netfilter: conntrack: check NULL when retrieving ct extension

nf_ct_ext_find() might return NULL if ct extension is not found.

Add also the null checks to:

- nfct_help()
- nfct_help_data()
- nfct_seqadj()
- nfct_nat()

This is defensive, for safety reasons.

nf_ct_ext_find() used to return NULL if the extension is stale for
unconfirmed conntracks if the genid validation fails.

Skip NULL check in nf_nat_inet_fn() given this is valid to be NULL
for non-initialized ct nat extensions.

While at it, fetch ct helper area in nf_ct_expect_related_report() only
once and pass it on to other ancilliary functions. Replace WARN_ON()
by WARN_ON_ONCE() in nf_ct_unlink_expect_report().

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

0 files changed, 0 insertions, 0 deletions