From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2700315AD3 for ; Wed, 20 Sep 2023 12:38:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E71DC433CA; Wed, 20 Sep 2023 12:38:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1695213502; bh=BEFJ/26C2aFWz3c77jQwiD1wPfMojvoTJIk9FGTHfKw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KAcxu6pE682P/p8LNcDb67TgLAqVkusUmYcFt93ZJbrT9S803BAwbZkclxfk1gjMt yYEyGucUQ7Ot8xLQnrh9GxZKoLH+XofZfionU3sBnAYsqhicWL+tp+cHsNba0ABcZ8 zT+vxULGOfqg+hkZk8l15RShvOb9T9LSivk3YXNU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot , Eric Dumazet , Kuniyuki Iwashima , Paolo Abeni , Sasha Levin Subject: [PATCH 5.4 260/367] net: read sk->sk_family once in sk_mc_loop() Date: Wed, 20 Sep 2023 13:30:37 +0200 Message-ID: <20230920112905.293027465@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230920112858.471730572@linuxfoundation.org> References: <20230920112858.471730572@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit a3e0fdf71bbe031de845e8e08ed7fba49f9c702c ] syzbot is playing with IPV6_ADDRFORM quite a lot these days, and managed to hit the WARN_ON_ONCE(1) in sk_mc_loop() We have many more similar issues to fix. WARNING: CPU: 1 PID: 1593 at net/core/sock.c:782 sk_mc_loop+0x165/0x260 Modules linked in: CPU: 1 PID: 1593 Comm: kworker/1:3 Not tainted 6.1.40-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Workqueue: events_power_efficient gc_worker RIP: 0010:sk_mc_loop+0x165/0x260 net/core/sock.c:782 Code: 34 1b fd 49 81 c7 18 05 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 ff e8 25 36 6d fd 4d 8b 37 eb 13 e8 db 33 1b fd <0f> 0b b3 01 eb 34 e8 d0 33 1b fd 45 31 f6 49 83 c6 38 4c 89 f0 48 RSP: 0018:ffffc90000388530 EFLAGS: 00010246 RAX: ffffffff846d9b55 RBX: 0000000000000011 RCX: ffff88814f884980 RDX: 0000000000000102 RSI: ffffffff87ae5160 RDI: 0000000000000011 RBP: ffffc90000388550 R08: 0000000000000003 R09: ffffffff846d9a65 R10: 0000000000000002 R11: ffff88814f884980 R12: dffffc0000000000 R13: ffff88810dbee000 R14: 0000000000000010 R15: ffff888150084000 FS: 0000000000000000(0000) GS:ffff8881f6b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000180 CR3: 000000014ee5b000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: [] ip6_finish_output2+0x33f/0x1ae0 net/ipv6/ip6_output.c:83 [] __ip6_finish_output net/ipv6/ip6_output.c:200 [inline] [] ip6_finish_output+0x6c6/0xb10 net/ipv6/ip6_output.c:211 [] NF_HOOK_COND include/linux/netfilter.h:298 [inline] [] ip6_output+0x2bc/0x3d0 net/ipv6/ip6_output.c:232 [] dst_output include/net/dst.h:444 [inline] [] ip6_local_out+0x10f/0x140 net/ipv6/output_core.c:161 [] ipvlan_process_v6_outbound drivers/net/ipvlan/ipvlan_core.c:483 [inline] [] ipvlan_process_outbound drivers/net/ipvlan/ipvlan_core.c:529 [inline] [] ipvlan_xmit_mode_l3 drivers/net/ipvlan/ipvlan_core.c:602 [inline] [] ipvlan_queue_xmit+0x1174/0x1be0 drivers/net/ipvlan/ipvlan_core.c:677 [] ipvlan_start_xmit+0x49/0x100 drivers/net/ipvlan/ipvlan_main.c:229 [] netdev_start_xmit include/linux/netdevice.h:4925 [inline] [] xmit_one net/core/dev.c:3644 [inline] [] dev_hard_start_xmit+0x320/0x980 net/core/dev.c:3660 [] sch_direct_xmit+0x2a0/0x9c0 net/sched/sch_generic.c:342 [] qdisc_restart net/sched/sch_generic.c:407 [inline] [] __qdisc_run+0xb13/0x1e70 net/sched/sch_generic.c:415 [] qdisc_run+0xd6/0x260 include/net/pkt_sched.h:125 [] net_tx_action+0x7ac/0x940 net/core/dev.c:5247 [] __do_softirq+0x2bd/0x9bd kernel/softirq.c:599 [] invoke_softirq kernel/softirq.c:430 [inline] [] __irq_exit_rcu+0xc8/0x170 kernel/softirq.c:683 [] irq_exit_rcu+0x9/0x20 kernel/softirq.c:695 Fixes: 7ad6848c7e81 ("ip: fix mc_loop checks for tunnels with multicast outer addresses") Reported-by: syzbot Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://lore.kernel.org/r/20230830101244.1146934-1-edumazet@google.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/core/sock.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/core/sock.c b/net/core/sock.c index 69b4158a29f74..1fed45f29e0ec 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -701,7 +701,8 @@ bool sk_mc_loop(struct sock *sk) return false; if (!sk) return true; - switch (sk->sk_family) { + /* IPV6_ADDRFORM can change sk->sk_family under us. */ + switch (READ_ONCE(sk->sk_family)) { case AF_INET: return inet_sk(sk)->mc_loop; #if IS_ENABLED(CONFIG_IPV6) -- 2.40.1