe Perches) Signed-off-by: Mimi Zohar Signed-off-by: Dmitry Kasatkin --- Documentation/kernel-parameters.txt | 4 + include/linux/xattr.h | 3 + security/integrity/evm/evm_main.c | 3 + security/integrity/iint.c | 3 +- security/integrity/ima/Kconfig | 15 +++ security/integrity/ima/Makefile | 1 + security/integrity/ima/ima.h | 37 +++++++- security/integrity/ima/ima_api.c | 50 +++++++--- security/integrity/ima/ima_appraise.c | 168 ++++++++++++++++++++++++++++++++++ security/integrity/ima/ima_crypto.c | 8 +- security/integrity/ima/ima_main.c | 79 +++++++++++----- security/integrity/ima/ima_policy.c | 32 +++++-- security/integrity/integrity.h | 8 +- 13 files changed, 358 insertions(+), 53 deletions(-) create mode 100644 security/integrity/ima/ima_appraise.c (limited to 'security') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index ad7e2e5088c1..fa09e64d9877 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1051,6 +1051,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. ihash_entries= [KNL] Set number of hash buckets for inode cache. + ima_appraise= [IMA] appraise integrity measurements + Format: { "off" | "enforce" | "fix" } + default: "enforce" + ima_audit= [IMA] Format: { "0" | "1" } 0 -- integrity auditing messages. (Default) diff --git a/include/linux/xattr.h b/include/linux/xattr.h index e5d122031542..77a3e686d566 100644 --- a/include/linux/xattr.h +++ b/include/linux/xattr.h @@ -33,6 +33,9 @@ #define XATTR_EVM_SUFFIX "evm" #define XATTR_NAME_EVM XATTR_SECURITY_PREFIX XATTR_EVM_SUFFIX +#define XATTR_IMA_SUFFIX "ima" +#define XATTR_NAME_IMA XATTR_SECURITY_PREFIX XATTR_IMA_SUFFIX + #define XATTR_SELINUX_SUFFIX "selinux" #define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 8901501425f4..eb5484504f50 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -33,6 +33,9 @@ char *evm_config_xattrnames[] = { #endif #ifdef CONFIG_SECURITY_SMACK XATTR_NAME_SMACK, +#endif +#ifdef CONFIG_IMA_APPRAISE + XATTR_NAME_IMA, #endif XATTR_NAME_CAPS, NULL diff --git a/security/integrity/iint.c b/security/integrity/iint.c index 399641c3e846..e600986aa49f 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -74,6 +74,7 @@ static void iint_free(struct integrity_iint_cache *iint) { iint->version = 0; iint->flags = 0UL; + iint->ima_status = INTEGRITY_UNKNOWN; iint->evm_status = INTEGRITY_UNKNOWN; kmem_cache_free(iint_cache, iint); } @@ -157,7 +158,7 @@ static void init_once(void *foo) memset(iint, 0, sizeof *iint); iint->version = 0; iint->flags = 0UL; - mutex_init(&iint->mutex); + iint->ima_status = INTEGRITY_UNKNOWN; iint->evm_status = INTEGRITY_UNKNOWN; } diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index 809ccf19d09c..d232c73647ae 100644 --- a/security/integrity/ima/Kconfig +++ b/security/integrity/ima/Kconfig @@ -56,3 +56,18 @@ config IMA_LSM_RULES default y help Disabling this option will disregard LSM based policy rules. + +config IMA_APPRAISE + bool "Appraise integrity measurements" + depends on IMA + default n + help + This option enables local measurement integrity appraisal. + It requires the system to be labeled with a security extended + attribute containing the file hash measurement. To protect + the security extended attributes from offline attack, enable + and configure EVM. + + For more information on integrity appraisal refer to: + + If unsure, say N. diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile index 5f740f6971e1..3f2ca6bdc384 100644 --- a/security/integrity/ima/Makefile +++ b/security/integrity/ima/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_IMA) += ima.o ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \ ima_policy.o ima-$(CONFIG_IMA_AUDIT) += ima_audit.o +ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index e7c99fd0d223..069a4aa63e95 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -40,6 +40,7 @@ enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 }; extern int ima_initialized; extern int ima_used_chip; extern char *ima_hash; +extern int ima_appraise; /* IMA inode template definition */ struct ima_template_data { @@ -107,6 +108,7 @@ static inline unsigned long ima_hash_key(u8 *digest) } /* LIM API function definitions */ +int ima_must_appraise_or_measure(struct inode *inode, int mask, int function); int ima_must_measure(struct inode *inode, int mask, int function); int ima_collect_measurement(struct integrity_iint_cache *iint, struct file *file); @@ -123,14 +125,45 @@ struct integrity_iint_cache *integrity_iint_insert(struct inode *inode); struct integrity_iint_cache *integrity_iint_find(struct inode *inode); /* IMA policy related functions */ -enum ima_hooks { FILE_CHECK = 1, FILE_MMAP, BPRM_CHECK }; +enum ima_hooks { FILE_CHECK = 1, FILE_MMAP, BPRM_CHECK, POST_SETATTR }; -int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask); +int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask, + int flags); void ima_init_policy(void); void ima_update_policy(void); ssize_t ima_parse_add_rule(char *); void ima_delete_rules(void); +/* Appraise integrity measurements */ +#define IMA_APPRAISE_ENFORCE 0x01 +#define IMA_APPRAISE_FIX 0x02 + +#ifdef CONFIG_IMA_APPRAISE +int ima_appraise_measurement(struct integrity_iint_cache *iint, + struct file *file, const unsigned char *filename); +int ima_must_appraise(struct inode *inode, enum ima_hooks func, int mask); +void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file); + +#else +static inline int ima_appraise_measurement(struct integrity_iint_cache *iint, + struct file *file, + const unsigned char *filename) +{ + return INTEGRITY_UNKNOWN; +} + +static inline int ima_must_appraise(struct inode *inode, + enum ima_hooks func, int mask) +{ + return 0; +} + +static inline void ima_update_xattr(struct integrity_iint_cache *iint, + struct file *file) +{ +} +#endif + /* LSM based policy rules require audit */ #ifdef CONFIG_IMA_LSM_RULES diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index 032ff03ad907..41cce84416c5 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -9,13 +9,17 @@ * License. * * File: ima_api.c - * Implements must_measure, collect_measurement, store_measurement, - * and store_template. + * Implements must_appraise_or_measure, collect_measurement, + * appraise_measurement, store_measurement and store_template. */ #include #include - +#include +#include +#include +#include #include "ima.h" + static const char *IMA_TEMPLATE_NAME = "ima"; /* @@ -93,7 +97,7 @@ err_out: } /** - * ima_must_measure - measure decision based on policy. + * ima_must_appraise_or_measure - appraise & measure decision based on policy. * @inode: pointer to inode to measure * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXECUTE) * @function: calling function (FILE_CHECK, BPRM_CHECK, FILE_MMAP) @@ -105,15 +109,22 @@ err_out: * mask: contains the permission mask * fsmagic: hex value * - * Return 0 to measure. For matching a DONT_MEASURE policy, no policy, - * or other error, return an error code. -*/ -int ima_must_measure(struct inode *inode, int mask, int function) + * Returns IMA_MEASURE, IMA_APPRAISE mask. + * + */ +int ima_must_appraise_or_measure(struct inode *inode, int mask, int function) { - int must_measure; + int flags = IMA_MEASURE | IMA_APPRAISE; + + if (!ima_appraise) + flags &= ~IMA_APPRAISE; + + return ima_match_policy(inode, function, mask, flags); +} - must_measure = ima_match_policy(inode, function, mask); - return must_measure ? 0 : -EACCES; +int ima_must_measure(struct inode *inode, int mask, int function) +{ + return ima_match_policy(inode, function, mask, IMA_MEASURE); } /* @@ -129,16 +140,24 @@ int ima_must_measure(struct inode *inode, int mask, int function) int ima_collect_measurement(struct integrity_iint_cache *iint, struct file *file) { - int result = -EEXIST; + struct inode *inode = file->f_dentry->d_inode; + const char *filename = file->f_dentry->d_name.name; + int result = 0; - if (!(iint->flags & IMA_MEASURED)) { + if (!(iint->flags & IMA_COLLECTED)) { u64 i_version = file->f_dentry->d_inode->i_version; memset(iint->digest, 0, IMA_DIGEST_SIZE); result = ima_calc_hash(file, iint->digest); - if (!result) + if (!result) { iint->version = i_version; + iint->flags |= IMA_COLLECTED; + } } + if (result) + integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, + filename, "collect_data", "failed", + result, 0); return result; } @@ -167,6 +186,9 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct ima_template_entry *entry; int violation = 0; + if (iint->flags & IMA_MEASURED) + return; + entry = kmalloc(sizeof(*entry), GFP_KERNEL); if (!entry) { integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename, diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c new file mode 100644 index 000000000000..4865f61f9044 --- /dev/null +++ b/security/integrity/ima/ima_appraise.c @@ -0,0 +1,168 @@ +/* + * Copyright (C) 2011 IBM Corporation + * + * Author: + * Mimi Zohar + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + */ +#include +#include +#include +#include +#include +#include +#include + +#include "ima.h" + +static int __init default_appraise_setup(char *str) +{ + if (strncmp(str, "off", 3) == 0) + ima_appraise = 0; + else if (strncmp(str, "fix", 3) == 0) + ima_appraise = IMA_APPRAISE_FIX; + return 1; +} + +__setup("ima_appraise=", default_appraise_setup); + +/* + * ima_must_appraise - set appraise flag + * + * Return 1 to appraise + */ +int ima_must_appraise(struct inode *inode, enum ima_hooks func, int mask) +{ + return 0; +} + +static void ima_fix_xattr(struct dentry *dentry, + struct integrity_iint_cache *iint) +{ + iint->digest[0] = IMA_XATTR_DIGEST; + __vfs_setxattr_noperm(dentry, XATTR_NAME_IMA, + iint->digest, IMA_DIGEST_SIZE + 1, 0); +} + +/* + * ima_appraise_measurement - appraise file measurement + * + * Call evm_verifyxattr() to verify the integrity of 'security.ima'. + * Assuming success, compare the xattr hash with the collected measurement. + * + * Return 0 on success, error code otherwise + */ +int ima_appraise_measurement(struct