crypto: msm: Fix buffer overflow issue

In multi-threaded environment diglen variable could be modified
by multiple threads at the same time. Buffer overflow might
happen in current thread if another thread changes the diglen
variable. So add mutex locks to avoid this issue.

Change-Id: I62c63c55c028dedb1dd0eec862851bd8e818a5d3
Signed-off-by: AnilKumar Chimata <anilc@codeaurora.org>

1 files changed, 41 insertions, 10 deletions

diff --git a/drivers/crypto/msm/qcedev.c b/drivers/crypto/msm/qcedev.c
index 7459401979fe..d04ca6f28f90 100644
--- a/drivers/crypto/msm/qcedev.c
+++ b/drivers/crypto/msm/qcedev.c
@@ -56,6 +56,7 @@ static uint8_t _std_init_vector_sha256_uint8[] = {
 
 static DEFINE_MUTEX(send_cmd_lock);
 static DEFINE_MUTEX(qcedev_sent_bw_req);
+static DEFINE_MUTEX(hash_access_lock);
 
 static void qcedev_ce_high_bw_req(struct qcedev_control *podev,
 							bool high_bw_req)
@@ -1648,12 +1649,18 @@ long qcedev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 					(void __user *)arg,
 					sizeof(struct qcedev_sha_op_req)))
 			return -EFAULT;
-		if (qcedev_check_sha_params(&qcedev_areq.sha_op_req, podev))
+		mutex_lock(&hash_access_lock);
+		if (qcedev_check_sha_params(&qcedev_areq.sha_op_req, podev)) {
+			mutex_unlock(&hash_access_lock);
 			return -EINVAL;
+		}
 		qcedev_areq.op_type = QCEDEV_CRYPTO_OPER_SHA;
 		err = qcedev_hash_init(&qcedev_areq, handle, &sg_src);
-		if (err)
+		if (err) {
+			mutex_unlock(&hash_access_lock);
 			return err;
+		}
+		mutex_unlock(&hash_access_lock);
 		if (copy_to_user((void __user *)arg, &qcedev_areq.sha_op_req,
 					sizeof(struct qcedev_sha_op_req)))
 			return -EFAULT;
@@ -1671,32 +1678,42 @@ long qcedev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 					(void __user *)arg,
 					sizeof(struct qcedev_sha_op_req)))
 			return -EFAULT;
-		if (qcedev_check_sha_params(&qcedev_areq.sha_op_req, podev))
+		mutex_lock(&hash_access_lock);
+		if (qcedev_check_sha_params(&qcedev_areq.sha_op_req, podev)) {
+			mutex_unlock(&hash_access_lock);
 			return -EINVAL;
+		}
 		qcedev_areq.op_type = QCEDEV_CRYPTO_OPER_SHA;
 
 		if (qcedev_areq.sha_op_req.alg == QCEDEV_ALG_AES_CMAC) {
 			err = qcedev_hash_cmac(&qcedev_areq, handle, &sg_src);
-			if (err)
+			if (err) {
+				mutex_unlock(&hash_access_lock);
 				return err;
+			}
 		} else {
 			if (handle->sha_ctxt.init_done == false) {
 				pr_err("%s Init was not called\n", __func__);
+				mutex_unlock(&hash_access_lock);
 				return -EINVAL;
 			}
 			err = qcedev_hash_update(&qcedev_areq, handle, &sg_src);
-			if (err)
+			if (err) {
+				mutex_unlock(&hash_access_lock);
 				return err;
+			}
 		}
 
 		if (handle->sha_ctxt.diglen > QCEDEV_MAX_SHA_DIGEST) {
 			pr_err("Invalid sha_ctxt.diglen %d\n",
 					handle->sha_ctxt.diglen);
+			mutex_unlock(&hash_access_lock);
 			return -EINVAL;
 		}
 		memcpy(&qcedev_areq.sha_op_req.digest[0],
 				&handle->sha_ctxt.digest[0],
 				handle->sha_ctxt.diglen);
+		mutex_unlock(&hash_access_lock);
 		if (copy_to_user((void __user *)arg, &qcedev_areq.sha_op_req,
 					sizeof(struct qcedev_sha_op_req)))
 			return -EFAULT;
@@ -1713,16 +1730,22 @@ long qcedev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 					(void __user *)arg,
 					sizeof(struct qcedev_sha_op_req)))
 			return -EFAULT;
-		if (qcedev_check_sha_params(&qcedev_areq.sha_op_req, podev))
+		mutex_lock(&hash_access_lock);
+		if (qcedev_check_sha_params(&qcedev_areq.sha_op_req, podev)) {
+			mutex_unlock(&hash_access_lock);
 			return -EINVAL;
+		}
 		qcedev_areq.op_type = QCEDEV_CRYPTO_OPER_SHA;
 		err = qcedev_hash_final(&qcedev_areq, handle);
-		if (err)
+		if (err) {
+			mutex_unlock(&hash_access_lock);
 			return err;
+		}
 		qcedev_areq.sha_op_req.diglen = handle->sha_ctxt.diglen;
 		memcpy(&qcedev_areq.sha_op_req.digest[0],
 				&handle->sha_ctxt.digest[0],
 				handle->sha_ctxt.diglen);
+		mutex_unlock(&hash_access_lock);
 		if (copy_to_user((void __user *)arg, &qcedev_areq.sha_op_req,
 					sizeof(struct qcedev_sha_op_req)))
 			return -EFAULT;
@@ -1737,20 +1760,28 @@ long qcedev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 					(void __user *)arg,
 					sizeof(struct qcedev_sha_op_req)))
 			return -EFAULT;
-		if (qcedev_check_sha_params(&qcedev_areq.sha_op_req, podev))
+		mutex_lock(&hash_access_lock);
+		if (qcedev_check_sha_params(&qcedev_areq.sha_op_req, podev)) {
+			mutex_unlock(&hash_access_lock);
 			return -EINVAL;
+		}
 		qcedev_areq.op_type = QCEDEV_CRYPTO_OPER_SHA;
 		qcedev_hash_init(&qcedev_areq, handle, &sg_src);
 		err = qcedev_hash_update(&qcedev_areq, handle, &sg_src);
-		if (err)
+		if (err) {
+			mutex_unlock(&hash_access_lock);
 			return err;
+		}
 		err = qcedev_hash_final(&qcedev_areq, handle);
-		if (err)
+		if (err) {
+			mutex_unlock(&hash_access_lock);
 			return err;
+		}
 		qcedev_areq.sha_op_req.diglen =	handle->sha_ctxt.diglen;
 		memcpy(&qcedev_areq.sha_op_req.digest[0],
 				&handle->sha_ctxt.digest[0],
 				handle->sha_ctxt.diglen);
+		mutex_unlock(&hash_access_lock);
 		if (copy_to_user((void __user *)arg, &qcedev_areq.sha_op_req,
 					sizeof(struct qcedev_sha_op_req)))
 			return -EFAULT;