This is a note to let you know that I've just added the patch titled
smackfs: Prevent underflow in smk_set_cipso()
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
smackfs-prevent-underflow-in-smk_set_cipso.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit bb9b7e888491e7fd69a5b16d03e5f0fb0fd67a4d
Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Date: Thu Jul 6 08:52:39 2023 +0300
smackfs: Prevent underflow in smk_set_cipso()
[ 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>
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 &&
