[PATCH 4.19 102/273] smackfs: Prevent underflow in smk_set_cipso()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

[ Upstream commit 3ad49d37cf5759c3b8b68d02e3563f633d9c1aee ]

There is a upper bound to "catlen" but no lower bound to prevent
negatives.  I don't see that this necessarily causes a problem but we
may as well be safe.

Fixes: e114e473771c ("Smack: Simplified Mandatory Access Control Kernel")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 security/smack/smackfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index a9c516362170a..61e734baa332a 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -923,7 +923,7 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
 	}
 
 	ret = sscanf(rule, "%d", &catlen);
-	if (ret != 1 || catlen > SMACK_CIPSO_MAXCATNUM)
+	if (ret != 1 || catlen < 0 || catlen > SMACK_CIPSO_MAXCATNUM)
 		goto out;
 
 	if (format == SMK_FIXED24_FMT &&
-- 
2.40.1






[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux