netfilter: ebtables: CONFIG_COMPAT: reject trailing data after last rule

If userspace provides a rule blob with trailing data after last target,
we trigger a splat, then convert ruleset to 64bit format (with trailing
data), then pass that to do_replace_finish() which then returns -EINVAL.

Erroring out right away avoids the splat plus unneeded translation and
error unwind.

Fixes: 81e675c227 ("netfilter: ebtables: add CONFIG_COMPAT support")
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Florian Westphal 2019-05-05 18:47:33 +02:00 committed by Pablo Neira Ayuso
parent 8cd2bc981c
commit 680f6af533

View File

@ -2158,7 +2158,9 @@ static int compat_copy_entries(unsigned char *data, unsigned int size_user,
if (ret < 0)
return ret;
WARN_ON(size_remaining);
if (size_remaining)
return -EINVAL;
return state->buf_kern_offset;
}