smackfs: Prevent underflow in smk_set_cipso()

[ Upstream commit 3ad49d37cf ]

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: e114e47377 ("Smack: Simplified Mandatory Access Control Kernel")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Dan Carpenter 2023-07-06 08:52:39 +03:00 committed by Greg Kroah-Hartman
parent d1994bb594
commit d41ceafe3d
1 changed files with 1 additions and 1 deletions

View File

@ -896,7 +896,7 @@ 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 &&