integrity_iint_cache *iint, + struct file *file, const unsigned char *filename) +{ + struct dentry *dentry = file->f_dentry; + struct inode *inode = dentry->d_inode; + u8 xattr_value[IMA_DIGEST_SIZE]; + enum integrity_status status = INTEGRITY_UNKNOWN; + const char *op = "appraise_data"; + char *cause = "unknown"; + int rc; + + if (!ima_appraise) + return 0; + if (!inode->i_op->getxattr) + return INTEGRITY_UNKNOWN; + + if (iint->flags & IMA_APPRAISED) + return iint->ima_status; + + rc = inode->i_op->getxattr(dentry, XATTR_NAME_IMA, xattr_value, + IMA_DIGEST_SIZE); + if (rc <= 0) { + if (rc && rc != -ENODATA) + goto out; + + cause = "missing-hash"; + status = + (inode->i_size == 0) ? INTEGRITY_PASS : INTEGRITY_NOLABEL; + goto out; + } + + status = evm_verifyxattr(dentry, XATTR_NAME_IMA, xattr_value, rc, iint); + if ((status != INTEGRITY_PASS) && (status != INTEGRITY_UNKNOWN)) { + if ((status == INTEGRITY_NOLABEL) + || (status == INTEGRITY_NOXATTRS)) + cause = "missing-HMAC"; + else if (status == INTEGRITY_FAIL) + cause = "invalid-HMAC"; + goto out; + } + + rc = memcmp(xattr_value, iint->digest, IMA_DIGEST_SIZE); + if (rc) { + status = INTEGRITY_FAIL; + cause = "invalid-hash"; + print_hex_dump_bytes("security.ima: ", DUMP_PREFIX_NONE, + xattr_value, IMA_DIGEST_SIZE); + print_hex_dump_bytes("collected: ", DUMP_PREFIX_NONE, + iint->digest, IMA_DIGEST_SIZE); + goto out; + } + status = INTEGRITY_PASS; + iint->flags |= IMA_APPRAISED; +out: + if (status != INTEGRITY_PASS) { + if (ima_appraise & IMA_APPRAISE_FIX) { + ima_fix_xattr(dentry, iint); + status = INTEGRITY_PASS; + } + integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename, + op, cause, rc, 0); + } + iint->ima_status = status; + return status; +} + +/* + * ima_update_xattr - update 'security.ima' hash value + */ +void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file) +{ + struct dentry *dentry = file->f_dentry; + int rc = 0; + + rc = ima_collect_measurement(iint, file); + if (rc < 0) + return; + ima_fix_xattr(dentry, iint); +} + +/** + * ima_inode_post_setattr - reflect file metadata changes + * @dentry: pointer to the affected dentry + * + * Changes to a dentry's metadata might result in needing to appraise. + * + * This function is called from notify_change(), which expects the caller + * to lock the inode's i_mutex. + */ +void ima_inode_post_setattr(struct dentry *dentry) +{ + struct inode *inode = dentry->d_inode; + struct integrity_iint_cache *iint; + int must_appraise, rc; + + if (!ima_initialized || !ima_appraise || !S_ISREG(inode->i_mode) + || !inode->i_op->removexattr) + return; + + must_appraise = ima_must_appraise(inode, MAY_ACCESS, POST_SETATTR); + iint = integrity_iint_find(inode); + if (iint) { + if (must_appraise) + iint->flags |= IMA_APPRAISE; + else + iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED); + } + if (!must_appraise) + rc = inode->i_op->removexattr(dentry, XATTR_NAME_IMA); + return; +} diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index 9b3ade7468b2..b21ee5b5495a 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -48,7 +48,7 @@ int ima_calc_hash(struct file *file, char *digest) struct scatterlist sg[1]; loff_t i_size, offset = 0; char *rbuf; - int rc; + int rc, read = 0; rc = init_desc(&desc); if (rc != 0) @@ -59,6 +59,10 @@ int ima_calc_hash(struct file *file, char *digest) rc = -ENOMEM; goto out; } + if (!(file->f_mode & FMODE_READ)) { + file->f_mode |= FMODE_READ; + read = 1; + } i_size = i_size_read(file->f_dentry->d_inode); while (offset < i_size) { int rbuf_len; @@ -80,6 +84,8 @@ int ima_calc_hash(struct file *file, char *digest) kfree(rbuf); if (!rc) rc = crypto_hash_final(&desc, digest); + if (read) + file->f_mode &= ~FMODE_READ; out: crypto_free_hash(desc.tfm); return rc; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index be8294915cf7..6eb28d47e74b 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -22,12 +22,19 @@ #include #include #include +#include #include #include "ima.h" int ima_initialized; +#ifdef CONFIG_IMA_APPRAISE +int ima_appraise = IMA_APPRAISE_ENFORCE; +#else +int ima_appraise; +#endif + char *ima_hash = "sha1"; static int __init hash_setup(char *str) { @@ -52,7 +59,7 @@ static void ima_rdwr_violation_check(struct file *file) struct dentry *dentry = file->f_path.dentry; struct inode *inode = dentry->d_inode; fmode_t mode = file->f_mode; - int rc; + int must_measure; bool send_tomtou = false, send_writers = false; unsigned char *pathname = NULL, *pathbuf = NULL; @@ -67,8 +74,8 @@ static void ima_rdwr_violation_check(struct file *file) goto out; } - rc = ima_must_measure(inode, MAY_READ, FILE_CHECK); - if (rc < 0) + must_measure = ima_must_measure(inode, MAY_READ, FILE_CHECK); + if (!must_measure) goto out; if (atomic_read(&inode->i_writecount) > 0) @@ -100,17 +107,21 @@ out: } static void ima_check_last_writer(struct integrity_iint_cache *iint, - struct inode *inode, - struct file *file) + struct inode *inode, struct file *file) { fmode_t mode = file->f_mode; - mutex_lock(&iint->mutex); - if (mode & FMODE_WRITE && - atomic_read(&inode->i_writecount) == 1 && - iint->version != inode->i_version) - iint->flags &= ~IMA_MEASURED; - mutex_unlock(&iint->mutex); + if (!(mode & FMODE_WRITE)) + return; + + mutex_lock(&inode->i_mutex); + if (atomic_read(&inode->i_writecount) == 1 && + iint->version != inode->i_version) { + iint->flags &= ~(IMA_COLLECTED | IMA_APPRAISED | IMA_MEASURED); + if (iint->flags & IMA_APPRAISE) + ima_update_xattr(iint, file); + } + mutex_unlock(&inode->i_mutex); } /** @@ -140,14 +151,17 @@ static int process_measurement(struct file *file, const unsigned char *filename, struct inode *inode = file->f_dentry->d_inode; struct integrity_iint_cache *iint; unsigned char *pathname = NULL, *pathbuf = NULL; - int rc = 0; + int rc = -ENOMEM, action, must_appraise; if (!ima_initialized || !S_ISREG(inode->i_mode)) return 0; - rc = ima_must_measure(inode, mask, function); - if (rc != 0) - return rc; + /* Determine if in appraise/measurement policy, + * returns IMA_MEASURE, IMA_APPRAISE bitmask. */ + action = ima_must_appraise_or_measure(inode, mask, function); + if (!action) + return 0; + retry: iint = integrity_iint_find(inode); if (!iint) { @@ -157,11 +171,21 @@ retry: return rc; } - mutex_lock(&iint->mutex); + must_appraise = action & IMA_APPRAISE; - rc = iint->flags & IMA_MEASURED ? 1 : 0; - if (rc != 0) + mutex_lock(&inode->i_mutex); + + /* Determine if already appraised/measured based on bitmask + * (IMA_MEASURE, IMA_MEASURED, IMA_APPRAISE, IMA_APPRAISED) */ + iint->flags |= action; + action &= ~((iint->flags & (IMA_MEASURED | IMA_APPRAISED)) >> 1); + + /* Nothing to do, just return existing appraised status */ + if (!action) { + if (iint->flags & IMA_APPRAISED) + rc = iint->ima_status; goto out; + } rc = ima_collect_measurement(iint, file); if (rc != 0) @@ -177,11 +201,16 @@ retry: pathname = NULL; } } - ima_store_measurement(iint, file, !pathname ? filename : pathname); + if (action & IMA_MEASURE) + ima_store_measurement(iint, file, + !pathname ? filename : pathname); + if (action & IMA_APPRAISE) + rc = ima_appraise_measurement(iint, file, + !pathname ? filename : pathname); kfree(pathbuf); out: - mutex_unlock(&iint->mutex); - return rc; + mutex_unlock(&inode->i_mutex); + return (rc && must_appraise) ? -EACCES : 0; } /** @@ -197,14 +226,14 @@ out: */ int ima_file_mmap(struct file *file, unsigned long prot) { - int rc; + int rc = 0; if (!file) return 0; if (prot & PROT_EXEC) rc = process_measurement(file, file->f_dentry->d_name.name, MAY_EXEC, FILE_MMAP); - return 0; + return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0; } /** @@ -228,7 +257,7 @@ int ima_bprm_check(struct linux_binprm *bprm) (strcmp(bprm->filename, bprm->interp) == 0) ? bprm->filename : bprm->interp, MAY_EXEC, BPRM_CHECK); - return 0; + return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0; } /** @@ -249,7 +278,7 @@ int ima_file_check(struct file *file, int mask) rc = process_measurement(file, file->f_dentry->d_name.name, mask & (MAY_READ | MAY_WRITE | MAY_EXEC), FILE_CHECK); - return 0; + return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0; } EXPORT_SYMBOL_GPL(ima_file_check); diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 1a9583008aae..3e22e17da295 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -25,7 +25,13 @@ #define IMA_FSMAGIC 0x0004 #define IMA_UID 0x0008 -enum ima_action { UNKNOWN = -1, DONT_MEASURE = 0, MEASURE }; +#define UNKNOWN 0 +#define MEASURE 1 /* same as IMA_MEASURE */ +#define DONT_MEASURE 2 +#define MEASURE_MASK 3 +#define APPRAISE 4 /* same as IMA_APPRAISE */ +#define DONT_APPRAISE 8 +#define APPRAISE_MASK 12 #define MAX_LSM_RULES 6 enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE, @@ -34,7 +40,7 @@ enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE, struct ima_measure_rule_entry { struct list_head list; - enum ima_action action; + int action; unsigned int flags; enum ima_hooks func; int mask; @@ -163,18 +169,28 @@ static bool ima_match_rules(struct ima_measure_rule_entry *rule, * as elements in the list are never deleted, nor does the list * change.) */ -int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask) +int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask, + int flags) { struct ima_measure_rule_entry *entry; + int action = 0, actmask = flags | (flags << 1); list_for_each_entry(entry, ima_measure, list) { - bool rc; - rc = ima_match_rules(entry, inode, func, mask); - if (rc) - return entry->action; + if (!