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* lsk-44/linux-linaro-lsk-v4.4:
Linux 4.4.3
modules: fix modparam async_probe request
module: wrapper for symbol name.
itimers: Handle relative timers with CONFIG_TIME_LOW_RES proper
posix-timers: Handle relative timers with CONFIG_TIME_LOW_RES proper
timerfd: Handle relative timers with CONFIG_TIME_LOW_RES proper
prctl: take mmap sem for writing to protect against others
xfs: log mount failures don't wait for buffers to be released
Revert "xfs: clear PF_NOFREEZE for xfsaild kthread"
xfs: inode recovery readahead can race with inode buffer creation
libxfs: pack the agfl header structure so XFS_AGFL_SIZE is correct
ovl: setattr: check permissions before copy-up
ovl: root: copy attr
ovl: check dentry positiveness in ovl_cleanup_whiteouts()
ovl: use a minimal buffer in ovl_copy_xattr
ovl: allow zero size xattr
futex: Drop refcount if requeue_pi() acquired the rtmutex
devm_memremap_release(): fix memremap'd addr handling
ipc/shm: handle removed segments gracefully in shm_mmap()
intel_scu_ipcutil: underflow in scu_reg_access()
mm,thp: khugepaged: call pte flush at the time of collapse
dump_stack: avoid potential deadlocks
radix-tree: fix oops after radix_tree_iter_retry
drivers/hwspinlock: fix race between radix tree insertion and lookup
radix-tree: fix race in gang lookup
MAINTAINERS: return arch/sh to maintained state, with new maintainers
memcg: only free spare array when readers are done
numa: fix /proc/<pid>/numa_maps for hugetlbfs on s390
fs/hugetlbfs/inode.c: fix bugs in hugetlb_vmtruncate_list()
scripts/bloat-o-meter: fix python3 syntax error
dma-debug: switch check from _text to _stext
m32r: fix m32104ut_defconfig build fail
xhci: Fix list corruption in urb dequeue at host removal
Revert "xhci: don't finish a TD if we get a short-transfer event mid TD"
iommu/vt-d: Clear PPR bit to ensure we get more page request interrupts
iommu/vt-d: Fix 64-bit accesses to 32-bit DMAR_GSTS_REG
iommu/vt-d: Fix mm refcounting to hold mm_count not mm_users
iommu/amd: Correct the wrong setting of alias DTE in do_attach
iommu/vt-d: Don't skip PCI devices when disabling IOTLB
Input: vmmouse - fix absolute device registration
string_helpers: fix precision loss for some inputs
Input: i8042 - add Fujitsu Lifebook U745 to the nomux list
Input: elantech - mark protocols v2 and v3 as semi-mt
mm: fix regression in remap_file_pages() emulation
mm: replace vma_lock_anon_vma with anon_vma_lock_read/write
mm: fix mlock accouting
libnvdimm: fix namespace object confusion in is_uuid_busy()
mm: soft-offline: check return value in second __get_any_page() call
perf kvm record/report: 'unprocessable sample' error while recording/reporting guest data
KVM: PPC: Fix ONE_REG AltiVec support
KVM: PPC: Fix emulation of H_SET_DABR/X on POWER8
KVM: arm/arm64: Fix reference to uninitialised VGIC
arm64: dma-mapping: fix handling of devices registered before arch_initcall
ARM: OMAP2+: Fix ppa_zero_params and ppa_por_params for rodata
ARM: OMAP2+: Fix save_secure_ram_context for rodata
ARM: OMAP2+: Fix l2dis_3630 for rodata
ARM: OMAP2+: Fix l2_inv_api_params for rodata
ARM: OMAP2+: Fix wait_dll_lock_timed for rodata
ARM: dts: at91: sama5d4ek: add phy address and IRQ for macb0
ARM: dts: at91: sama5d4 xplained: fix phy0 IRQ type
ARM: dts: at91: sama5d4: fix instance id of DBGU
ARM: dts: at91: sama5d4 xplained: properly mux phy interrupt
ARM: dts: omap5-board-common: enable rtc and charging of backup battery
ARM: dts: Fix omap5 PMIC control lines for RTC writes
ARM: dts: Fix wl12xx missing clocks that cause hangs
ARM: nomadik: fix up SD/MMC DT settings
ARM: 8517/1: ICST: avoid arithmetic overflow in icst_hz()
ARM: 8519/1: ICST: try other dividends than 1
arm64: mm: avoid calling apply_to_page_range on empty range
ARM: mvebu: remove duplicated regulator definition in Armada 388 GP
powerpc/ioda: Set "read" permission when "write" is set
powerpc/powernv: Fix stale PE primary bus
powerpc/eeh: Fix stale cached primary bus
powerpc/eeh: Fix PE location code
SUNRPC: Fixup socket wait for memory
udf: Check output buffer length when converting name to CS0
udf: Prevent buffer overrun with multi-byte characters
udf: limit the maximum number of indirect extents in a row
pNFS/flexfiles: Fix an XDR encoding bug in layoutreturn
nfs: Fix race in __update_open_stateid()
pNFS/flexfiles: Fix an Oopsable typo in ff_mirror_match_fh()
NFS: Fix attribute cache revalidation
cifs: fix erroneous return value
cifs_dbg() outputs an uninitialized buffer in cifs_readdir()
cifs: fix race between call_async() and reconnect()
cifs: Ratelimit kernel log messages
iio: inkern: fix a NULL dereference on error
iio: pressure: mpl115: fix temperature offset sign
iio: light: acpi-als: Report data as processed
iio: dac: mcp4725: set iio name property in sysfs
iio: add IIO_TRIGGER dependency to STK8BA50
iio: add HAS_IOMEM dependency to VF610_ADC
iio-light: Use a signed return type for ltr501_match_samp_freq()
iio:adc:ti_am335x_adc Fix buffered mode by identifying as software buffer.
