Commits
Florian Westphal committed 9306425b70b
netfilter: ctnetlink: must check mark attributes vs NULL
else we will oops (null deref) when the attributes aren't present.
Also add back the EOPNOTSUPP in case MARK filtering is requested but
kernel doesn't support it.
Fixes: 59c08c69c2788 ("netfilter: ctnetlink: Support L3 protocol-filter on flush")
Reported-by: syzbot+e45eda8eda6e93a03959@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>