netfilter: nf_ct_ftp: fix deadlock when nat rewrite is needed
[ Upstream commit
d25088932227680988a6b794221e031a7232f137 ]
We can't use ct->lock, this is already used by the seqadj internals.
When using ftp helper + nat, seqadj will attempt to acquire ct->lock
again.
Revert back to a global lock for now.
Fixes: c783a29c7e59 ("netfilter: nf_ct_ftp: prefer skb_linearize")
Reported-by: Bruno de Paula Larini <bruno.larini@riosoft.com.br>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>