iio: adis_buffer: Fix out-of-bounds memory access
scsi: fix soft lockup in scsi_remove_target() on module removal
SCSI: Add Marvell Console to VPD blacklist
scsi_dh_rdac: always retry MODE SELECT on command lock violation
drivers/scsi/sg.c: mark VMA as VM_IO to prevent migration
SCSI: fix crashes in sd and sr runtime PM
iscsi-target: Fix potential dead-lock during node acl delete
scsi: add Synology to 1024 sector blacklist
klist: fix starting point removed bug in klist iterators
tracepoints: Do not trace when cpu is offline
tracing: Fix freak link error caused by branch tracer
perf tools: tracepoint_error() can receive e=NULL, robustify it
tools lib traceevent: Fix output of %llu for 64 bit values read on 32 bit machines
ptrace: use fsuid, fsgid, effective creds for fs access checks
Btrfs: fix direct IO requests not reporting IO error to user space
Btrfs: fix hang on extent buffer lock caused by the inode_paths ioctl
Btrfs: fix page reading in extent_same ioctl leading to csum errors
Btrfs: fix invalid page accesses in extent_same (dedup) ioctl
btrfs: properly set the termination value of ctx->pos in readdir
Revert "btrfs: clear PF_NOFREEZE in cleaner_kthread()"
Btrfs: fix fitrim discarding device area reserved for boot loader's use
btrfs: handle invalid num_stripes in sys_array
ext4: don't read blocks from disk after extents being swapped
ext4: fix potential integer overflow
ext4: fix scheduling in atomic on group checksum failure
serial: omap: Prevent DoS using unprivileged ioctl(TIOCSRS485)
serial: 8250_pci: Add Intel Broadwell ports
tty: Add support for PCIe WCH382 2S multi-IO card
pty: make sure super_block is still valid in final /dev/tty close
pty: fix possible use after free of tty->driver_data
staging/speakup: Use tty_ldisc_ref() for paste kworker
phy: twl4030-usb: Fix unbalanced pm_runtime_enable on module reload
phy: twl4030-usb: Relase usb phy on unload
ALSA: seq: Fix double port list deletion
ALSA: seq: Fix leak of pool buffer at concurrent writes
ALSA: pcm: Fix rwsem deadlock for non-atomic PCM stream
ALSA: hda - Cancel probe work instead of flush at remove
x86/mm: Fix vmalloc_fault() to handle large pages properly
x86/uaccess/64: Handle the caching of 4-byte nocache copies properly in __copy_user_nocache()
x86/uaccess/64: Make the __copy_user_nocache() assembly code more readable
x86/mm/pat: Avoid truncation when converting cpa->numpages to address
x86/mm: Fix types used in pgprot cacheability flags translations
Linux 4.4.2
HID: multitouch: fix input mode switching on some Elan panels
mm, vmstat: fix wrong WQ sleep when memory reclaim doesn't make any progress
zsmalloc: fix migrate_zspage-zs_free race condition
zram: don't call idr_remove() from zram_remove()
zram: try vmalloc() after kmalloc()
zram/zcomp: use GFP_NOIO to allocate streams
rtlwifi: rtl8821ae: Fix 5G failure when EEPROM is incorrectly encoded
rtlwifi: rtl8821ae: Fix errors in parameter initialization
crypto: marvell/cesa - fix test in mv_cesa_dev_dma_init()
crypto: atmel-sha - remove calls of clk_prepare() from atomic contexts
crypto: atmel-sha - fix atmel_sha_remove()
crypto: algif_skcipher - Do not set MAY_BACKLOG on the async path
crypto: algif_skcipher - Do not dereference ctx without socket lock
crypto: algif_skcipher - Do not assume that req is unchanged
crypto: user - lock crypto_alg_list on alg dump
EVM: Use crypto_memneq() for digest comparisons
crypto: algif_hash - wait for crypto_ahash_init() to complete
crypto: shash - Fix has_key setting
crypto: chacha20-ssse3 - Align stack pointer to 64 bytes
crypto: caam - make write transactions bufferable on PPC platforms
crypto: algif_skcipher - sendmsg SG marking is off by one
crypto: algif_skcipher - Load TX SG list after waiting
crypto: crc32c - Fix crc32c soft dependency
crypto: algif_skcipher - Fix race condition in skcipher_check_key
crypto: algif_hash - Fix race condition in hash_check_key
crypto: af_alg - Forbid bind(2) when nokey child sockets are present
crypto: algif_skcipher - Remove custom release parent function
crypto: algif_hash - Remove custom release parent function
crypto: af_alg - Allow af_af_alg_release_parent to be called on nokey path
ahci: Intel DNV device IDs SATA
libata: disable forced PORTS_IMPL for >= AHCI 1.3
crypto: algif_skcipher - Add key check exception for cipher_null
crypto: skcipher - Add crypto_skcipher_has_setkey
crypto: algif_hash - Require setkey before accept(2)
crypto: hash - Add crypto_ahash_has_setkey
crypto: algif_skcipher - Add nokey compatibility path
crypto: af_alg - Add nokey compatibility path
crypto: af_alg - Fix socket double-free when accept fails
crypto: af_alg - Disallow bind/setkey/... after accept(2)
crypto: algif_skcipher - Require setkey before accept(2)
sched: Fix crash in sched_init_numa()
ext4 crypto: add missing locking for keyring_key access
iommu/io-pgtable-arm: Ensure we free the final level on teardown
tty: Fix unsafe ldisc reference via ioctl(TIOCGETD)
tty: Retry failed reopen if tty teardown in-progress
tty: Wait interruptibly for tty lock on reopen
n_tty: Fix unsafe reference to "other" ldisc
usb: xhci: apply XHCI_PME_STUCK_QUIRK to Intel Broxton-M platforms
usb: xhci: handle both SSIC ports in PME stuck quirk
usb: phy: msm: fix error handling in probe.
usb: cdc-acm: send zero packet for intel 7260 modem
usb: cdc-acm: handle unlinked urb in acm read callback
USB: option: fix Cinterion AHxx enumeration
USB: serial: option: Adding support for Telit LE922
USB: cp210x: add ID for IAI USB to RS485 adaptor
USB: serial: ftdi_sio: add support for Yaesu SCU-18 cable
usb: hub: do not clear BOS field during reset device
USB: visor: fix null-deref at probe
USB: serial: visor: fix crash on detecting device without write_urbs
ASoC: rt5645: fix the shift bit of IN1 boost
saa7134-alsa: Only frees registered sound cards
ALSA: dummy: Implement timer backend switching more safely
ALSA: hda - Fix bad dereference of jack object
ALSA: hda - Fix speaker output from VAIO AiO machines
Revert "ALSA: hda - Fix noise on Gigabyte Z170X mobo"
ALSA: hda - Fix static checker warning in patch_hdmi.c
ALSA: hda - Add fixup for Mac Mini 7,1 model
ALSA: timer: Fix race between stop and interrupt
ALSA: timer: Fix wrong instance passed to slave callbacks
ALSA: timer: Fix race at concurrent reads
ALSA: timer: Fix link corruption due to double start or stop
ALSA: timer: Fix leftover link at closing
ALSA: timer: Code cleanup
ALSA: seq: Fix lockdep warnings due to double mutex locks
ALSA: seq: Fix race at closing in virmidi driver
ALSA: seq: Fix yet another races among ALSA timer accesses
ASoC: dpcm: fix the BE state on hw_free
ALSA: pcm: Fix potential deadlock in OSS emulation
ALSA: hda/realtek - Support Dell headset mode for ALC225
ALSA: hda/realtek - Support headset mode for ALC225
ALSA: hda/realtek - New codec support of ALC225
ALSA: rawmidi: Fix race at copying & updating the position