(entry->action & actmask)) + continue; + + if (!ima_match_rules(entry, inode, func, mask)) + continue; + + action |= (entry->action & (IMA_APPRAISE | IMA_MEASURE)); + actmask &= (entry->action & APPRAISE_MASK) ? + ~APPRAISE_MASK : ~MEASURE_MASK; + if (!actmask) + break; } - return 0; + + return action; } /** diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 7a25ecec5aaa..dac6b68e945a 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -16,7 +16,11 @@ #include /* iint cache flags */ -#define IMA_MEASURED 0x01 +#define IMA_MEASURE 0x01 +#define IMA_MEASURED 0x02 +#define IMA_APPRAISE 0x04 +#define IMA_APPRAISED 0x08 +#define IMA_COLLECTED 0x10 enum evm_ima_xattr_type { IMA_XATTR_DIGEST = 0x01, @@ -36,7 +40,7 @@ struct integrity_iint_cache { u64 version; /* track inode changes */ unsigned char flags; u8 digest[SHA1_DIGEST_SIZE]; - struct mutex mutex; /* protects: version, flags, digest */ + enum integrity_status ima_status; enum integrity_status evm_status; }; -- cgit v1.2.3 From 07f6a79415d7d502ee0c7d02ace6594a7be7429a Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Wed, 9 Mar 2011 22:25:48 -0500 Subject: ima: add appraise action keywords and default rules Unlike the IMA measurement policy, the appraise policy can not be dependent on runtime process information, such as the task uid, as the 'security.ima' xattr is written on file close and must be updated each time the file changes, regardless of the current task uid. This patch extends the policy language with 'fowner', defines an appraise policy, which appraises all files owned by root, and defines 'ima_appraise_tcb', a new boot command line option, to enable the appraise policy. Changelog v3: - separate the measure from the appraise rules in order to support measuring without appraising and appraising without measuring. - change appraisal default for filesystems without xattr support to fail - update default appraise policy for cgroups Changelog v1: - don't appraise RAMFS (Dmitry Kasatkin) - merged rest of "ima: ima_must_appraise_or_measure API change" commit (Dmtiry Kasatkin) ima_must_appraise_or_measure() called ima_match_policy twice, which searched the policy for a matching rule. Once for a matching measurement rule and subsequently for an appraisal rule. Searching the policy twice is unnecessary overhead, which could be noticeable with a large policy. The new version of ima_must_appraise_or_measure() does everything in a single iteration using a new version of ima_match_policy(). It returns IMA_MEASURE, IMA_APPRAISE mask. With the use of action mask only one efficient matching function is enough. Removed other specific versions of matching functions. Changelog: - change 'owner' to 'fowner' to conform to the new LSM conditions posted by Roberto Sassu. - fix calls to ima_log_string() Signed-off-by: Mimi Zohar Signed-off-by: Dmitry Kasatkin --- Documentation/ABI/testing/ima_policy | 25 +++++- Documentation/kernel-parameters.txt | 4 + security/integrity/ima/ima_appraise.c | 5 +- security/integrity/ima/ima_policy.c | 151 +++++++++++++++++++++++++--------- 4 files changed, 141 insertions(+), 44 deletions(-) (limited to 'security') diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index 6cd6daefaaed..dcff82205477 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -12,11 +12,14 @@ Description: then closing the file. The new policy takes effect after the file ima/policy is closed. + IMA appraisal, if configured, uses these file measurements + for local measurement appraisal. + rule format: action [condition ...] - action: measure | dont_measure + action: measure | dont_measure | appraise | dont_appraise condition:= base | lsm - base: [[func=] [mask=] [fsmagic=] [uid=]] + base: [[func=] [mask=] [fsmagic=] [uid=] [fowner]] lsm: [[subj_user=] [subj_role=] [subj_type=] [obj_user=] [obj_role=] [obj_type=]] @@ -24,36 +27,50 @@ Description: mask:= [MAY_READ] [MAY_WRITE] [MAY_APPEND] [MAY_EXEC] fsmagic:= hex value uid:= decimal value + fowner:=decimal value lsm: are LSM specific default policy: # PROC_SUPER_MAGIC dont_measure fsmagic=0x9fa0 + dont_appraise fsmagic=0x9fa0 # SYSFS_MAGIC dont_measure fsmagic=0x62656572 + dont_appraise fsmagic=0x62656572 # DEBUGFS_MAGIC dont_measure fsmagic=0x64626720 + dont_appraise fsmagic=0x64626720 # TMPFS_MAGIC dont_measure fsmagic=0x01021994 + dont_appraise fsmagic=0x01021994 + # RAMFS_MAGIC + dont_measure fsmagic=0x858458f6 + dont_appraise fsmagic=0x858458f6 # SECURITYFS_MAGIC dont_measure fsmagic=0x73636673 + dont_appraise fsmagic=0x73636673 measure func=BPRM_CHECK measure func=FILE_MMAP mask=MAY_EXEC measure func=FILE_CHECK mask=MAY_READ uid=0 + appraise fowner=0 The default policy measures all executables in bprm_check, all files mmapped executable in file_mmap, and all files - open for read by root in do_filp_open. + open for read by root in do_filp_open. The default appraisal + policy appraises all files owned by root. Examples of LSM specific definitions: SELinux: # SELINUX_MAGIC - dont_measure fsmagic=0xF97CFF8C + dont_measure fsmagic=0xf97cff8c + dont_appraise fsmagic=0xf97cff8c dont_measure obj_type=var_log_t + dont_appraise obj_type=var_log_t dont_measure obj_type=auditd_log_t + dont_appraise obj_type=auditd_log_t measure subj_user=system_u func=FILE_CHECK mask=MAY_READ measure subj_role=system_r func=FILE_CHECK mask=MAY_READ diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index fa09e64d9877..949dddcfd177 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1055,6 +1055,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Format: { "off" | "enforce" | "fix" } default: "enforce" + ima_appraise_tcb [IMA] + The builtin appraise policy appraises all files + owned by uid=0. + ima_audit= [IMA] Format: { "0" | "1" } 0 -- integrity auditing messages. (Default) diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 4865f61f9044..681cb6e72257 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -36,7 +36,10 @@ __setup("ima_appraise=", default_appraise_setup); */ int ima_must_appraise(struct inode *inode, enum ima_hooks func, int mask) { - return 0; + if (!ima_appraise) + return 0; + + return ima_match_policy(inode, func, mask, IMA_APPRAISE); } static void ima_fix_xattr(struct dentry *dentry, diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 3e22e17da295..0d6d60b4ba6f 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -24,6 +24,7 @@ #define IMA_MASK 0x0002 #define IMA_FSMAGIC 0x0004 #define IMA_UID 0x0008 +#define IMA_FOWNER 0x0010 #define UNKNOWN 0 #define MEASURE 1 /* same as IMA_MEASURE */ @@ -38,7 +39,7 @@ enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE, LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE }; -struct ima_measure_rule_entry { +struct ima_rule_entry { struct list_head list; int action; unsigned int flags; @@ -46,6 +47,7 @@ struct ima_measure_rule_entry { int mask; unsigned long fsmagic; uid_t uid; + uid_t fowner; struct { void *rule; /* LSM file metadata specific */ int type; /* audit type */ @@ -54,7 +56,7 @@ struct ima_measure_rule_entry { /* * Without LSM specific knowledge, the default policy can only be - * written in terms of .action, .func, .mask, .fsmagic, and .uid + * written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner */ /* @@ -63,7 +65,7 @@ struct ima_measure_rule_entry { * normal users can easily run the machine out of memory simply building * and running executables. */ -static struct ima_measure_rule_entry default_rules[] = { +static struct ima_rule_entry default_rules[] = { {.action = DONT_MEASURE,.fsmagic = PROC_SUPER_MAGIC,.flags = IMA_FSMAGIC}, {.action = DONT_MEASURE,.fsmagic = SYSFS_MAGIC,.flags = IMA_FSMAGIC}, {.action = DONT_MEASURE,.fsmagic = DEBUGFS_MAGIC,.flags = IMA_FSMAGIC}, @@ -81,19 +83,41 @@ static struct ima_measure_rule_entry default_rules[] = { .flags = IMA_FUNC | IMA_MASK | IMA_UID}, }; -static LIST_HEAD(measure_default_rules); -static LIST_HEAD(measure_policy_rules); -static struct list_head *ima_measure; +static struct ima_rule_entry default_appraise_rules[] = { + {.action = DONT_APPRAISE,.fsmagic = PROC_SUPER_MAGIC,.flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE,.fsmagic = SYSFS_MAGIC,.flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE,.fsmagic = DEBUGFS_MAGIC,.flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE,.fsmagic = TMPFS_MAGIC,.flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE,.fsmagic = RAMFS_MAGIC,.flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE,.fsmagic = DEVPTS_SUPER_MAGIC,.flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE,.fsmagic = BINFMTFS_MAGIC,.flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE,.fsmagic = SECURITYFS_MAGIC,.flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE,.fsmagic = SELINUX_MAGIC,.flags = IMA_FSMAGIC}, + {.action = DONT_APPRAISE,.fsmagic = CGROUP_SUPER_MAGIC,.flags = IMA_FSMAGIC}, + {.action = APPRAISE,.fowner = 0,.flags = IMA_FOWNER}, +}; + +static LIST_HEAD(ima_default_rules); +static LIST_HEAD(ima_policy_rules); +static struct list_head *ima_rules; -static DEFINE_MUTEX(ima_measure_mutex); +static DEFINE_MUTEX(ima_rules_mutex); static bool ima_use_tcb __initdata; -static int __init default_policy_setup(char *str) +static int __init default_measure_policy_setup(char *str) { ima_use_tcb = 1; return 1; } -__setup("ima_tcb", default_policy_setup); +__setup("ima_tcb", default_measure_policy_setup); + +static bool ima_use_appraise_tcb __initdata; +static int __init default_appraise_policy_setup(char *str) +{ + ima_use_appraise_tcb = 1; + return 1; +} +__setup("ima_appraise_tcb", default_appraise_policy_setup); /** * ima_match_rules - determine whether an inode matches the measure rule. @@ -104,7 +128,7 @@ __setup("ima_tcb", default_policy_setup); * * Returns true on rule match, false on failure. */ -static bool ima_match_rules(struct ima_measure_rule_entry *rule, +static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, enum ima_hooks func, int mask) { struct task_struct *tsk = current; @@ -120,6 +144,8 @@ static bool ima_match_rules(struct ima_measure_rule_entry *rule, return false; if ((rule->flags & IMA_UID) && rule->uid != cred->uid) return false; + if ((rule->flags & IMA_FOWNER) && rule->fowner != inode->i_uid) + return false; for (i = 0; i < MAX_LSM_RULES; i++) { int rc = 0; u32 osid, sid; @@ -172,10 +198,10 @@ static bool ima_match_rules(struct ima_measure_rule_entry *rule, int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask, int flags) { - struct ima_measure_rule_entry *entry; + struct ima_rule_entry *entry; int action = 0, actmask = flags | (flags << 1); - list_for_each_entry(entry, ima_measure, list) { + list_for_each_entry(entry, ima_rules, list) { if (!