netfilter: nf_tables: GC transaction race with netns dismantle

netfilter: nf_tables: GC transaction race with netns dismantle

commit 02c6c24402bf1c1e986899c14ba22a10b510916b upstream.

Use maybe_get_net() since GC workqueue might race with netns exit path.

Fixes: 5f68718b34a5 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Gbp-Pq: Topic bugfix/all
Gbp-Pq: Name netfilter-nf_tables-gc-transaction-race-with-netns-d.patch