From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
[ Upstream commit a6bd4f6d9b07452b0b19842044a6c3ea384b0b88 ]
This is similar to commit 84e99e58e8d1 ("Smack: slab-out-of-bounds in
vsscanf") where we added a bounds check on "rule".
Reported-by: syzbot+a22c6092d003d6fe1122@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: f7112e6c9abf ("Smack: allow for significantly longer Smack labels v4")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
security/smack/smackfs.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index bd4d0f5a79aa3..2e2ef3a525ecb 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -939,6 +939,10 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
for (i = 0; i < catlen; i++) {
rule += SMK_DIGITLEN;
+ if (rule > data + count) {
+ rc = -EOVERFLOW;
+ goto out;
+ }
ret = sscanf(rule, "%u", &cat);
if (ret != 1 || cat > SMACK_CIPSO_MAXCATNUM)
goto out;
--
2.25.1
