netfilter: nf_nat: fix race when unloading protocol modules
following oops was reported:
RIP: 0010:[<ffffffffa03227f2>] [<ffffffffa03227f2>] nf_nat_cleanup_conntrack+0x42/0x70 [nf_nat]
RSP: 0018:ffff880202c63d40 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8801ac7bec28 RCX: ffff8801d0eedbe0
RDX: dead000000200200 RSI: 0000000000000011 RDI: ffffffffa03265b8
[..]
Call Trace:
[..]
[<ffffffffa02febed>] destroy_conntrack+0xbd/0x110 [nf_conntrack]
Happens when a conntrack timeout expires right after first part
of the nat cleanup has completed (bysrc hash removal), but before
part 2 has completed (re-initialization of nat area).
[ destroy callback tries to delete bysrc again ]
Patrick suggested to just remove the affected conntracks -- the
connections won't work properly anyway without nat transformation.
So, lets do that.
Reported-by: CAI Qian <caiqian@redhat.com>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
1 file changed