From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6AFF4C433F5 for ; Wed, 23 Feb 2022 20:10:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234940AbiBWUKm (ORCPT ); Wed, 23 Feb 2022 15:10:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42054 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234567AbiBWUKm (ORCPT ); Wed, 23 Feb 2022 15:10:42 -0500 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A58C4C7AD for ; Wed, 23 Feb 2022 12:10:12 -0800 (PST) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1nMxxh-0008Rj-OQ; Wed, 23 Feb 2022 21:10:09 +0100 From: Florian Westphal To: Cc: Florian Westphal Subject: [PATCH nf] netfilter: nf_queue: don't assume sk is full socket Date: Wed, 23 Feb 2022 21:10:04 +0100 Message-Id: <20220223201004.30615-1-fw@strlen.de> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org There is no guarantee that state->sk refers to a full socket. If refcount transitions to 0, sock_put calls sk_free which then ends up with garbage fields. I'd like to thank Oleksandr Natalenko and Jiri Benc for considerable debug work and pointing out state->sk oddities. Fixes: ca6fb0651883 ("tcp: attach SYNACK messages to request sockets instead of listener") Signed-off-by: Florian Westphal --- No reproducer, so there is a chance that the reported crash is caused by something else. That said, I don't see how sock_put use is safe here. net/netfilter/nf_queue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c index 6d12afabfe8a..178742a110d9 100644 --- a/net/netfilter/nf_queue.c +++ b/net/netfilter/nf_queue.c @@ -54,7 +54,7 @@ static void nf_queue_entry_release_refs(struct nf_queue_entry *entry) dev_put(state->in); dev_put(state->out); if (state->sk) - sock_put(state->sk); + sock_gen_put(state->sk); #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) dev_put(entry->physin); -- 2.34.1