ALSA: rawmidi: Remove kernel WARNING for NULL user-space buffer check
ALSA: rawmidi: Make snd_rawmidi_transmit() race-free
ALSA: seq: Degrade the error message for too many opens
ALSA: seq: Fix incorrect sanity check at snd_seq_oss_synth_cleanup()
ALSA: dummy: Disable switching timer backend via sysfs
ALSA: compress: Disable GET_CODEC_CAPS ioctl for some architectures
ALSA: hda - disable dynamic clock gating on Broxton before reset
ALSA: Add missing dependency on CONFIG_SND_TIMER
ALSA: bebob: Use a signed return type for get_formation_index
ALSA: usb-audio: avoid freeing umidi object twice
ALSA: usb-audio: Add native DSD support for PS Audio NuWave DAC
ALSA: usb-audio: Fix OPPO HA-1 vendor ID
ALSA: usb-audio: Add quirk for Microsoft LifeCam HD-6000
ALSA: usb-audio: Fix TEAC UD-501/UD-503/NT-503 usb delay
hrtimer: Handle remaining time proper for TIME_LOW_RES
md/raid: only permit hot-add of compatible integrity profiles
media: i2c: Don't export ir-kbd-i2c module alias
parisc: Fix __ARCH_SI_PREAMBLE_SIZE
parisc: Protect huge page pte changes with spinlocks
printk: do cond_resched() between lines while outputting to consoles
tracing/stacktrace: Show entire trace if passed in function not found
tracing: Fix stacktrace skip depth in trace_buffer_unlock_commit_regs()
PCI: Fix minimum allocation address overwrite
PCI: host: Mark PCIe/PCI (MSI) IRQ cascade handlers as IRQF_NO_THREAD
mtd: nand: assign reasonable default name for NAND drivers
wlcore/wl12xx: spi: fix NULL pointer dereference (Oops)
wlcore/wl12xx: spi: fix oops on firmware load
ocfs2/dlm: clear refmap bit of recovery lock while doing local recovery cleanup
ocfs2/dlm: ignore cleaning the migration mle that is inuse
ALSA: hda - Implement loopback control switch for Realtek and other codecs
block: fix bio splitting on max sectors
base/platform: Fix platform drivers with no probe callback
HID: usbhid: fix recursive deadlock
ocfs2: NFS hangs in __ocfs2_cluster_lock due to race with ocfs2_unblock_lock
block: split bios to max possible length
NFSv4.1/pnfs: Fixup an lo->plh_block_lgets imbalance in layoutreturn
crypto: sun4i-ss - add missing statesize
Linux 4.4.1
arm64: kernel: fix architected PMU registers unconditional access
arm64: kernel: enforce pmuserenr_el0 initialization and restore
arm64: mm: ensure that the zero page is visible to the page table walker
arm64: Clear out any singlestep state on a ptrace detach operation
powerpc/module: Handle R_PPC64_ENTRY relocations
scripts/recordmcount.pl: support data in text section on powerpc
powerpc: Make {cmp}xchg* and their atomic_ versions fully ordered
powerpc: Make value-returning atomics fully ordered
powerpc/tm: Check for already reclaimed tasks
batman-adv: Drop immediate orig_node free function
batman-adv: Drop immediate batadv_hard_iface free function
batman-adv: Drop immediate neigh_ifinfo free function
batman-adv: Drop immediate batadv_neigh_node free function
batman-adv: Drop immediate batadv_orig_ifinfo free function
batman-adv: Avoid recursive call_rcu for batadv_nc_node
batman-adv: Avoid recursive call_rcu for batadv_bla_claim
team: Replace rcu_read_lock with a mutex in team_vlan_rx_kill_vid
net/mlx5_core: Fix trimming down IRQ number
bridge: fix lockdep addr_list_lock false positive splat
ipv6: update skb->csum when CE mark is propagated
net: bpf: reject invalid shifts
phonet: properly unshare skbs in phonet_rcv()
dwc_eth_qos: Fix dma address for multi-fragment skbs
bonding: Prevent IPv6 link local address on enslaved devices
net: preserve IP control block during GSO segmentation
udp: disallow UFO for sockets with SO_NO_CHECK option
net: pktgen: fix null ptr deref in skb allocation
sched,cls_flower: set key address type when present
tcp_yeah: don't set ssthresh below 2
ipv6: tcp: add rcu locking in tcp_v6_send_synack()
net: sctp: prevent writes to cookie_hmac_alg from accessing invalid memory
vxlan: fix test which detect duplicate vxlan iface
unix: properly account for FDs passed over unix sockets
xhci: refuse loading if nousb is used
usb: core: lpm: fix usb3_hardware_lpm sysfs node
USB: cp210x: add ID for ELV Marble Sound Board 1
rtlwifi: fix memory leak for USB device
ASoC: compress: Fix compress device direction check
ASoC: wm5110: Fix PGA clear when disabling DRE
ALSA: timer: Handle disconnection more safely
ALSA: hda - Flush the pending probe work at remove
ALSA: hda - Fix missing module loading with model=generic option
ALSA: hda - Fix bass pin fixup for ASUS N550JX
ALSA: control: Avoid kernel warnings from tlv ioctl with numid 0
ALSA: hrtimer: Fix stall by hrtimer_cancel()
ALSA: pcm: Fix snd_pcm_hw_params struct copy in compat mode
ALSA: seq: Fix snd_seq_call_port_info_ioctl in compat mode
ALSA: hda - Add fixup for Dell Latitidue E6540
ALSA: timer: Fix double unlink of active_list
ALSA: timer: Fix race among timer ioctls
ALSA: hda - fix the headset mic detection problem for a Dell laptop
ALSA: timer: Harden slave timer list handling
ALSA: usb-audio: Fix mixer ctl regression of Native Instrument devices
ALSA: hda - Fix white noise on Dell Latitude E5550
ALSA: seq: Fix race at timer setup and close
ALSA: usb-audio: Avoid calling usb_autopm_put_interface() at disconnect
ALSA: seq: Fix missing NULL check at remove_events ioctl
ALSA: hda - Fixup inverted internal mic for Lenovo E50-80
ALSA: usb: Add native DSD support for Oppo HA-1
x86/mm: Improve switch_mm() barrier comments
x86/mm: Add barriers and document switch_mm()-vs-flush synchronization
x86/boot: Double BOOT_HEAP_SIZE to 64KB
x86/reboot/quirks: Add iMac10,1 to pci_reboot_dmi_table[]
kvm: x86: Fix vmwrite to SECONDARY_VM_EXEC_CONTROL
KVM: x86: correctly print #AC in traces
KVM: x86: expose MSR_TSC_AUX to userspace
x86/xen: don't reset vcpu_info on a cancelled suspend
KEYS: Fix keyring ref leak in join_session_keyring()
Conflicts:
arch/arm64/kernel/perf_event.c
drivers/scsi/sd.c
sound/core/compress_offload.c
Change-Id: I9f77fe42aaae249c24cd6e170202110ab1426878
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>
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commit caaee6234d05a58c5b4d05e7bf766131b810a657 upstream.
By checking the effective credentials instead of the real UID / permitted
capabilities, ensure that the calling process actually intended to use its
credentials.
To ensure that all ptrace checks use the correct caller credentials (e.g.
in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS
flag), use two new flags and require one of them to be set.
The problem was that when a privileged task had temporarily dropped its
privileges, e.g. by calling setreuid(0, user_uid), with the intent to
perform following syscalls with the credentials of a user, it still passed
ptrace access checks that the user would not be able to pass.
While an attacker should not be able to convince the privileged task to
perform a ptrace() syscall, this is a problem because the ptrace access
check is reused for things in procfs.
