Smack: fix another vsscanf out of bounds

This is similar to commit 84e99e58e8 ("Smack: slab-out-of-bounds in
vsscanf") where we added a bounds check on "rule".

Reported-by: syzbot+a22c6092d003d6fe1122@syzkaller.appspotmail.com
Fixes: f7112e6c9a ("Smack: allow for significantly longer Smack labels v4")
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 18:22:19 +03:00 committed by Casey Schaufler
parent beb4ee6770
commit a6bd4f6d9b
1 changed files with 4 additions and 0 deletions

View File

@ -905,6 +905,10 @@ 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;