(entry->action & actmask)) continue; @@ -196,22 +222,31 @@ int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask, /** * ima_init_policy - initialize the default measure rules. * - * ima_measure points to either the measure_default_rules or the - * the new measure_policy_rules. + * ima_rules points to either the ima_default_rules or the + * the new ima_policy_rules. */ void __init ima_init_policy(void) { - int i, entries; + int i, measure_entries, appraise_entries; /* if !ima_use_tcb set entries = 0 so we load NO default rules */ - if (ima_use_tcb) - entries = ARRAY_SIZE(default_rules); - else - entries = 0; - - for (i = 0; i < entries; i++) - list_add_tail(&default_rules[i].list, &measure_default_rules); - ima_measure = &measure_default_rules; + measure_entries = ima_use_tcb ? ARRAY_SIZE(default_rules) : 0; + appraise_entries = ima_use_appraise_tcb ? + ARRAY_SIZE(default_appraise_rules) : 0; + + for (i = 0; i < measure_entries + appraise_entries; i++) { + if (i < measure_entries) + list_add_tail(&default_rules[i].list, + &ima_default_rules); + else { + int j = i - measure_entries; + + list_add_tail(&default_appraise_rules[j].list, + &ima_default_rules); + } + } + + ima_rules = &ima_default_rules; } /** @@ -228,8 +263,8 @@ void ima_update_policy(void) int result = 1; int audit_info = 0; - if (ima_measure == &measure_default_rules) { - ima_measure = &measure_policy_rules; + if (ima_rules == &ima_default_rules) { + ima_rules = &ima_policy_rules; cause = "complete"; result = 0; } @@ -240,14 +275,17 @@ void ima_update_policy(void) enum { Opt_err = -1, Opt_measure = 1, Opt_dont_measure, + Opt_appraise, Opt_dont_appraise, Opt_obj_user, Opt_obj_role, Opt_obj_type, Opt_subj_user, Opt_subj_role, Opt_subj_type, - Opt_func, Opt_mask, Opt_fsmagic, Opt_uid + Opt_func, Opt_mask, Opt_fsmagic, Opt_uid, Opt_fowner }; static match_table_t policy_tokens = { {Opt_measure, "measure"}, {Opt_dont_measure, "dont_measure"}, + {Opt_appraise, "appraise"}, + {Opt_dont_appraise, "dont_appraise"}, {Opt_obj_user, "obj_user=%s"}, {Opt_obj_role, "obj_role=%s"}, {Opt_obj_type, "obj_type=%s"}, @@ -258,10 +296,11 @@ static match_table_t policy_tokens = { {Opt_mask, "mask=%s"}, {Opt_fsmagic, "fsmagic=%s"}, {Opt_uid, "uid=%s"}, + {Opt_fowner, "fowner=%s"}, {Opt_err, NULL} }; -static int ima_lsm_rule_init(struct ima_measure_rule_entry *entry, +static int ima_lsm_rule_init(struct ima_rule_entry *entry, char *args, int lsm_rule, int audit_type) { int result; @@ -285,7 +324,7 @@ static void ima_log_string(struct audit_buffer *ab, char *key, char *value) audit_log_format(ab, " "); } -static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry) +static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) { struct audit_buffer *ab; char *p; @@ -294,6 +333,7 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry) ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_INTEGRITY_RULE); entry->uid = -1; + entry->fowner = -1; entry->action = UNKNOWN; while ((p = strsep(&rule, " \t")) != NULL) { substring_t args[MAX_OPT_ARGS]; @@ -322,11 +362,27 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry) entry->action = DONT_MEASURE; break; + case Opt_appraise: + ima_log_string(ab, "action", "appraise"); + + if (entry->action != UNKNOWN) + result = -EINVAL; + + entry->action = APPRAISE; + break; + case Opt_dont_appraise: + ima_log_string(ab, "action", "dont_appraise"); + + if (entry->action != UNKNOWN) + result = -EINVAL; + + entry->action = DONT_APPRAISE; + break; case Opt_func: ima_log_string(ab, "func", args[0].from); if (entry->func) - result = -EINVAL; + result = -EINVAL; if (strcmp(args[0].from, "FILE_CHECK") == 0) entry->func = FILE_CHECK; @@ -391,6 +447,23 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry) entry->flags |= IMA_UID; } break; + case Opt_fowner: + ima_log_string(ab, "fowner", args[0].from); + + if (entry->fowner != -1) { + result = -EINVAL; + break; + } + + result = strict_strtoul(args[0].from, 10, &lnum); + if (!result) { + entry->fowner = (uid_t) lnum; + if (entry->fowner != lnum) + result = -EINVAL; + else + entry->flags |= IMA_FOWNER; + } + break; case Opt_obj_user: ima_log_string(ab, "obj_user", args[0].from); result = ima_lsm_rule_init(entry, args[0].from, @@ -442,7 +515,7 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry) } /** - * ima_parse_add_rule - add a rule to measure_policy_rules + * ima_parse_add_rule - add a rule to ima_policy_rules * @rule - ima measurement policy rule * * Uses a mutex to protect the policy list from multiple concurrent writers. @@ -452,12 +525,12 @@ ssize_t ima_parse_add_rule(char *rule) { const char *op = "update_policy"; char *p; - struct ima_measure_rule_entry *entry; + struct ima_rule_entry *entry; ssize_t result, len; int audit_info = 0; /* Prevent installed policy from changing */ - if (ima_measure != &measure_default_rules) { + if (ima_rules != &ima_default_rules) { integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL, op, "already exists", -EACCES, audit_info); @@ -490,9 +563,9 @@ ssize_t ima_parse_add_rule(char *rule) return result; } - mutex_lock(&ima_measure_mutex); - list_add_tail(&entry->list, &measure_policy_rules); - mutex_unlock(&ima_measure_mutex); + mutex_lock(&ima_rules_mutex); + list_add_tail(&entry->list, &ima_policy_rules); + mutex_unlock(&ima_rules_mutex); return len; } @@ -500,12 +573,12 @@ ssize_t ima_parse_add_rule(char *rule) /* ima_delete_rules called to cleanup invalid policy */ void ima_delete_rules(void) { - struct ima_measure_rule_entry *entry, *tmp; + struct ima_rule_entry *entry, *tmp; - mutex_lock(&ima_measure_mutex); - list_for_each_entry_safe(entry, tmp, &measure_policy_rules, list) { + mutex_lock(&ima_rules_mutex); + list_for_each_entry_safe(entry, tmp, &ima_policy_rules, list) { list_del(&entry->list); kfree(entry); } - mutex_unlock(&ima_measure_mutex); + mutex_unlock(&ima_rules_mutex); } -- cgit v1.2.3 From bf2276d10ce58ff44ab8857266a6718024496af6 Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Wed, 19 Oct 2011 12:04:40 +0300 Subject: ima: allocating iint improvements With IMA-appraisal's removal of the iint mutex and taking the i_mutex instead, allocating the iint becomes a lot simplier, as we don't need to be concerned with two processes racing to allocate the iint. This patch cleans up and improves performance for allocating the iint. - removed redundant double i_mutex locking - combined iint allocation with tree search Changelog v2: - removed the rwlock/read_lock changes from this patch Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- include/linux/integrity.h | 7 +++--- security/integrity/iint.c | 45 +++++++++++++++++---------------------- security/integrity/ima/ima_main.c | 13 ++++------- 3 files changed, 27 insertions(+), 38 deletions(-) (limited to 'security') diff --git a/include/linux/integrity.h b/include/linux/integrity.h index a0c41256cb92..66c5fe9550a5 100644 --- a/include/linux/integrity.h +++ b/include/linux/integrity.h @@ -22,13 +22,14 @@ enum integrity_status { /* List of EVM protected security xattrs */ #ifdef CONFIG_INTEGRITY -extern int integrity_inode_alloc(struct inode *inode); +extern struct integrity_iint_cache *integrity_inode_get(struct inode *inode); extern void integrity_inode_free(struct inode *inode); #else -static inline int integrity_inode_alloc(struct inode *inode) +static inline struct integrity_iint_cache * + integrity_inode_get(struct inode *inode) { - return 0; + return NULL; } static inline void integrity_inode_free(struct inode *inode) diff --git a/security/integrity/iint.c b/security/integrity/iint.c index e600986aa49f..c91a436e13ac 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -80,24 +80,26 @@ static void iint_free(struct integrity_iint_cache *iint) } /** - * integrity_inode_alloc - allocate an iint associated with an inode + * integrity_inode_get - find or allocate an iint associated with an inode * @inode: pointer to the inode + * @return: allocated iint + * + * Caller must lock i_mutex */ -int integrity_inode_alloc(struct inode *inode) +struct integrity_iint_cache *integrity_inode_get(struct inode *inode) { struct rb_node **p; - struct rb_node *new_node, *parent = NULL; - struct integrity_iint_cache *new_iint, *test_iint; - int rc; + struct rb_node *node, *parent = NULL; + struct integrity_iint_cache *iint, *test_iint; - new_iint = kmem_cache_alloc(iint_cache, GFP_NOFS); - if (!new_iint) - return -ENOMEM; + iint = integrity_iint_find(inode); + if (iint) + return iint; - new_iint->inode = inode; - new_node = &new_iint->rb_node; + iint = kmem_cache_alloc(iint_cache, GFP_NOFS); + if (!iint) + return NULL; - mutex_lock(&inode->i_mutex); /* i_flags */ spin_lock(&integrity_iint_lock); p = &integrity_iint_tree.rb_node; @@ -105,29 +107,20 @@ int integrity_inode_alloc(struct inode *inode) parent = *p; test_iint = rb_entry(parent, struct integrity_iint_cache, rb_node); - rc = -EEXIST; if (inode < test_iint->inode) p = &(*p)->rb_left; - else if (inode > test_iint->inode) - p = &(*p)->rb_right; else - goto out_err; + p = &(*p)->rb_right; } + iint->inode = inode; + node = &iint->rb_node; inode->i_flags |= S_IMA; - rb_link_node(new_node, parent, p); - rb_insert_color(new_node, &integrity_iint_tree); + rb_link_node(node, parent, p); + rb_insert_color(node, &integrity_iint_tree); spin_unlock(&integrity_iint_lock); - mutex_unlock(&inode->i_mutex); /* i_flags */ - - return 0; -out_err: - spin_unlock(&integrity_iint_lock); - mutex_unlock(&inode->i_mutex); /* i_flags */ - iint_free(new_iint); - - return rc; + return iint; } /** diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 6eb28d47e74b..df6521296051 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -162,19 +162,14 @@ static int process_measurement(struct file *file, const unsigned char *filename, if (!action) return 0; -retry: - iint = integrity_iint_find(inode); - if (!iint) { - rc = integrity_inode_alloc(inode); - if (!rc || rc == -EEXIST) - goto retry; - return rc; - } - must_appraise = action & IMA_APPRAISE; mutex_lock(&inode->i_mutex); + iint = integrity_inode_get(inode); + if (!iint) + goto out; + /* Determine if already appraised/measured based on bitmask * (IMA_MEASURE, IMA_MEASURED, IMA_APPRAISE, IMA_APPRAISED) */ iint->flags |= action; -- cgit v1.2.3 From a10bf26b2f53242836e9362c6c9c857b627b82a9 Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Wed, 8 Feb 2012 14:15:42 -0500 Subject: ima: replace iint spinblock with rwlock/read_lock For performance, replace the iint spinlock with rwlock/read_lock. Eric Paris questioned this change, from spinlocks to rwlocks, saying "rwlocks have been shown to actually be slower on multi processor systems in a number of cases due to the cache line bouncing required." Based on performance measurements compiling the kernel on a cold boot with multiple jobs with/without this patch, Dmitry Kasatkin and I found that rwlocks performed better than spinlocks, but very insignificantly. For example with total compilation time around 6 minutes, with rwlocks time was 1 - 3 seconds shorter... but always like that. Changelog v2: - new patch taken from the 'allocating iint improvements' patch Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- security/integrity/iint.