| From cfe9bc8fdb49ba797a3f963f56712bbe5c800188 Mon Sep 17 00:00:00 2001 |
| From: Dan Carpenter <dan.carpenter@oracle.com> |
| Date: Thu, 23 Jul 2020 18:23:05 +0300 |
| Subject: [PATCH] Smack: prevent underflow in smk_set_cipso() |
| |
| commit 42a2df3e829f3c5562090391b33714b2e2e5ad4a upstream. |
| |
| We have an upper bound on "maplevel" but forgot to check for negative |
| values. |
| |
| Fixes: e114e473771c ("Smack: Simplified Mandatory Access Control Kernel") |
| Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> |
| Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c |
| index fd6207473fd4..8c000344b7ec 100644 |
| --- a/security/smack/smackfs.c |
| +++ b/security/smack/smackfs.c |
| @@ -883,7 +883,7 @@ 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; |
| -- |
| 2.27.0 |
| |