In particular, the following somewhat interesting procfs entries only rely
on ptrace access checks:
/proc/$pid/stat - uses the check for determining whether pointers
should be visible, useful for bypassing ASLR
/proc/$pid/maps - also useful for bypassing ASLR
/proc/$pid/cwd - useful for gaining access to restricted
directories that contain files with lax permissions, e.g. in
this scenario:
lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar
drwx------ root root /root
drwxr-xr-x root root /root/foobar
-rw-r--r-- root root /root/foobar/secret
Therefore, on a system where a root-owned mode 6755 binary changes its
effective credentials as described and then dumps a user-specified file,
this could be used by an attacker to reveal the memory layout of root's
processes or reveal the contents of files he is not allowed to access
(through /proc/$pid/cwd).
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Commit b641072 ("security: Add AID_NET_RAW and AID_NET_ADMIN capability
check in cap_capable().") introduces additional checks for AID_NET_xxx
macros. Since the header file including those macros are conditionally
included, the checks should also be conditionally executed.
Change-Id: Iaec5208d5b95a46b1ac3f2db8449c661e803fa5b
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Andrey Konovalov <andrey.konovalov@linaro.org>
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Signed-off-by: Chia-chi Yeh <chiachi@android.com>
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Per Andrew Morgan's request, add a securebit to allow admins to disable
PR_CAP_AMBIENT_RAISE. This securebit will prevent processes from adding
capabilities to their ambient set.
For simplicity, this disables PR_CAP_AMBIENT_RAISE entirely rather than
just disabling setting previously cleared bits.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Andrew G. Morgan <morgan@kernel.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Aaron Jones <aaronmdjones@gmail.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Andrew G. Morgan <morgan@kernel.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Austin S Hemmelgarn <ahferroin7@gmail.com>
Cc: Markku Savela <msa@moth.iki.fi>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: James Morris <james.l.morris@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Credit where credit is due: this idea comes from Christoph Lameter with
a lot of valuable input from Serge Hallyn. This patch is heavily based
on Christoph's patch.
===== The status quo =====
On Linux, there are a number of capabilities defined by the kernel. To
perform various privileged tasks, processes can wield capabilities that
they hold.
Each task has four capability masks: effective (pE), permitted (pP),
inheritable (pI), and a bounding set (X). When the kernel checks for a
capability, it checks pE. The other capability masks serve to modify
what capabilities can be in pE.
Any task can remove capabilities from pE, pP, or pI at any time. If a
task has a capability in pP, it can add that capability to pE and/or pI.
If a task has CAP_SETPCAP, then it can add any capability to pI, and it
can remove capabilities from X.
Tasks are not the only things that can have capabilities; files can also
have capabilities. A file can have no capabilty information at all [1].
If a file has capability information, then it has a permitted mask (fP)
and an inheritable mask (fI) as well as a single effective bit (fE) [2].
File capabilities modify the capabilities of tasks that execve(2) them.
A task that successfully calls execve has its capabilities modified for
the file ultimately being excecuted (i.e. the binary itself if that
binary is ELF or for the interpreter if the binary is a script.) [3] In
the capability evolution rules, for each mask Z, pZ represents the old
value and pZ' represents the new value. The rules are:
pP' = (X & fP) | (pI & fI)
pI' = pI
pE' = (fE ? pP' : 0)
X is unchanged
For setuid binaries, fP, fI, and fE are modified by a moderately
complicated set of rules that emulate POSIX behavior. Similarly, if
euid == 0 or ruid == 0, then fP, fI, and fE are modified differently
(primary, fP and fI usually end up being the full set). For nonroot
users executing binaries with neither setuid nor file caps, fI and fP
are empty and fE is false.
As an extra complication, if you execute a process as nonroot and fE is
set, then the "secure exec" rules are in effect: AT_SECURE gets set,
LD_PRELOAD doesn't work, etc.
This is rather messy. We've learned that making any changes is
dangerous, though: if a new kernel version allows an unprivileged
program to change its security state in a way that persists cross
execution of a setuid program or a program with file caps, this
persistent state is surprisingly likely to allow setuid or file-capped
programs to be exploited for privilege escalation.
===== The problem =====
Capability inheritance is basically useless.
If you aren't root and you execute an ordinary binary, fI is zero, so
your capabilities have no effect whatsoever on pP'. This means that you
can't usefully execute a helper process or a shell command with elevated
capabilities if you aren't root.
On current kernels, you can sort of work around this by setting fI to
the full set for most or all non-setuid executable files. This causes
pP' = pI for nonroot, and inheritance works. No one does this because
it's a PITA and it isn't even supported on most filesystems.
If you try this, you'll discover that every nonroot program ends up with
secure exec rules, breaking many things.
This is a problem that has bitten many people who have tried to use
capabilities for anything useful.
===== The proposed change =====
This patch adds a fifth capability mask called the ambient mask (pA).
pA does what most people expect pI to do.
pA obeys the invariant that no bit can ever be set in pA if it is not
set in both pP and pI. Dropping a bit from pP or pI drops that bit from
pA. This ensures that existing programs that try to drop capabilities
still do so, with a complication. Because capability inheritance is so
broken, setting KEEPCAPS, using setresuid to switch to nonroot uids, and
then calling execve effectively drops capabilities. Therefore,
setresuid from root to nonroot conditionally clears pA unless
SECBIT_NO_SETUID_FIXUP is set. Processes that don't like this can
re-add bits to pA afterwards.
The capability evolution rules are changed:
pA' = (file caps or setuid or setgid ? 0 : pA)
pP' = (X & fP) | (pI & fI) | pA'
pI' = pI
pE' = (fE ? pP' : pA')
X is unchanged
If you are nonroot but you have a capability, you can add it to pA. If
you do so, your children get that capability in pA, pP, and pE. For
example, you can set pA = CAP_NET_BIND_SERVICE, and your children can
automatically bind low-numbered ports. Hallelujah!
Unprivileged users can create user namespaces, map themselves to a
nonzero uid, and create both privileged (relative to their namespace)
and unprivileged process trees. This is currently more or less
impossible. Hallelujah!
You cannot use pA to try to subvert a setuid, setgid, or file-capped
program: if you execute any such program, pA gets cleared and the
resulting evolution rules are unchanged by this patch.
Users with nonzero pA are unlikely to unintentionally leak that
capability. If they run programs that try to drop privileges, dropping
privileges will still work.
It's worth noting that the degree of paranoia in this patch could
possibly be reduced without causing serious problems. Specifically, if
we allowed pA to persist across executing non-pA-aware setuid binaries
and across setresuid, then, naively, the only capabilities that could
leak as a result would be the capabilities in pA, and any attacker
*already* has those capabilities. This would make me nervous, though --
setuid binaries that tried to privilege-separate might fail to do so,
and putting CAP_DAC_READ_SEARCH or CAP_DAC_OVERRIDE into pA could have
unexpected side effects. (Whether these unexpected side effects would
be exploitable is an open question.) I've therefore taken the more
paranoid route. We can revisit this later.
An alternative would be to require PR_SET_NO_NEW_PRIVS before setting
ambient capabilities. I think that this would be annoying and would
make granting otherwise unprivileged users minor ambient capabilities
(CAP_NET_BIND_SERVICE or CAP_NET_RAW for example) much less useful than
it is with this patch.