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) (limited to 'security') diff --git a/security/integrity/iint.c b/security/integrity/iint.c index c91a436e13ac..d82a5a13d855 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -22,7 +22,7 @@ #include "integrity.h" static struct rb_root integrity_iint_tree = RB_ROOT; -static DEFINE_SPINLOCK(integrity_iint_lock); +static DEFINE_RWLOCK(integrity_iint_lock); static struct kmem_cache *iint_cache __read_mostly; int iint_initialized; @@ -35,8 +35,6 @@ static struct integrity_iint_cache *__integrity_iint_find(struct inode *inode) struct integrity_iint_cache *iint; struct rb_node *n = integrity_iint_tree.rb_node; - assert_spin_locked(&integrity_iint_lock); - while (n) { iint = rb_entry(n, struct integrity_iint_cache, rb_node); @@ -63,9 +61,9 @@ struct integrity_iint_cache *integrity_iint_find(struct inode *inode) if (!IS_IMA(inode)) return NULL; - spin_lock(&integrity_iint_lock); + read_lock(&integrity_iint_lock); iint = __integrity_iint_find(inode); - spin_unlock(&integrity_iint_lock); + read_unlock(&integrity_iint_lock); return iint; } @@ -100,7 +98,7 @@ struct integrity_iint_cache *integrity_inode_get(struct inode *inode) if (!iint) return NULL; - spin_lock(&integrity_iint_lock); + write_lock(&integrity_iint_lock); p = &integrity_iint_tree.rb_node; while (*p) { @@ -119,7 +117,7 @@ struct integrity_iint_cache *integrity_inode_get(struct inode *inode) rb_link_node(node, parent, p); rb_insert_color(node, &integrity_iint_tree); - spin_unlock(&integrity_iint_lock); + write_unlock(&integrity_iint_lock); return iint; } @@ -136,10 +134,10 @@ void integrity_inode_free(struct inode *inode) if (!IS_IMA(inode)) return; - spin_lock(&integrity_iint_lock); + write_lock(&integrity_iint_lock); iint = __integrity_iint_find(inode); rb_erase(&iint->rb_node, &integrity_iint_tree); - spin_unlock(&integrity_iint_lock); + write_unlock(&integrity_iint_lock); iint_free(iint); } -- cgit v1.2.3 From 42c63330f2b05aa6077c1bfc2798c04afe54f6b2 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Thu, 10 Mar 2011 18:54:15 -0500 Subject: ima: add ima_inode_setxattr/removexattr function and calls Based on xattr_permission comments, the restriction to modify 'security' xattr is left up to the underlying fs or lsm. Ensure that not just anyone can modify or remove 'security.ima'. Changelog v1: - Unless IMA-APPRAISE is configured, use stub ima_inode_removexattr()/setxattr() functions. (Moved ima_inode_removexattr()/setxattr() to ima_appraise.c) Changelog: - take i_mutex to fix locking (Dmitry Kasatkin) - ima_reset_appraise_flags should only be called when modifying or removing the 'security.ima' xattr. Requires CAP_SYS_ADMIN privilege. (Incorporated fix from Roberto Sassu) - Even if allowed to update security.ima, reset the appraisal flags, forcing re-appraisal. - Replace CAP_MAC_ADMIN with CAP_SYS_ADMIN - static inline ima_inode_setxattr()/ima_inode_removexattr() stubs - ima_protect_xattr should be static Signed-off-by: Mimi Zohar Signed-off-by: Dmitry Kasatkin --- include/linux/ima.h | 17 +++++++++++ security/integrity/ima/ima_appraise.c | 57 +++++++++++++++++++++++++++++++++++ security/security.c | 6 ++++ 3 files changed, 80 insertions(+) (limited to 'security') diff --git a/include/linux/ima.h b/include/linux/ima.h index e2bfbb1e9af6..2c7223d7e73b 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -44,10 +44,27 @@ static inline int ima_file_mmap(struct file *file, unsigned long prot) #ifdef CONFIG_IMA_APPRAISE extern void ima_inode_post_setattr(struct dentry *dentry); +extern int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name, + const void *xattr_value, size_t xattr_value_len); +extern int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name); #else static inline void ima_inode_post_setattr(struct dentry *dentry) { return; } + +static inline int ima_inode_setxattr(struct dentry *dentry, + const char *xattr_name, + const void *xattr_value, + size_t xattr_value_len) +{ + return 0; +} + +static inline int ima_inode_removexattr(struct dentry *dentry, + const char *xattr_name) +{ + return 0; +} #endif /* CONFIG_IMA_APPRAISE_H */ #endif /* _LINUX_IMA_H */ diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 681cb6e72257..becc7e09116d 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -169,3 +169,60 @@ void ima_inode_post_setattr(struct dentry *dentry) rc = inode->i_op->removexattr(dentry, XATTR_NAME_IMA); return; } + +/* + * ima_protect_xattr - protect 'security.ima' + * + * Ensure that not just anyone can modify or remove 'security.ima'. + */ +static int ima_protect_xattr(struct dentry *dentry, const char *xattr_name, + const void *xattr_value, size_t xattr_value_len) +{ + if (strcmp(xattr_name, XATTR_NAME_IMA) == 0) { + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + return 1; + } + return 0; +} + +static void ima_reset_appraise_flags(struct inode *inode) +{ + struct integrity_iint_cache *iint; + + if (!ima_initialized || !ima_appraise || !S_ISREG(inode->i_mode)) + return; + + iint = integrity_iint_find(inode); + if (!iint) + return; + + iint->flags &= ~(IMA_COLLECTED | IMA_APPRAISED | IMA_MEASURED); + return; +} + +int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name, + const void *xattr_value, size_t xattr_value_len) +{ + int result; + + result = ima_protect_xattr(dentry, xattr_name, xattr_value, + xattr_value_len); + if (result == 1) { + ima_reset_appraise_flags(dentry->d_inode); + result = 0; + } + return result; +} + +int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name) +{ + int result; + + result = ima_protect_xattr(dentry, xattr_name, NULL, 0); + if (result == 1) { + ima_reset_appraise_flags(dentry->d_inode); + result = 0; + } + return result; +} diff --git a/security/security.c b/security/security.c index 68c1b9b45d93..d23b43522a5a 100644 --- a/security/security.c +++ b/security/security.c @@ -571,6 +571,9 @@ int security_inode_setxattr(struct dentry *dentry, const char *name, if (unlikely(IS_PRIVATE(dentry->d_inode))) return 0; ret = security_ops->inode_setxattr(dentry, name, value, size, flags); + if (ret) + return ret; + ret = ima_inode_setxattr(dentry, name, value, size); if (ret) return ret; return evm_inode_setxattr(dentry, name, value, size); @@ -606,6 +609,9 @@ int security_inode_removexattr(struct dentry *dentry, const char *name) if (unlikely(IS_PRIVATE(dentry->d_inode))) return 0; ret = security_ops->inode_removexattr(dentry, name); + if (ret) + return ret; + ret = ima_inode_removexattr(dentry, name); if (ret) return ret; return evm_inode_removexattr(dentry, name); -- cgit v1.2.3 From 5a44b41207174e1882ce0c24a752f4cfb65dab07 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Mon, 9 Jan 2012 22:59:36 -0500 Subject: ima: add support for different security.ima data types IMA-appraisal currently verifies the integrity of a file based on a known 'good' measurement value. This patch reserves the first byte of 'security.ima' as a place holder for the type of method used for verifying file data integrity. Changelog v1: - Use the newly defined 'struct evm_ima_xattr_data' Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- security/integrity/ima/ima_api.c | 6 +++--- security/integrity/ima/ima_appraise.c | 23 +++++++++++++---------- security/integrity/integrity.h | 2 +- 3 files changed, 17 insertions(+), 14 deletions(-) (limited to 'security') diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index 41cce84416c5..33d46859753a 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -147,8 +147,8 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, if (!