This is similar to commit 84e99e58e8d1 ("Smack: slab-out-of-bounds in
vsscanf") where we added a bounds check on "rule".Reported-by: [email protected] Fixes: f7112e6c9abf ("Smack: allow for significantly longer Smack labels v4") Signed-off-by: Dan Carpenter <[email protected]> --- This check is very straight forward and should fix the bug. But if you look at the fixes tag we used to rely on the check: if (count != (SMK_CIPSOMIN + catlen * SMK_DIGITLEN)) and now that has been changed to: if (format == SMK_FIXED24_FMT && count != (SMK_CIPSOMIN + catlen * SMK_DIGITLEN)) goto out; so it doesn't apply for every format. security/smack/smackfs.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index c21b656b3263..81c6ceeaa4f9 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -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; -- 2.27.0