===== Footnotes =====
[1] Files that are missing the "security.capability" xattr or that have
unrecognized values for that xattr end up with has_cap set to false.
The code that does that appears to be complicated for no good reason.
[2] The libcap capability mask parsers and formatters are dangerously
misleading and the documentation is flat-out wrong. fE is *not* a mask;
it's a single bit. This has probably confused every single person who
has tried to use file capabilities.
[3] Linux very confusingly processes both the script and the interpreter
if applicable, for reasons that elude me. The results from thinking
about a script's file capabilities and/or setuid bits are mostly
discarded.
Preliminary userspace code is here, but it needs updating:
https://git.kernel.org/cgit/linux/kernel/git/luto/util-linux-playground.git/commit/?h=cap_ambient&id=7f5afbd175d2
Here is a test program that can be used to verify the functionality
(from Christoph):
/*
* Test program for the ambient capabilities. This program spawns a shell
* that allows running processes with a defined set of capabilities.
*
* (C) 2015 Christoph Lameter <cl@linux.com>
* Released under: GPL v3 or later.
*
*
* Compile using:
*
* gcc -o ambient_test ambient_test.o -lcap-ng
*
* This program must have the following capabilities to run properly:
* Permissions for CAP_NET_RAW, CAP_NET_ADMIN, CAP_SYS_NICE
*
* A command to equip the binary with the right caps is:
*
* setcap cap_net_raw,cap_net_admin,cap_sys_nice+p ambient_test
*
*
* To get a shell with additional caps that can be inherited by other processes:
*
* ./ambient_test /bin/bash
*
*
* Verifying that it works:
*
* From the bash spawed by ambient_test run
*
* cat /proc/$$/status
*
* and have a look at the capabilities.
*/
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <cap-ng.h>
#include <sys/prctl.h>
#include <linux/capability.h>
/*
* Definitions from the kernel header files. These are going to be removed
* when the /usr/include files have these defined.
*/
#define PR_CAP_AMBIENT 47
#define PR_CAP_AMBIENT_IS_SET 1
#define PR_CAP_AMBIENT_RAISE 2
#define PR_CAP_AMBIENT_LOWER 3
#define PR_CAP_AMBIENT_CLEAR_ALL 4
static void set_ambient_cap(int cap)
{
int rc;
capng_get_caps_process();
rc = capng_update(CAPNG_ADD, CAPNG_INHERITABLE, cap);
if (rc) {
printf("Cannot add inheritable cap\n");
exit(2);
}
capng_apply(CAPNG_SELECT_CAPS);
/* Note the two 0s at the end. Kernel checks for these */
if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, cap, 0, 0)) {
perror("Cannot set cap");
exit(1);
}
}
int main(int argc, char **argv)
{
int rc;
set_ambient_cap(CAP_NET_RAW);
set_ambient_cap(CAP_NET_ADMIN);
set_ambient_cap(CAP_SYS_NICE);
printf("Ambient_test forking shell\n");
if (execv(argv[1], argv + 1))
perror("Cannot exec");
return 0;
}
Signed-off-by: Christoph Lameter <cl@linux.com> # Original author
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Aaron Jones <aaronmdjones@gmail.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Andrew G. Morgan <morgan@kernel.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Austin S Hemmelgarn <ahferroin7@gmail.com>
Cc: Markku Savela <msa@moth.iki.fi>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: James Morris <james.l.morris@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Instead of using a vector of security operations
with explicit, special case stacking of the capability
and yama hooks use lists of hooks with capability and
yama hooks included as appropriate.
The security_operations structure is no longer required.
Instead, there is a union of the function pointers that
allows all the hooks lists to use a common mechanism for
list management while retaining typing. Each module
supplies an array describing the hooks it provides instead
of a sparsely populated security_operations structure.
The description includes the element that gets put on
the hook list, avoiding the issues surrounding individual
element allocation.
The method for registering security modules is changed to
reflect the information available. The method for removing
a module, currently only used by SELinux, has also changed.
It should be generic now, however if there are potential
race conditions based on ordering of hook removal that needs
to be addressed by the calling module.
The security hooks are called from the lists and the first
failure is returned.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <james.l.morris@oracle.com>
|
|
most of the ->d_inode uses there refer to the same inode IO would
go to, i.e. d_backing_inode()
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
This is effectively a revert of 7b9a7ec565505699f503b4fcf61500dceb36e744
plus fixing it a different way...
We found, when trying to run an application from an application which
had dropped privs that the kernel does security checks on undefined
capability bits. This was ESPECIALLY difficult to debug as those
undefined bits are hidden from /proc/$PID/status.
Consider a root application which drops all capabilities from ALL 4
capability sets. We assume, since the application is going to set
eff/perm/inh from an array that it will clear not only the defined caps
less than CAP_LAST_CAP, but also the higher 28ish bits which are
undefined future capabilities.
The BSET gets cleared differently. Instead it is cleared one bit at a
time. The problem here is that in security/commoncap.c::cap_task_prctl()
we actually check the validity of a capability being read. So any task
which attempts to 'read all things set in bset' followed by 'unset all
things set in bset' will not even attempt to unset the undefined bits
higher than CAP_LAST_CAP.
So the 'parent' will look something like:
CapInh: 0000000000000000
CapPrm: 0000000000000000
CapEff: 0000000000000000
CapBnd: ffffffc000000000
All of this 'should' be fine. Given that these are undefined bits that
aren't supposed to have anything to do with permissions. But they do...
So lets now consider a task which cleared the eff/perm/inh completely
and cleared all of the valid caps in the bset (but not the invalid caps
it couldn't read out of the kernel). We know that this is exactly what
the libcap-ng library does and what the go capabilities library does.
They both leave you in that above situation if you try to clear all of
you capapabilities from all 4 sets. If that root task calls execve()
the child task will pick up all caps not blocked by the bset. The bset
however does not block bits higher than CAP_LAST_CAP. So now the child
task has bits in eff which are not in the parent. These are
'meaningless' undefined bits, but still bits which the parent doesn't
have.
The problem is now in cred_cap_issubset() (or any operation which does a
subset test) as the child, while a subset for valid cap bits, is not a
subset for invalid cap bits! So now we set durring commit creds that
the child is not dumpable. Given it is 'more priv' than its parent. It
also means the parent cannot ptrace the child and other stupidity.
The solution here:
1) stop hiding capability bits in status
This makes debugging easier!
2) stop giving any task undefined capability bits. it's simple, it you
don't put those invalid bits in CAP_FULL_SET you won't get them in init
and you won't get them in any other task either.
This fixes the cap_issubset() tests and resulting fallout (which
made the init task in a docker container untraceable among other
things)
3) mask out undefined bits when sys_capset() is called as it might use
~0, ~0 to denote 'all capabilities' for backward/forward compatibility.
This lets 'capsh --caps="all=eip" -- -c /bin/bash' run.
4) mask out undefined bit when we read a file capability off of disk as
again likely all bits are set in the xattr for forward/backward
compatibility.