(iint->flags & IMA_COLLECTED)) { u64 i_version = file->f_dentry->d_inode->i_version; - memset(iint->digest, 0, IMA_DIGEST_SIZE); - result = ima_calc_hash(file, iint->digest); + iint->ima_xattr.type = IMA_XATTR_DIGEST; + result = ima_calc_hash(file, iint->ima_xattr.digest); if (!result) { iint->version = i_version; iint->flags |= IMA_COLLECTED; @@ -196,7 +196,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint, return; } memset(&entry->template, 0, sizeof(entry->template)); - memcpy(entry->template.digest, iint->digest, IMA_DIGEST_SIZE); + memcpy(entry->template.digest, iint->ima_xattr.digest, IMA_DIGEST_SIZE); strcpy(entry->template.file_name, (strlen(filename) > IMA_EVENT_NAME_LEN_MAX) ? file->f_dentry->d_name.name : filename); diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index becc7e09116d..f9979976aa5d 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -45,9 +45,9 @@ int ima_must_appraise(struct inode *inode, enum ima_hooks func, int mask) static void ima_fix_xattr(struct dentry *dentry, struct integrity_iint_cache *iint) { - iint->digest[0] = IMA_XATTR_DIGEST; - __vfs_setxattr_noperm(dentry, XATTR_NAME_IMA, - iint->digest, IMA_DIGEST_SIZE + 1, 0); + iint->ima_xattr.type = IMA_XATTR_DIGEST; + __vfs_setxattr_noperm(dentry, XATTR_NAME_IMA, (u8 *)&iint->ima_xattr, + sizeof iint->ima_xattr, 0); } /* @@ -63,7 +63,7 @@ int ima_appraise_measurement(struct integrity_iint_cache *iint, { struct dentry *dentry = file->f_dentry; struct inode *inode = dentry->d_inode; - u8 xattr_value[IMA_DIGEST_SIZE]; + struct evm_ima_xattr_data xattr_value; enum integrity_status status = INTEGRITY_UNKNOWN; const char *op = "appraise_data"; char *cause = "unknown"; @@ -77,8 +77,8 @@ int ima_appraise_measurement(struct integrity_iint_cache *iint, if (iint->flags & IMA_APPRAISED) return iint->ima_status; - rc = inode->i_op->getxattr(dentry, XATTR_NAME_IMA, xattr_value, - IMA_DIGEST_SIZE); + rc = inode->i_op->getxattr(dentry, XATTR_NAME_IMA, (u8 *)&xattr_value, + sizeof xattr_value); if (rc <= 0) { if (rc && rc != -ENODATA) goto out; @@ -89,7 +89,8 @@ int ima_appraise_measurement(struct integrity_iint_cache *iint, goto out; } - status = evm_verifyxattr(dentry, XATTR_NAME_IMA, xattr_value, rc, iint); + status = evm_verifyxattr(dentry, XATTR_NAME_IMA, (u8 *)&xattr_value, + rc, iint); if ((status != INTEGRITY_PASS) && (status != INTEGRITY_UNKNOWN)) { if ((status == INTEGRITY_NOLABEL) || (status == INTEGRITY_NOXATTRS)) @@ -99,14 +100,16 @@ int ima_appraise_measurement(struct integrity_iint_cache *iint, goto out; } - rc = memcmp(xattr_value, iint->digest, IMA_DIGEST_SIZE); + rc = memcmp(xattr_value.digest, iint->ima_xattr.digest, + IMA_DIGEST_SIZE); if (rc) { status = INTEGRITY_FAIL; cause = "invalid-hash"; print_hex_dump_bytes("security.ima: ", DUMP_PREFIX_NONE, - xattr_value, IMA_DIGEST_SIZE); + &xattr_value, sizeof xattr_value); print_hex_dump_bytes("collected: ", DUMP_PREFIX_NONE, - iint->digest, IMA_DIGEST_SIZE); + (u8 *)&iint->ima_xattr, + sizeof iint->ima_xattr); goto out; } status = INTEGRITY_PASS; diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index dac6b68e945a..91ccef1c704b 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -39,7 +39,7 @@ struct integrity_iint_cache { struct inode *inode; /* back pointer to inode in question */ u64 version; /* track inode changes */ unsigned char flags; - u8 digest[SHA1_DIGEST_SIZE]; + struct evm_ima_xattr_data ima_xattr; enum integrity_status ima_status; enum integrity_status evm_status; }; -- cgit v1.2.3 From 8606404fa555c2ee691376fcc640ab89fe752035 Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Wed, 31 Aug 2011 14:07:06 +0300 Subject: ima: digital signature verification support This patch adds support for digital signature based integrity appraisal. With this patch, 'security.ima' contains either the file data hash or a digital signature of the file data hash. The file data hash provides the security attribute of file integrity. In addition to file integrity, a digital signature provides the security attribute of authenticity. Unlike EVM, when the file metadata changes, the digital signature is replaced with an HMAC, modification of the file data does not cause the 'security.ima' digital signature to be replaced with a hash. As a result, after any modification, subsequent file integrity appraisals would fail. Although digitally signed files can be modified, but by not updating 'security.ima' to reflect these modifications, in essence digitally signed files could be considered 'immutable'. IMA uses a different keyring than EVM. While the EVM keyring should not be updated after initialization and locked, the IMA keyring should allow updating or adding new keys when upgrading or installing packages. Changelog v4: - Change IMA_DIGSIG to hex equivalent Changelog v3: - Permit files without any 'security.ima' xattr to be labeled properly. Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- security/integrity/ima/ima_appraise.c | 70 +++++++++++++++++++++++++---------- security/integrity/integrity.h | 1 + 2 files changed, 52 insertions(+), 19 deletions(-) (limited to 'security') diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index f9979976aa5d..4cdf36ad884a 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -63,7 +63,7 @@ int ima_appraise_measurement(struct integrity_iint_cache *iint, { struct dentry *dentry = file->f_dentry; struct inode *inode = dentry->d_inode; - struct evm_ima_xattr_data xattr_value; + struct evm_ima_xattr_data *xattr_value = NULL; enum integrity_status status = INTEGRITY_UNKNOWN; const char *op = "appraise_data"; char *cause = "unknown"; @@ -77,8 +77,8 @@ int ima_appraise_measurement(struct integrity_iint_cache *iint, if (iint->flags & IMA_APPRAISED) return iint->ima_status; - rc = inode->i_op->getxattr(dentry, XATTR_NAME_IMA, (u8 *)&xattr_value, - sizeof xattr_value); + rc = vfs_getxattr_alloc(dentry, XATTR_NAME_IMA, (char **)&xattr_value, + 0, GFP_NOFS); if (rc <= 0) { if (rc && rc != -ENODATA) goto out; @@ -89,8 +89,7 @@ int ima_appraise_measurement(struct integrity_iint_cache *iint, goto out; } - status = evm_verifyxattr(dentry, XATTR_NAME_IMA, (u8 *)&xattr_value, - rc, iint); + status = evm_verifyxattr(dentry, XATTR_NAME_IMA, xattr_value, rc, iint); if ((status != INTEGRITY_PASS) && (status != INTEGRITY_UNKNOWN)) { if ((status == INTEGRITY_NOLABEL) || (status == INTEGRITY_NOXATTRS)) @@ -100,30 +99,58 @@ int ima_appraise_measurement(struct integrity_iint_cache *iint, goto out; } - rc = memcmp(xattr_value.digest, iint->ima_xattr.digest, - IMA_DIGEST_SIZE); - if (rc) { - status = INTEGRITY_FAIL; - cause = "invalid-hash"; - print_hex_dump_bytes("security.ima: ", DUMP_PREFIX_NONE, - &xattr_value, sizeof xattr_value); - print_hex_dump_bytes("collected: ", DUMP_PREFIX_NONE, - (u8 *)&iint->ima_xattr, - sizeof iint->ima_xattr); - goto out; + switch (xattr_value->type) { + case IMA_XATTR_DIGEST: + rc = memcmp(xattr_value->digest, iint->ima_xattr.digest, + IMA_DIGEST_SIZE); + if (rc) { + cause = "invalid-hash"; + status = INTEGRITY_FAIL; + print_hex_dump_bytes("security.ima: ", DUMP_PREFIX_NONE, + xattr_value, sizeof(*xattr_value)); + print_hex_dump_bytes("collected: ", DUMP_PREFIX_NONE, + (u8 *)&iint->ima_xattr, + sizeof iint->ima_xattr); + break; + } + status = INTEGRITY_PASS; + break; + case EVM_IMA_XATTR_DIGSIG: + iint->flags |= IMA_DIGSIG; + rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA, + xattr_value->digest, rc - 1, + iint->ima_xattr.digest, + IMA_DIGEST_SIZE); + if (rc == -EOPNOTSUPP) { + status = INTEGRITY_UNKNOWN; + } else if (rc) { + cause = "invalid-signature"; + status = INTEGRITY_FAIL; + } else { + status = INTEGRITY_PASS; + } + break; + default: + status = INTEGRITY_UNKNOWN; + cause = "unknown-ima-data"; + break; } - status = INTEGRITY_PASS; - iint->flags |= IMA_APPRAISED; + out: if (status != INTEGRITY_PASS) { - if (ima_appraise & IMA_APPRAISE_FIX) { + if ((ima_appraise & IMA_APPRAISE_FIX) && + (!xattr_value || + xattr_value->type != EVM_IMA_XATTR_DIGSIG)) { ima_fix_xattr(dentry, iint); status = INTEGRITY_PASS; } integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename, op, cause, rc, 0); + } else { + iint->flags |= IMA_APPRAISED; } iint->ima_status = status; + kfree(xattr_value); return status; } @@ -135,9 +162,14 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file) struct dentry *dentry = file->f_dentry; int rc = 0; + /* do not collect and update hash for digital signatures */ + if (iint->flags & IMA_DIGSIG) + return; + rc = ima_collect_measurement(iint, file); if (rc < 0) return; + ima_fix_xattr(dentry, iint); } diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 91ccef1c704b..4eec1b14193e 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -21,6 +21,7 @@ #define IMA_APPRAISE 0x04 #define IMA_APPRAISED 0x08 #define IMA_COLLECTED 0x10 +#define IMA_DIGSIG 0x20 enum evm_ima_xattr_type { IMA_XATTR_DIGEST = 0x01, -- cgit v1.2.3 From d9d300cdb6f233c4c591348919c758062198a4f4 Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Wed, 27 Jun 2012 11:26:14 +0300 Subject: ima: rename ima_must_appraise_or_measure When AUDIT action support is added to the IMA, ima_must_appraise_or_measure() does not reflect the real meaning anymore. Rename it to ima_get_action(). Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- security/integrity/ima/ima.h | 2 +- security/integrity/ima/ima_api.c | 4 ++-- security/integrity/ima/ima_main.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) (limited to 'security') diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 069a4aa63e95..48aa0d46d3e7 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -108,7 +108,7 @@ static inline unsigned long ima_hash_key(u8 *digest) } /* LIM API function definitions */ -int ima_must_appraise_or_measure(struct inode *inode, int mask, int function); +int ima_get_action(struct inode *inode, int mask, int function); int ima_must_measure(struct inode *inode, int mask, int function); int ima_collect_measurement(struct integrity_iint_cache *iint, struct file *file); diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index 33d46859753a..f0d60e754b3e 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -97,7 +97,7 @@ err_out: } /** - * ima_must_appraise_or_measure - appraise & measure decision based on policy. + * ima_get_action - appraise & measure decision based on policy. * @inode: pointer to inode to measure * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXECUTE) * @function: calling function (FILE_CHECK, BPRM_CHECK, FILE_MMAP) @@ -112,7 +112,7 @@ err_out: * Returns IMA_MEASURE, IMA_APPRAISE mask. * */ -int ima_must_appraise_or_measure(struct inode *inode, int mask, int function) +int ima_get_action(struct inode *inode, int mask, int function) { int flags = IMA_MEASURE | IMA_APPRAISE; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index df6521296051..60b047e96f4e 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -158,7 +158,7 @@ static int process_measurement(struct file *file, const unsigned char *filename, /* Determine if in appraise/measurement policy, * returns IMA_MEASURE, IMA_APPRAISE bitmask. */ - action = ima_must_appraise_or_measure(inode, mask, function); + action = ima_get_action(inode, mask, function); if (!action) return 0; -- cgit v1.2.3 From 45e2472e67bf66f794d507b52e82af92e0614e49 Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Wed, 12 Sep 2012 20:51:32 +0300 Subject: ima: generic IMA action flag handling Make the IMA action flag handling generic in order to support additional new actions, without requiring changes to the base implementation. New actions, like audit logging, will only need to modify the define statements. Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- security/integrity/ima/ima_appraise.c | 2 +- security/integrity/ima/ima_main.c | 4 ++-- security/integrity/ima/ima_policy.c | 21 +++++++++++---------- security/integrity/integrity.h | 18 ++++++++++++------ 4 files changed, 26 insertions(+), 19 deletions(-) (limited to 'security') diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 4cdf36ad884a..0aa43bde441c 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -232,7 +232,7 @@ static void ima_reset_appraise_flags(struct inode *inode) if (!iint) return; - iint->flags &= ~(IMA_COLLECTED | IMA_APPRAISED | IMA_MEASURED); + iint->flags &= ~IMA_DONE_MASK; return; } diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 60b047e96f4e..5da08b75d367 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -117,7 +117,7 @@ static void ima_check_last_writer(struct integrity_iint_cache *iint, mutex_lock(&inode->i_mutex); if (atomic_read(&inode->i_writecount) == 1 && iint->version != inode->i_version) { - iint->flags &= ~(IMA_COLLECTED | IMA_APPRAISED | IMA_MEASURED); + iint->flags &= ~IMA_DONE_MASK; if (iint->flags & IMA_APPRAISE) ima_update_xattr(iint, file); } @@ -173,7 +173,7 @@ static int process_measurement(struct file *file, const unsigned char *filename, /* Determine if already appraised/measured based on bitmask * (IMA_MEASURE, IMA_MEASURED, IMA_APPRAISE, IMA_APPRAISED) */ iint->flags |= action; - action &= ~((iint->flags & (IMA_MEASURED | IMA_APPRAISED)) >> 1); + action &= ~((iint->flags & IMA_DONE_MASK) >> 1); /* Nothing to do, just return existing appraised status */ if (!action) { diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 0d6d60b4ba6f..f46f685a1711 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -26,13 +26,11 @@ #define IMA_UID 0x0008 #define IMA_FOWNER 0x0010 -#define UNKNOWN 0 -#define MEASURE 1 /* same as IMA_MEASURE */ -#define DONT_MEASURE 2 -#define MEASURE_MASK 3 -#define APPRAISE 4 /* same as IMA_APPRAISE */ -#define DONT_APPRAISE 8 -#define APPRAISE_MASK 12 +#define UNKNOWN 0 +#define MEASURE 0x0001 /* same as IMA_MEASURE */ +#define DONT_MEASURE 0x0002 +#define APPRAISE 0x0004 /* same as IMA_APPRAISE */ +#define DONT_APPRAISE 0x0008 #define MAX_LSM_RULES 6 enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE, @@ -209,9 +207,12 @@ int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask, if (!ima_match_rules(entry, inode, func, mask)) continue; - action |= (entry->action & (IMA_APPRAISE | IMA_MEASURE)); - actmask &= (entry->action & APPRAISE_MASK) ? - ~APPRAISE_MASK : ~MEASURE_MASK; + action |= entry->action & IMA_DO_MASK; + if (entry->action & IMA_DO_MASK) + actmask &= ~(entry->action | entry->action << 1); + else + actmask &= ~(entry->action | entry->action >> 1); + if (!actmask) break; } diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 4eec1b14193e..564ba7db5f6a 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -15,13 +15,19 @@ #include #include +/* iint action cache flags */ +#define IMA_MEASURE 0x0001 +#define IMA_MEASURED 0x0002 +#define IMA_APPRAISE 0x0004 +#define IMA_APPRAISED 0x0008 +/*#define IMA_COLLECT 0x0010 do not use this flag */ +#define IMA_COLLECTED 0x0020 + /* iint cache flags */ -#define IMA_MEASURE 0x01 -#define IMA_MEASURED 0x02 -#define IMA_APPRAISE 0x04 -#define IMA_APPRAISED 0x08 -#define IMA_COLLECTED 0x10 -#define IMA_DIGSIG 0x20 +#define IMA_DIGSIG 0x0100 + +#define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE) +#define IMA_DONE_MASK (IMA_MEASURED | IMA_APPRAISED | IMA_COLLECTED) enum evm_ima_xattr_type { IMA_XATTR_DIGEST = 0x01, -- cgit v1.2.3 From e7c568e0fd0cf6d9c8ab8ea537ba8f3a3ae7c3d8 Mon Sep 17 00:00:00 2001 From: Peter Moody Date: Thu, 14 Jun 2012 10:04:36 -0700 Subject: ima: audit log hashes This adds an 'audit' policy action which audit logs file measurements. Changelog v6: - use new action flag handling (Dmitry Kasatkin). - removed whitespace (Mimi) Changelog v5: - use audit_log_untrustedstring. Changelog v4: - cleanup digest -> hash conversion. - use filename rather than d_path in ima_audit_measurement. Changelog v3: - Use newly exported audit_log_task_info for logging pid/ppid/uid/etc. - Update the ima_policy ABI documentation. Changelog v2: - Use 'audit' action rather than 'measure_and_audit' to permit auditing in the absence of measuring.. Changelog v1: - Initial posting. Signed-off-by: Peter Moody Signed-off-by: Mimi Zohar --- Documentation/ABI/testing/ima_policy | 2 +- security/integrity/ima/ima.h | 2 ++ security/integrity/ima/ima_api.c | 32 +++++++++++++++++++++++++++++++- security/integrity/ima/ima_main.c | 9 ++++++--- security/integrity/ima/ima_policy.c | 11 +++++++++++ security/integrity/integrity.h | 7 +++++-- 6 files changed, 56 insertions(+), 7 deletions(-) (limited to 'security') diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index dcff82205477..986946613542 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -17,7 +17,7 @@ Description: rule format: action [condition ...] - action: measure | dont_measure | appraise | dont_appraise + action: measure | dont_measure | appraise | dont_appraise | audit condition:= base | lsm base: [[func=] [mask=] [fsmagic=] [uid=] [fowner]] lsm: [[subj_user=] [subj_role=] [subj_type=] diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 48aa0d46d3e7..8180adde10b7 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -114,6 +114,8 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, struct file *file); void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, const unsigned char *filename); +void ima_audit_measurement(struct integrity_iint_cache *iint, + const unsigned char *filename); int ima_store_template(struct ima_template_entry *entry, int violation, struct inode *inode); void ima_template_show(struct seq_file *m, void *e, enum ima_show_type show); diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index f0d60e754b3e..b356884fb3ef 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -114,7 +114,7 @@ err_out: */ int ima_get_action(struct inode *inode, int mask, int function) { - int flags = IMA_MEASURE | IMA_APPRAISE; + int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE; if (!ima_appraise) flags &= ~IMA_APPRAISE; @@ -207,3 +207,33 @@ void ima_store_measurement(struct integrity_iint_cache *iint, if (result < 0) kfree(entry); } + +void ima_audit_measurement(struct integrity_iint_cache *iint, + const unsigned char *filename) +{ + struct audit_buffer *ab; + char hash[(IMA_DIGEST_SIZE * 2) + 1]; + int i; + + if (iint->flags & IMA_AUDITED) + return; + + for (i = 0; i < IMA_DIGEST_SIZE; i++) + hex_byte_pack(hash + (i * 2), iint->ima_xattr.digest[i]); + hash[i * 2] = '\0'; + + ab = audit_log_start(current->audit_context, GFP_KERNEL, + AUDIT_INTEGRITY_RULE); + if (!ab) + return; + + audit_log_format(ab, "file="); + audit_log_untrustedstring(ab, filename); + audit_log_format(ab, " hash="); + audit_log_untrustedstring(ab, hash); + + audit_log_task_info(ab, current); + audit_log_end(ab); + + iint->flags |= IMA_AUDITED; +} diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 5da08b75d367..73c9a268253e 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -156,8 +156,8 @@ static int process_measurement(struct file *file, const unsigned char *filename, if (!ima_initialized || !S_ISREG(inode->i_mode)) return 0; - /* Determine if in appraise/measurement policy, - * returns IMA_MEASURE, IMA_APPRAISE bitmask. */ + /* Determine if in appraise/audit/measurement policy, + * returns IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT bitmask. */ action = ima_get_action(inode, mask, function); if (!action) return 0; @@ -171,7 +171,8 @@ static int process_measurement(struct file *file, const unsigned char *filename, goto out; /* Determine if already appraised/measured based on bitmask - * (IMA_MEASURE, IMA_MEASURED, IMA_APPRAISE, IMA_APPRAISED) */ + * (IMA_MEASURE, IMA_MEASURED, IMA_APPRAISE, IMA_APPRAISED, + * IMA_AUDIT, IMA_AUDITED) */ iint->flags |= action; action &= ~((iint->flags & IMA_DONE_MASK) >> 1); @@ -202,6 +203,8 @@ static int process_measurement(struct file *file, const unsigned char *filename, if (action & IMA_APPRAISE) rc = ima_appraise_measurement(iint, file, !pathname ? filename : pathname); + if (action & IMA_AUDIT) + ima_audit_measurement(iint, !pathname ? filename : pathname); kfree(pathbuf); out: mutex_unlock(&inode->i_mutex); diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index f46f685a1711..cda903131dbf 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -31,6 +31,7 @@ #define DONT_MEASURE 0x0002 #define APPRAISE 0x0004 /* same as IMA_APPRAISE */ #define DONT_APPRAISE 0x0008 +#define AUDIT 0x0040 #define MAX_LSM_RULES 6 enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE, @@ -277,6 +278,7 @@ enum { Opt_err = -1, Opt_measure = 1, Opt_dont_measure, Opt_appraise, Opt_dont_appraise, + Opt_audit, Opt_obj_user, Opt_obj_role, Opt_obj_type, Opt_subj_user, Opt_subj_role, Opt_subj_type, Opt_func, Opt_mask, Opt_fsmagic, Opt_uid, Opt_fowner @@ -287,6 +289,7 @@ static match_table_t policy_tokens = { {Opt_dont_measure, "dont_measure"}, {Opt_appraise, "appraise"}, {Opt_dont_appraise, "dont_appraise"}, + {Opt_audit, "audit"}, {Opt_obj_user, "obj_user=%s"}, {Opt_obj_role, "obj_role=%s"}, {Opt_obj_type, "obj_type=%s"}, @@ -379,6 +382,14 