Smack: prevent underflow in smk_set_cipso()

We have an upper bound on "maplevel" but forgot to check for negative
values.

Fixes: e114e47377 ("Smack: Simplified Mandatory Access Control Kernel")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
This commit is contained in:
Dan Carpenter 2020-07-23 18:23:05 +03:00 committed by Casey Schaufler
parent a6bd4f6d9b
commit 42a2df3e82
1 changed files with 1 additions and 1 deletions

View File

@ -884,7 +884,7 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
}
ret = sscanf(rule, "%d", &maplevel);
if (ret != 1 || maplevel > SMACK_CIPSO_MAXLEVEL)
if (ret != 1 || maplevel < 0 || maplevel > SMACK_CIPSO_MAXLEVEL)
goto out;
rule += SMK_DIGITLEN;