This lets 'setcap all+pe /bin/bash; /bin/bash' run
Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Andrew G. Morgan <morgan@kernel.org>
Cc: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Steve Grubb <sgrubb@redhat.com>
Cc: Dan Walsh <dwalsh@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
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In function cap_task_prctl(), we would allocate a credential
unconditionally and then check if we support the requested function.
If not we would release this credential with abort_creds() by using
RCU method. But on some archs such as powerpc, the sys_prctl is heavily
used to get/set the floating point exception mode. So the unnecessary
allocating/releasing of credential not only introduce runtime overhead
but also do cause OOM due to the RCU implementation.
This patch removes abort_creds() from cap_task_prctl() by calling
prepare_creds() only when we need to modify it.
Reported-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
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We allow task A to change B's nice level if it has a supserset of
B's privileges, or of it has CAP_SYS_NICE. Also allow it if A has
CAP_SYS_NICE with respect to B - meaning it is root in the same
namespace, or it created B's namespace.
Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
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As the capabilites and capability bounding set are per user namespace
properties it is safe to allow changing them with just CAP_SETPCAP
permission in the user namespace.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Tested-by: Richard Weinberger <richard@nod.at>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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very few users left...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
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Andy Lutomirski pointed out that the current behavior of allowing the
owner of a user namespace to have all caps when that owner is not in a
parent user namespace is wrong. Add a test to ensure the owner of a user
namespace is in the parent of the user namespace to fix this bug.
Thankfully this bug did not apply to the initial user namespace, keeping
the mischief that can be caused by this bug quite small.
This is bug was introduced in v3.5 by commit 783291e6900
"Simplify the user_namespace by making userns->creator a kuid."
But did not matter until the permisions required to create
a user namespace were relaxed allowing a user namespace to be created
inside of a user namespace.
The bug made it possible for the owner of a user namespace to be
present in a child user namespace. Since the owner of a user nameapce
is granted all capabilities it became possible for users in a
grandchild user namespace to have all privilges over their parent user
namspace.
Reorder the checks in cap_capable. This should make the common case
faster and make it clear that nothing magic happens in the initial
user namespace. The reordering is safe because cred->user_ns
can only be in targ_ns or targ_ns->parent but not both.
Add a comment a the top of the loop to make the logic of
the code clear.
Add a distinct variable ns that changes as we walk up
the user namespace hierarchy to make it clear which variable
is changing.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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... i.e. file-dependent and address-dependent checks.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
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... switch callers.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace enhancements from Eric Biederman:
"This is a course correction for the user namespace, so that we can
reach an inexpensive, maintainable, and reasonably complete
implementation.
Highlights:
- Config guards make it impossible to enable the user namespace and
code that has not been converted to be user namespace safe.
- Use of the new kuid_t type ensures the if you somehow get past the
config guards the kernel will encounter type errors if you enable
user namespaces and attempt to compile in code whose permission
checks have not been updated to be user namespace safe.
- All uids from child user namespaces are mapped into the initial
user namespace before they are processed. Removing the need to add
an additional check to see if the user namespace of the compared
uids remains the same.
- With the user namespaces compiled out the performance is as good or
better than it is today.
- For most operations absolutely nothing changes performance or
operationally with the user namespace enabled.
- The worst case performance I could come up with was timing 1
billion cache cold stat operations with the user namespace code
enabled. This went from 156s to 164s on my laptop (or 156ns to
164ns per stat operation).
- (uid_t)-1 and (gid_t)-1 are reserved as an internal error value.
Most uid/gid setting system calls treat these value specially
anyway so attempting to use -1 as a uid would likely cause
entertaining failures in userspace.
- If setuid is called with a uid that can not be mapped setuid fails.
I have looked at sendmail, login, ssh and every other program I
could think of that would call setuid and they all check for and
handle the case where setuid fails.
- If stat or a similar system call is called from a context in which
we can not map a uid we lie and return overflowuid. The LFS
experience suggests not lying and returning an error code might be
better, but the historical precedent with uids is different and I
can not think of anything that would break by lying about a uid we
can't map.
- Capabilities are localized to the current user namespace making it
safe to give the initial user in a user namespace all capabilities.
My git tree covers all of the modifications needed to convert the core
kernel and enough changes to make a system bootable to runlevel 1."
Fix up trivial conflicts due to nearby independent changes in fs/stat.c
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits)
userns: Silence silly gcc warning.
cred: use correct cred accessor with regards to rcu read lock
userns: Convert the move_pages, and migrate_pages permission checks to use uid_eq
userns: Convert cgroup permission checks to use uid_eq
userns: Convert tmpfs to use kuid and kgid where appropriate
userns: Convert sysfs to use kgid/kuid where appropriate
userns: Convert sysctl permission checks to use kuid and kgids.
userns: Convert proc to use kuid/kgid where appropriate
userns: Convert ext4 to user kuid/kgid where appropriate
userns: Convert ext3 to use kuid/kgid where appropriate
userns: Convert ext2 to use kuid/kgid where appropriate.
userns: Convert devpts to use kuid/kgid where appropriate
userns: Convert binary formats to use kuid/kgid where appropriate
userns: Add negative depends on entries to avoid building code that is userns unsafe
userns: signal remove unnecessary map_cred_ns
userns: Teach inode_capable to understand inodes whose uids map to other namespaces.
userns: Fail exec for suid and sgid binaries with ids outside our user namespace.
userns: Convert stat to return values mapped from kuids and kgids
userns: Convert user specfied uids and gids in chown into kuids and kgid
userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs
...
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Linux 3.4-rc5
Merge to pull in prerequisite change for Smack:
86812bb0de1a3758dc6c7aa01a763158a7c0638a
Requested by Casey.
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- Use uid_eq when comparing kuids
Use gid_eq when comparing kgids
- Use make_kuid(user_ns, 0) to talk about the user_namespace root uid
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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cred.h and a few trivial users of struct cred are changed. The rest of the users
of struct cred are left for other patches as there are too many changes to make
in one go and leave the change reviewable. If the user namespace is disabled and
CONFIG_UIDGID_STRICT_TYPE_CHECKS are disabled the code will contiue to compile
and behave correctly.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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- Transform userns->creator from a user_struct reference to a simple
kuid_t, kgid_t pair.
In cap_capable this allows the check to see if we are the creator of
a namespace to become the classic suser style euid permission check.
This allows us to remove the need for a struct cred in the mapping
functions and still be able to dispaly the user namespace creators
uid and gid as 0.
- Remove the now unnecessary delayed_work in free_user_ns.
All that is left for free_user_ns to do is to call kmem_cache_free
and put_user_ns. Those functions can be called in any context
so call them directly from free_user_ns removing the need for delayed work.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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Add missing "personality.h"
security/commoncap.c: In function 'cap_bprm_set_creds':
security/commoncap.c:510: error: 'PER_CLEAR_ON_SETID' undeclared (first use in this function)
security/commoncap.c:510: error: (Each undeclared identifier is reported only once
security/commoncap.c:510: error: for each function it appears in.)
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
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If a process increases permissions using fcaps all of the dangerous
personality flags which are cleared for suid apps should also be cleared.