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) entry->action = DONT_APPRAISE; break; + case Opt_audit: + ima_log_string(ab, "action", "audit"); + + if (entry->action != UNKNOWN) + result = -EINVAL; + + entry->action = AUDIT; + break; case Opt_func: ima_log_string(ab, "func", args[0].from); diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 564ba7db5f6a..403ba319a06a 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -22,12 +22,15 @@ #define IMA_APPRAISED 0x0008 /*#define IMA_COLLECT 0x0010 do not use this flag */ #define IMA_COLLECTED 0x0020 +#define IMA_AUDIT 0x0040 +#define IMA_AUDITED 0x0080 /* iint cache flags */ #define IMA_DIGSIG 0x0100 -#define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE) -#define IMA_DONE_MASK (IMA_MEASURED | IMA_APPRAISED | IMA_COLLECTED) +#define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT) +#define IMA_DONE_MASK (IMA_MEASURED | IMA_APPRAISED | IMA_AUDITED \ + | IMA_COLLECTED) enum evm_ima_xattr_type { IMA_XATTR_DIGEST = 0x01, -- cgit v1.2.3 From c00bedb368ae02a066aed8a888afc286c1df2e60 Mon Sep 17 00:00:00 2001 From: Casey Schaufler Date: Thu, 9 Aug 2012 17:46:38 -0700 Subject: Smack: remove task_wait() hook. On 12/20/2011 11:20 PM, Jarkko Sakkinen wrote: > Allow SIGCHLD to be passed to child process without > explicit policy. This will help to keep the access > control policy simple and easily maintainable with > complex applications that require use of multiple > security contexts. It will also help to keep them > as isolated as possible. > > Signed-off-by: Jarkko Sakkinen I have a slightly different version that applies to the current smack-next tree. Allow SIGCHLD to be passed to child process without explicit policy. This will help to keep the access control policy simple and easily maintainable with complex applications that require use of multiple security contexts. It will also help to keep them as isolated as possible. Signed-off-by: Casey Schaufler security/smack/smack_lsm.c | 37 ++++++++----------------------------- 1 files changed, 8 insertions(+), 29 deletions(-) --- security/smack/smack_lsm.c | 37 ++++++++----------------------------- 1 file changed, 8 insertions(+), 29 deletions(-) (limited to 'security') diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 8221514cc997..ce9273a18165 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -1691,40 +1691,19 @@ static int smack_task_kill(struct task_struct *p, struct siginfo *info, * smack_task_wait - Smack access check for waiting * @p: task to wait for * - * Returns 0 if current can wait for p, error code otherwise + * Returns 0 */ static int smack_task_wait(struct task_struct *p) { - struct smk_audit_info ad; - char *sp = smk_of_current(); - char *tsp = smk_of_forked(task_security(p)); - int rc; - - /* we don't log here, we can be overriden */ - rc = smk_access(tsp, sp, MAY_WRITE, NULL); - if (rc == 0) - goto out_log; - /* - * Allow the operation to succeed if either task - * has privilege to perform operations that might - * account for the smack labels having gotten to - * be different in the first place. - * - * This breaks the strict subject/object access - * control ideal, taking the object's privilege - * state into account in the decision as well as - * the smack value. + * Allow the operation to succeed. + * Zombies are bad. + * In userless environments (e.g. phones) programs + * get marked with SMACK64EXEC and even if the parent + * and child shouldn't be talking the parent still + * may expect to know when the child exits. */ - if (smack_privileged(CAP_MAC_OVERRIDE) || - has_capability(p, CAP_MAC_OVERRIDE)) - rc = 0; - /* we log only if we didn't get overriden */ - out_log: - smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); - smk_ad_setfield_u_tsk(&ad, p); - smack_log(tsp, sp, MAY_WRITE, rc, &ad); - return rc; + return 0; } /** -- cgit v1.2.3 From 449543b0436a9146b855aad39eab76ae4853e88d Mon Sep 17 00:00:00 2001 From: Rafal Krypa Date: Wed, 11 Jul 2012 17:49:30 +0200 Subject: Smack: implement revoking all rules for a subject label Add /smack/revoke-subject special file. Writing a SMACK label to this file will set the access to '-' for all access rules with that subject label. Targeted for git://git.gitorious.org/smack-next/kernel.git Signed-off-by: Rafal Krypa --- Documentation/security/Smack.txt | 3 ++ security/smack/smackfs.c | 75 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 78 insertions(+) (limited to 'security') diff --git a/Documentation/security/Smack.txt b/Documentation/security/Smack.txt index a416479b8a1c..e68536d85680 100644 --- a/Documentation/security/Smack.txt +++ b/Documentation/security/Smack.txt @@ -194,6 +194,9 @@ onlycap these capabilities are effective at for processes with any label. The value is set by writing the desired label to the file or cleared by writing "-" to the file. +revoke-subject + Writing a Smack label here sets the access to '-' for all access + rules with that subject label. You can add access rules in /etc/smack/accesses. They take the form: diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index b1b768e4049a..99929a50093a 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -49,6 +49,7 @@ enum smk_inos { SMK_LOAD_SELF2 = 15, /* load task specific rules with long labels */ SMK_ACCESS2 = 16, /* make an access check with long labels */ SMK_CIPSO2 = 17, /* load long label -> CIPSO mapping */ + SMK_REVOKE_SUBJ = 18, /* set rules with subject label to '-' */ }; /* @@ -1991,6 +1992,77 @@ static const struct file_operations smk_access2_ops = { .llseek = generic_file_llseek, }; +/** + * smk_write_revoke_subj - write() for /smack/revoke-subject + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_write_revoke_subj(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char *data = NULL; + const char *cp = NULL; + struct smack_known *skp; + struct smack_rule *sp; + struct list_head *rule_list; + struct mutex *rule_lock; + int rc = count; + + if (*ppos != 0) + return -EINVAL; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count == 0 || count > SMK_LONGLABEL) + return -EINVAL; + + data = kzalloc(count, GFP_KERNEL); + if (data == NULL) + return -ENOMEM; + + if (copy_from_user(data, buf, count) != 0) { + rc = -EFAULT; + goto free_out; + } + + cp = smk_parse_smack(data, count); + if (cp == NULL) { + rc = -EINVAL; + goto free_out; + } + + skp = smk_find_entry(cp); + if (skp == NULL) { + rc = -EINVAL; + goto free_out; + } + + rule_list = &skp->smk_rules; + rule_lock = &skp->smk_rules_lock; + + mutex_lock(rule_lock); + + list_for_each_entry_rcu(sp, rule_list, list) + sp->smk_access = 0; + + mutex_unlock(rule_lock); + +free_out: + kfree(data); + kfree(cp); + return rc; +} + +static const struct file_operations smk_revoke_subj_ops = { + .write = smk_write_revoke_subj, + .read = simple_transaction_read, + .release = simple_transaction_release, + .llseek = generic_file_llseek, +}; + /** * smk_fill_super - fill the /smackfs superblock * @sb: the empty superblock @@ -2037,6 +2109,9 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent) "access2", &smk_access2_ops, S_IRUGO|S_IWUGO}, [SMK_CIPSO2] = { "cipso2", &smk_cipso2_ops, S_IRUGO|S_IWUSR}, + [SMK_REVOKE_SUBJ] = { + "revoke-subject", &smk_revoke_subj_ops, + S_IRUGO|S_IWUSR}, /* last one */ {""} }; -- cgit v1.2.3 From 46a2f3b9e99353cc63e15563e8abee71162330f7 Mon Sep 17 00:00:00 2001 From: Casey Schaufler Date: Wed, 22 Aug 2012 11:44:03 -0700 Subject: Smack: setprocattr memory leak fix The data structure allocations being done in prepare_creds are duplicated in smack_setprocattr. This results in the structure allocated in prepare_creds being orphaned and never freed. The duplicate code is removed from smack_setprocattr. Targeted for git://git.gitorious.org/smack-next/kernel.git Signed-off-by: Casey Schaufler --- security/smack/smack_lsm.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-) (limited to 'security') diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index ce9273a18165..2874c7316783 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -2684,9 +2684,7 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value) static int smack_setprocattr(struct task_struct *p, char *name, void *value, size_t size) { - int rc; struct task_smack *tsp; - struct task_smack *oldtsp; struct cred *new; char *newsmack; @@ -2716,21 +2714,13 @@ static int smack_setprocattr(struct task_struct *p, char *name, if (newsmack == smack_known_web.smk_known) return -EPERM; - oldtsp = p->cred->security; new = prepare_creds(); if (new == NULL) return -ENOMEM; - tsp = new_task_smack(newsmack, oldtsp->smk_forked, GFP_KERNEL); - if (tsp == NULL) { - kfree(new); - return -ENOMEM; - } - rc = smk_copy_rules(&tsp->smk_rules, &oldtsp->smk_rules, GFP_KERNEL); - if (rc != 0) - return rc; + tsp = new->security; + tsp->smk_task = newsmack; - new->security = tsp; commit_creds(new); return size; } -- cgit v1.2.3 From 0a72ba7aff26fb6e918cee6d2bbfd289069f10ae Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Wed, 19 Sep 2012 15:32:49 +0300 Subject: ima: change flags container data type IMA audit hashes patches introduced new IMA flags and required space went beyond 8 bits. Currently the only flag is IMA_DIGSIG. This patch use 16 bit short instead of 8 bit char. Without this fix IMA signature will be replaced with hash, which should not happen. Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- security/integrity/integrity.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'security') diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 403ba319a06a..e9db763a875e 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -48,7 +48,7 @@ struct integrity_iint_cache { struct rb_node rb_node; /* rooted in integrity_iint_tree */ struct inode *inode; /* back pointer to inode in question */ u64 version; /* track inode changes */ - unsigned char flags; + unsigned short flags; struct evm_ima_xattr_data ima_xattr; enum integrity_status ima_status; enum integrity_status evm_status; -- cgit v1.2.3