From nobody Thu Dec 25 18:03:10 2025 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C662D6BB57 for ; Fri, 12 Jan 2024 13:27:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="sUygNlSy" Received: by mail-yb1-f201.google.com with SMTP id 3f1490d57ef6-dbe9dacc912so7926872276.2 for ; Fri, 12 Jan 2024 05:27:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1705066021; x=1705670821; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=f93Ig9LJYi6SxdMZrbYZZHjHKOcib3L6QU/xnO4vU2I=; b=sUygNlSyCS5vY6Fk6MTb1dALHL9wYVw3GoCyPUx/hDpPatN0773TiQ5XqszcdpNVmv /fs9w1ONsQDFoy+fGNLRndio09a21H3GFteGWTdkvT2COxdPO+MVUscmXim5VRkGsgbq hdsNs/j1EJd2TN6zeqNVrsuBJnxGFiLRljVVz9WQ35m5if1Qb4Acn+tBBvZWqoU9LEd/ NoMtNRuuxpYiw826QdLA1v53r71GL2T/geoCcBiH3dlWMFW8cYWFkdCLuxzhWi4VRKfd nQVBtHncuyfGktgFuPSN0Z9CzDTcV+BlxYaMM1QuTfSX6G4FjAx9TZ3Ja8PbUqMeXhUs INRQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1705066021; x=1705670821; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=f93Ig9LJYi6SxdMZrbYZZHjHKOcib3L6QU/xnO4vU2I=; b=lc8tsOXn7OM6VpWxjf6Dl9VTpucnh2rymr6vHoXM5uLj2ZT4w03wUbomYO/QdguMVW MM7fDRDku+ZVgF4JB9mhiEPAA++MYZ1CkM2k9n1uKSADnA5r/wxuNYwOyvatu/awtZbF H9rNT3kIM9hQHBMKaAOK2FKG0lWyqONa78XET8GgxU671W34wzuUYeMcC/qpGYYEQ9l5 x8s82/a1HORmj76FjWofWv01Q/ZFg63SUKzQv5pvX6Hh52Q6CXhsFjgJfV0MMKW5vkUM SdZt0qfJCe6oUh0sG/XHp/FicEkSUi/+VfwEmtZDiE9eaDp7s5IparDoB2oyD+aowQRV bTbw== X-Gm-Message-State: AOJu0YwLy81bxHj+1YKRE+zLH91JGAzRmjhddw6bMbQAnW824t4YGMg9 e1a/ahPns9zFti5GLWhdjuFNsFs47ec96yuV+iNU X-Google-Smtp-Source: AGHT+IEdNpp9MV1efGqWVumTNO6v9b0Uyr5We6/Yz4ZyzAHpiTLmjWlQyhYuSCloT/e8oLsD+H1RgUnxsQqoUQ== X-Received: from edumazet1.c.googlers.com ([fda3:e722:ac3:cc00:2b:7d90:c0a8:395a]) (user=edumazet job=sendgmr) by 2002:a05:6902:2483:b0:dbd:73bd:e55a with SMTP id ds3-20020a056902248300b00dbd73bde55amr21536ybb.4.1705066020920; Fri, 12 Jan 2024 05:27:00 -0800 (PST) Date: Fri, 12 Jan 2024 13:26:57 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.43.0.275.g3460e3d667-goog Message-ID: <20240112132657.647112-1-edumazet@google.com> Subject: [PATCH net] nbd: always initialize struct msghdr completely From: Eric Dumazet To: Jens Axboe Cc: linux-kernel , netdev@vger.kernel.org, Eric Dumazet , Eric Dumazet , syzbot , stable@vger.kernel.org, Josef Bacik , linux-block@vger.kernel.org, nbd@other.debian.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" syzbot complains that msg->msg_get_inq value can be uninitialized [1] struct msghdr got many new fields recently, we should always make sure their values is zero by default. [1] BUG: KMSAN: uninit-value in tcp_recvmsg+0x686/0xac0 net/ipv4/tcp.c:2571 tcp_recvmsg+0x686/0xac0 net/ipv4/tcp.c:2571 inet_recvmsg+0x131/0x580 net/ipv4/af_inet.c:879 sock_recvmsg_nosec net/socket.c:1044 [inline] sock_recvmsg+0x12b/0x1e0 net/socket.c:1066 __sock_xmit+0x236/0x5c0 drivers/block/nbd.c:538 nbd_read_reply drivers/block/nbd.c:732 [inline] recv_work+0x262/0x3100 drivers/block/nbd.c:863 process_one_work kernel/workqueue.c:2627 [inline] process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2700 worker_thread+0xf45/0x1490 kernel/workqueue.c:2781 kthread+0x3ed/0x540 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Local variable msg created at: __sock_xmit+0x4c/0x5c0 drivers/block/nbd.c:513 nbd_read_reply drivers/block/nbd.c:732 [inline] recv_work+0x262/0x3100 drivers/block/nbd.c:863 CPU: 1 PID: 7465 Comm: kworker/u5:1 Not tainted 6.7.0-rc7-syzkaller-00041-g= f016f7547aee #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Goo= gle 11/17/2023 Workqueue: nbd5-recv recv_work Fixes: f94fd25cb0aa ("tcp: pass back data left in socket after receive") Reported-by: syzbot Signed-off-by: Eric Dumazet Cc: stable@vger.kernel.org Cc: Josef Bacik Cc: Jens Axboe Cc: linux-block@vger.kernel.org Cc: nbd@other.debian.org Reviewed-by: Simon Horman --- drivers/block/nbd.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 4e72ec4e25ac5a0f41bca299e7efaecf6503c451..33a8f37bb6a1f504060f783c6d7= 27e4c76026a2e 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -508,7 +508,7 @@ static int __sock_xmit(struct nbd_device *nbd, struct s= ocket *sock, int send, struct iov_iter *iter, int msg_flags, int *sent) { int result; - struct msghdr msg; + struct msghdr msg =3D {} ; unsigned int noreclaim_flag; =20 if (unlikely(!sock)) { @@ -524,10 +524,6 @@ static int __sock_xmit(struct nbd_device *nbd, struct = socket *sock, int send, do { sock->sk->sk_allocation =3D GFP_NOIO | __GFP_MEMALLOC; sock->sk->sk_use_task_frag =3D false; - msg.msg_name =3D NULL; - msg.msg_namelen =3D 0; - msg.msg_control =3D NULL; - msg.msg_controllen =3D 0; msg.msg_flags =3D msg_flags | MSG_NOSIGNAL; =20 if (send) --=20 2.43.0.275.g3460e3d667-goog