Thus programs given priviledge with fcaps will continue to have address space
randomization enabled even if the parent tried to disable it to make it
easier to attack.
Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
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With this change, calling
prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)
disables privilege granting operations at execve-time. For example, a
process will not be able to execute a setuid binary to change their uid
or gid if this bit is set. The same is true for file capabilities.
Additionally, LSM_UNSAFE_NO_NEW_PRIVS is defined to ensure that
LSMs respect the requested behavior.
To determine if the NO_NEW_PRIVS bit is set, a task may call
prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
It returns 1 if set and 0 if it is not set. If any of the arguments are
non-zero, it will return -1 and set errno to -EINVAL.
(PR_SET_NO_NEW_PRIVS behaves similarly.)
This functionality is desired for the proposed seccomp filter patch
series. By using PR_SET_NO_NEW_PRIVS, it allows a task to modify the
system call behavior for itself and its child tasks without being
able to impact the behavior of a more privileged task.
Another potential use is making certain privileged operations
unprivileged. For example, chroot may be considered "safe" if it cannot
affect privileged tasks.
Note, this patch causes execve to fail when PR_SET_NO_NEW_PRIVS is
set and AppArmor is in use. It is fixed in a subsequent patch.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Will Drewry <wad@chromium.org>
Acked-by: Eric Paris <eparis@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
v18: updated change desc
v17: using new define values as per 3.4
Signed-off-by: James Morris <james.l.morris@oracle.com>
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I am about to remove the struct user_namespace reference from struct user_struct.
So keep an explicit track of the parent user namespace.
Take advantage of this new reference and replace instances of user_ns->creator->user_ns
with user_ns->parent.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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Optimize performance and prepare for the removal of the user_ns reference
from user_struct. Remove the slow long walk through cred->user->user_ns and
instead go straight to cred->user_ns.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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Trim security.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Morris <jmorris@namei.org>
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* 'for-linus' of git://selinuxproject.org/~jmorris/linux-security:
capabilities: remove __cap_full_set definition
security: remove the security_netlink_recv hook as it is equivalent to capable()
ptrace: do not audit capability check when outputing /proc/pid/stat
capabilities: remove task_ns_* functions
capabitlies: ns_capable can use the cap helpers rather than lsm call
capabilities: style only - move capable below ns_capable
capabilites: introduce new has_ns_capabilities_noaudit
capabilities: call has_ns_capability from has_capability
capabilities: remove all _real_ interfaces
capabilities: introduce security_capable_noaudit
capabilities: reverse arguments to security_capable
capabilities: remove the task from capable LSM hook entirely
selinux: sparse fix: fix several warnings in the security server cod
selinux: sparse fix: fix warnings in netlink code
selinux: sparse fix: eliminate warnings for selinuxfs
selinux: sparse fix: declare selinux_disable() in security.h
selinux: sparse fix: move selinux_complete_init
selinux: sparse fix: make selinux_secmark_refcount static
SELinux: Fix RCU deref check warning in sel_netport_insert()
Manually fix up a semantic mis-merge wrt security_netlink_recv():
- the interface was removed in commit fd7784615248 ("security: remove
the security_netlink_recv hook as it is equivalent to capable()")
- a new user of it appeared in commit a38f7907b926 ("crypto: Add
userspace configuration API")
causing no automatic merge conflict, but Eric Paris pointed out the
issue.
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Once upon a time netlink was not sync and we had to get the effective
capabilities from the skb that was being received. Today we instead get
the capabilities from the current task. This has rendered the entire
purpose of the hook moot as it is now functionally equivalent to the
capable() call.
Signed-off-by: Eric Paris <eparis@redhat.com>
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The capabilities framework is based around credentials, not necessarily the
current task. Yet we still passed the current task down into LSMs from the
security_capable() LSM hook as if it was a meaningful portion of the security
decision. This patch removes the 'generic' passing of current and instead
forces individual LSMs to use current explicitly if they think it is
appropriate. In our case those LSMs are SELinux and AppArmor.
I believe the AppArmor use of current is incorrect, but that is wholely
unrelated to this patch. This patch does not change what AppArmor does, it
just makes it clear in the AppArmor code that it is doing it.
The SELinux code still uses current in it's audit message, which may also be
wrong and needs further investigation. Again this is NOT a change, it may
have always been wrong, this patch just makes it clear what is happening.
Signed-off-by: Eric Paris <eparis@redhat.com>
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Initialize has_cap in cap_bprm_set_creds()
Reported-by: Andrew G. Morgan <morgan@kernel.org>
Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
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caps
A task (when !SECURE_NOROOT) which executes a setuid-root binary will
obtain root privileges while executing that binary. If the binary also
has effective capabilities set, then only those capabilities will be
granted. The rationale is that the same binary can carry both setuid-root
and the minimal file capability set, so that on a filesystem not
supporting file caps the binary can still be executed with privilege,
while on a filesystem supporting file caps it will run with minimal
privilege.
This special case currently does NOT happen if there are file capabilities
but no effective capabilities. Since capability-aware programs can very
well start with empty pE but populated pP and move those caps to pE when
needed. In other words, if the file has file capabilities but NOT
effective capabilities, then we should do the same thing as if there
were file capabilities, and not grant full root privileges.
This patchset does that.
(Changelog by Serge Hallyn).
Signed-off-by: Zhi Li <lizhi1215@gmail.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
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When the global init task is exec'd we have special case logic to make sure
the pE is not reduced. There is no reason for this. If init wants to drop
it's pE is should be allowed to do so. Remove this special logic.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Andrew G. Morgan <morgan@kernel.org>
Signed-off-by: James Morris <jmorris@namei.org>
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ptrace is allowed to tasks in the same user namespace according to the
usual rules (i.e. the same rules as for two tasks in the init user
namespace). ptrace is also allowed to a user namespace to which the
current task the has CAP_SYS_PTRACE capability.
Changelog:
Dec 31: Address feedback by Eric:
. Correct ptrace uid check
. Rename may_ptrace_ns to ptrace_capable
. Also fix the cap_ptrace checks.
Jan 1: Use const cred struct
Jan 11: use task_ns_capable() in place of ptrace_capable().
Feb 23: same_or_ancestore_user_ns() was not an appropriate
check to constrain cap_issubset. Rather, cap_issubset()
only is meaningful when both capsets are in the same
user_ns.
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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- Introduce ns_capable to test for a capability in a non-default
user namespace.
- Teach cap_capable to handle capabilities in a non-default
user namespace.
The motivation is to get to the unprivileged creation of new
namespaces. It looks like this gets us 90% of the way there, with
only potential uid confusion issues left.
I still need to handle getting all caps after creation but otherwise I
think I have a good starter patch that achieves all of your goals.
Changelog:
11/05/2010: [serge] add apparmor
12/14/2010: [serge] fix capabilities to created user namespaces
Without this, if user serge creates a user_ns, he won't have
capabilities to the user_ns he created. THis is because we
were first checking whether his effective caps had the caps
he needed and returning -EPERM if not, and THEN checking whether
he was the creator. Reverse those checks.
