[PATCH 2/2] Smack: prevent underflow in smk_set_cipso()
From: Dan Carpenter <hidden>
Date: 2020-07-23 15:25:56
Also in:
lkml
Subsystem:
security subsystem, smack security module, the rest · Maintainers:
Paul Moore, James Morris, "Serge E. Hallyn", Casey Schaufler, Linus Torvalds
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 <redacted>
---
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 81c6ceeaa4f9..7675305511ef 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c@@ -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;
--
2.27.0