From nobody Fri Dec 19 18:53:46 2025 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 648F2156667; Sun, 24 Mar 2024 23:11:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711321873; cv=none; b=XZk4CEc7/ok0l2D1caDvnp2H8+6/+6lQLY0DznqRQquE1oHM7E7afn8tG7hFDgWhkFuL1BdvJs1JR0P1nP8dOcBme0GNbcHD0kInbBJCmUqU4xpyUW4qB12jnCdjTRAZiSM2gPS5WilNocBKpOmmZzw1FrLHc7Q/lcfSOIxmRrI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711321873; c=relaxed/simple; bh=AqqaowdoPjgLyl6nrMyijMdPdDNem1whp46PAG5TrTk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=m+7VXJ5SppgG/0s/e3AI1s+1IdubRD+hSBIH1k4O4Ty/bQqbzAPtXHcEr54n+Q9qCdIEm5dMVM+mIpQf14Q1gvB8O+JEbklfNbc8nu9v1GdDgkW31P+/Esnn96Bg50BLJTYAAJXjNqKkwBMgfF+FNV+3sukoTZdTy+VBKPqkanU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eWGaWWNw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eWGaWWNw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 142D0C433F1; Sun, 24 Mar 2024 23:11:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711321872; bh=AqqaowdoPjgLyl6nrMyijMdPdDNem1whp46PAG5TrTk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eWGaWWNwBYpLl3nMbnOqQCIMnt7NHWj+Zjt7/wDXaCva3WkKPXzxxrmVYGLigoF0D S6UU5l4S6Z9zcAMm1il9RVE7Cv5HgmgP6OZEIOBSBEQEiCcGW744BJagZyH0C/6sVU bmFuElAXF8+Db0Tlv+yHJu2MnpXbd0ae1lMqjepGIVUJ6bmZWM+/oPxWGGchQXtgvD edaV8/bHv/qDadJlF4xBwZfVlkHD2uN9iMt/MeAgdMoZRO3sW4fqQdRNUSEoIxvX4Q Oif43m1yBfBL1LnEZrB9aXa2YVLDUcQ4hFeq04SY7itY7JAxPFnkKDxipnVcYqxpkd MRikyNdH0YfDg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Dumazet , syzbot+c669c1136495a2e7c31f@syzkaller.appspotmail.com, Willem de Bruijn , Willem de Bruijn , Jason Xing , "David S . Miller" , Sasha Levin Subject: [PATCH 6.6 600/638] packet: annotate data-races around ignore_outgoing Date: Sun, 24 Mar 2024 19:00:37 -0400 Message-ID: <20240324230116.1348576-601-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324230116.1348576-1-sashal@kernel.org> References: <20240324230116.1348576-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Eric Dumazet [ Upstream commit 6ebfad33161afacb3e1e59ed1c2feefef70f9f97 ] ignore_outgoing is read locklessly from dev_queue_xmit_nit() and packet_getsockopt() Add appropriate READ_ONCE()/WRITE_ONCE() annotations. syzbot reported: BUG: KCSAN: data-race in dev_queue_xmit_nit / packet_setsockopt write to 0xffff888107804542 of 1 bytes by task 22618 on cpu 0: packet_setsockopt+0xd83/0xfd0 net/packet/af_packet.c:4003 do_sock_setsockopt net/socket.c:2311 [inline] __sys_setsockopt+0x1d8/0x250 net/socket.c:2334 __do_sys_setsockopt net/socket.c:2343 [inline] __se_sys_setsockopt net/socket.c:2340 [inline] __x64_sys_setsockopt+0x66/0x80 net/socket.c:2340 do_syscall_64+0xd3/0x1d0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 read to 0xffff888107804542 of 1 bytes by task 27 on cpu 1: dev_queue_xmit_nit+0x82/0x620 net/core/dev.c:2248 xmit_one net/core/dev.c:3527 [inline] dev_hard_start_xmit+0xcc/0x3f0 net/core/dev.c:3547 __dev_queue_xmit+0xf24/0x1dd0 net/core/dev.c:4335 dev_queue_xmit include/linux/netdevice.h:3091 [inline] batadv_send_skb_packet+0x264/0x300 net/batman-adv/send.c:108 batadv_send_broadcast_skb+0x24/0x30 net/batman-adv/send.c:127 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:392 [inline] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:420 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x3f0/0x4b0 net/batman-adv/bat_i= v_ogm.c:1700 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335 worker_thread+0x526/0x730 kernel/workqueue.c:3416 kthread+0x1d1/0x210 kernel/kthread.c:388 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 value changed: 0x00 -> 0x01 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 27 Comm: kworker/u8:1 Tainted: G W 6.8.0-syzkal= ler-08073-g480e035fc4c7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Goo= gle 02/29/2024 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Fixes: fa788d986a3a ("packet: add sockopt to ignore outgoing packets") Reported-by: syzbot+c669c1136495a2e7c31f@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/CANn89i+Z7MfbkBLOv=3Dp7KZ7=3DK1rKHO4= P1OL5LYDCtBiyqsa9oQ@mail.gmail.com/T/#t Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Reviewed-by: Willem de Bruijn Reviewed-by: Jason Xing Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/core/dev.c | 2 +- net/packet/af_packet.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index d72a4ff689ca7..8ac8b5c561030 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2290,7 +2290,7 @@ void dev_queue_xmit_nit(struct sk_buff *skb, struct n= et_device *dev) rcu_read_lock(); again: list_for_each_entry_rcu(ptype, ptype_list, list) { - if (ptype->ignore_outgoing) + if (READ_ONCE(ptype->ignore_outgoing)) continue; =20 /* Never send packets back to the socket diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 7adf48549a3b7..f017d7d33da39 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -4004,7 +4004,7 @@ packet_setsockopt(struct socket *sock, int level, int= optname, sockptr_t optval, if (val < 0 || val > 1) return -EINVAL; =20 - po->prot_hook.ignore_outgoing =3D !!val; + WRITE_ONCE(po->prot_hook.ignore_outgoing, !!val); return 0; } case PACKET_TX_HAS_OFF: @@ -4135,7 +4135,7 @@ static int packet_getsockopt(struct socket *sock, int= level, int optname, 0); break; case PACKET_IGNORE_OUTGOING: - val =3D po->prot_hook.ignore_outgoing; + val =3D READ_ONCE(po->prot_hook.ignore_outgoing); break; case PACKET_ROLLOVER_STATS: if (!po->rollover) --=20 2.43.0