12/16/2010: [serge] security_real_capable needs ns argument in !security case
01/11/2011: [serge] add task_ns_capable helper
01/11/2011: [serge] add nsown_capable() helper per Bastian Blank suggestion
02/16/2011: [serge] fix a logic bug: the root user is always creator of
init_user_ns, but should not always have capabilities to
it! Fix the check in cap_capable().
02/21/2011: Add the required user_ns parameter to security_capable,
fixing a compile failure.
02/23/2011: Convert some macros to functions as per akpm comments. Some
couldn't be converted because we can't easily forward-declare
them (they are inline if !SECURITY, extern if SECURITY). Add
a current_user_ns function so we can use it in capability.h
without #including cred.h. Move all forward declarations
together to the top of the #ifdef __KERNEL__ section, and use
kernel-doc format.
02/23/2011: Per dhowells, clean up comment in cap_capable().
02/23/2011: Per akpm, remove unreachable 'return -EPERM' in cap_capable.
(Original written and signed off by Eric; latest, modified version
acked by him)
[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: export current_user_ns() for ecryptfs]
[serge.hallyn@canonical.com: remove unneeded extra argument in selinux's task_has_capability]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1480 commits)
bonding: enable netpoll without checking link status
xfrm: Refcount destination entry on xfrm_lookup
net: introduce rx_handler results and logic around that
bonding: get rid of IFF_SLAVE_INACTIVE netdev->priv_flag
bonding: wrap slave state work
net: get rid of multiple bond-related netdevice->priv_flags
bonding: register slave pointer for rx_handler
be2net: Bump up the version number
be2net: Copyright notice change. Update to Emulex instead of ServerEngines
e1000e: fix kconfig for crc32 dependency
netfilter ebtables: fix xt_AUDIT to work with ebtables
xen network backend driver
bonding: Improve syslog message at device creation time
bonding: Call netif_carrier_off after register_netdevice
bonding: Incorrect TX queue offset
net_sched: fix ip_tos2prio
xfrm: fix __xfrm_route_forward()
be2net: Fix UDP packet detected status in RX compl
Phonet: fix aligned-mode pipe socket buffer header reserve
netxen: support for GbE port settings
...
Fix up conflicts in drivers/staging/brcm80211/brcmsmac/wl_mac80211.c
with the staging updates.
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Netlink message processing in the kernel is synchronous these days,
capabilities can be checked directly in security_netlink_recv() from
the current process.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Reviewed-by: James Morris <jmorris@namei.org>
[chrisw: update to include pohmelfs and uvesafb]
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Both settimeofday() and clock_settime() promise with a 'const'
attribute not to alter the arguments passed in. This patch adds the
missing 'const' attribute into the various kernel functions
implementing these calls.
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <20110201134417.545698637@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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The addition of CONFIG_SECURITY_DMESG_RESTRICT resulted in a build
failure when CONFIG_PRINTK=n. This is because the capabilities code
which used the new option was built even though the variable in question
didn't exist.
The patch here fixes this by moving the capabilities checks out of the
LSM and into the caller. All (known) LSMs should have been calling the
capabilities hook already so it actually makes the code organization
better to eliminate the hook altogether.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The kernel syslog contains debugging information that is often useful
during exploitation of other vulnerabilities, such as kernel heap
addresses. Rather than futilely attempt to sanitize hundreds (or
thousands) of printk statements and simultaneously cripple useful
debugging functionality, it is far simpler to create an option that
prevents unprivileged users from reading the syslog.
This patch, loosely based on grsecurity's GRKERNSEC_DMESG, creates the
dmesg_restrict sysctl. When set to "0", the default, no restrictions are
enforced. When set to "1", only users with CAP_SYS_ADMIN can read the
kernel syslog via dmesg(8) or other mechanisms.
[akpm@linux-foundation.org: explain the config option in kernel.txt]
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Eugene Teo <eugeneteo@kernel.org>
Acked-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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All security modules shouldn't change sched_param parameter of
security_task_setscheduler(). This is not only meaningless, but also
make a harmful result if caller pass a static variable.
This patch remove policy and sched_param parameter from
security_task_setscheduler() becuase none of security module is
using it.
Cc: James Morris <jmorris@namei.org>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: James Morris <jmorris@namei.org>
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Make do_execve() take a const filename pointer so that kernel_execve() compiles
correctly on ARM:
arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type
This also requires the argv and envp arguments to be consted twice, once for
the pointer array and once for the strings the array points to. This is
because do_execve() passes a pointer to the filename (now const) to
copy_strings_kernel(). A simpler alternative would be to cast the filename
pointer in do_execve() when it's passed to copy_strings_kernel().
do_execve() may not change any of the strings it is passed as part of the argv
or envp lists as they are some of them in .rodata, so marking these strings as
const should be fine.
Further kernel_execve() and sys_execve() need to be changed to match.
This has been test built on x86_64, frv, arm and mips.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Whitespace coding style fixes.
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: James Morris <jmorris@namei.org>
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In the comment of cap_file_mmap(), replace mmap_min_addr to be dac_mmap_min_addr.
Signed-off-by: Zhitong Wang <zhitong.wangzt@alibaba-inc.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
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Drop my typoed comment as it is both unhelpful and redundant.
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
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Right now the syslog "type" action are just raw numbers which makes
the source difficult to follow. This patch replaces the raw numbers
with defined constants for some level of sanity.
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
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This allows the LSM to distinguish between syslog functions originating
from /proc/kmsg access and direct syscalls. By default, the commoncaps
will now no longer require CAP_SYS_ADMIN to read an opened /proc/kmsg
file descriptor. For example the kernel syslog reader can now drop
privileges after opening /proc/kmsg, instead of staying privileged with
CAP_SYS_ADMIN. MAC systems that implement security_syslog have unchanged
behavior.
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
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As far as I know, all distros currently ship kernels with default
CONFIG_SECURITY_FILE_CAPABILITIES=y. Since having the option on
leaves a 'no_file_caps' option to boot without file capabilities,
the main reason to keep the option is that turning it off saves
you (on my s390x partition) 5k. In particular, vmlinux sizes
came to:
without patch fscaps=n: 53598392
without patch fscaps=y: 53603406
with this patch applied: 53603342
with the security-next tree.
Against this we must weigh the fact that there is no simple way for
userspace to figure out whether file capabilities are supported,
while things like per-process securebits, capability bounding
sets, and adding bits to pI if CAP_SETPCAP is in pE are not supported
with SECURITY_FILE_CAPABILITIES=n, leaving a bit of a problem for
applications wanting to know whether they can use them and/or why
something failed.
It also adds another subtly different set of semantics which we must
maintain at the risk of severe security regressions.
So this patch removes the SECURITY_FILE_CAPABILITIES compile
option. It drops the kernel size by about 50k over the stock
SECURITY_FILE_CAPABILITIES=y kernel, by removing the
cap_limit_ptraced_target() function.
Changelog:
Nov 20: remove cap_limit_ptraced_target() as it's logic
was ifndef'ed.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: Andrew G. Morgan" <morgan@kernel.org>
Signed-off-by: James Morris <jmorris@namei.org>
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