From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f78.google.com (mail-oa1-f78.google.com [209.85.160.78]) (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 D8F9036606A for ; Thu, 21 May 2026 22:56:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.78 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779404183; cv=none; b=iR45BJLmcC0TAAIu98KDnBIOctwJSvsO8JatJ48LVGAjeLVTeFgRgl8HV8a9NXTU6altp0UC1+f+ZJJI6m8AS51d80KJMU+BMsCW/VSU0rqALA+5hBuvhJhjmTq8LOZASyZv8iSm6nxW0iXcRR/h9R5NEqqTblUmfGlOGWSiIDM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779404183; c=relaxed/simple; bh=woFJNG+AkIhIjdrUa3L5vqm1iAVDH/ulwz2H+d6Dlac=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=EFsCk9fy3Xe1Q/RHBWHNDVF3uHZTMsaU/Wu3i9H09FZiHSL3Ts4k1sasJslqIzbin0qr2LufTBW6Sen+n8LYW4NRqYyP2wvy9odBFXe9P6HWh9Fb1dm3eRHBFyGStuMycQWfJ5LKKLc1gRY2ADLHp5lgA5hHYtYzY/5+uSFNY9g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.160.78 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oa1-f78.google.com with SMTP id 586e51a60fabf-4346755f7dcso12229601fac.3 for ; Thu, 21 May 2026 15:56:21 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779404181; x=1780008981; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=wKcggRR9OaSzW53BRXT7XgtoSulSO0zV7NnoewwOLLk=; b=qkyUX1Vg8vCLBHMsdr2GrxC9+nBxDRu2CDVxU88ccawIJq/LIZ13xny42o6zyI10y9 dZGuEwUfR4DyUwYBC7ji5D8KLy83ldj9NyEtMYUGIwnjgFpbwGR204A7nukMr2au97Qi YcgGPe+MwOgyczXsSUEM+rWx1ezAHLZ6ZMc+EqnP4vTKkWGpXaQERDa4NO3awcv8N6P5 ggugtqY+KZ/9+SduOVn6eedxS2Rr0P45YUjmfz+CpCynZbk1EnupTz4aUT+PAuyD18Zp gA0xOZe/mp7KfteB6HnI2unoi+jbPJPj94pwY0zRw54D1xTA/qUaulDg3aa7y1afKVBx VF4Q== X-Forwarded-Encrypted: i=1; AFNElJ8gQzR9I1wRq9/AusSlfBbuKM9yoJ8EmssIwGSwvoAuibQMufT6QKYBG+3/0QrFTKUmOwBJ9UQ=@vger.kernel.org X-Gm-Message-State: AOJu0YzLL0ZL91j6n8Br8YC0Y0Wlx8qjmgxP6xJpqzH9YnvakusdfD1U fS8YLwwkLi+OkRT8YJCF4EQ/mdZzfCFYz//AsVu9ZL3wHJHD43WxO9Sytqf52ae09r2QI/Ozoi0 xn78RUp1MbM6byZqiY2t2fHc5/4SkQVq3XYRHmeJlHvipcMsNt8virn74rv0= Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:998:b0:69d:7dbc:19b1 with SMTP id 006d021491bc7-69d7ed29503mr687622eaf.55.1779404180791; Thu, 21 May 2026 15:56:20 -0700 (PDT) Date: Thu, 21 May 2026 15:56:20 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a0f8d94.050a0220.6b33c.0000.GAE@google.com> Subject: [syzbot] [rds?] KCSAN: data-race in rds_poll / rds_sendmsg From: syzbot To: achender@kernel.org, allison.henderson@oracle.com, davem@davemloft.net, edumazet@google.com, horms@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, rds-devel@oss.oracle.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: e5d505e3664b Merge tag 'trace-v7.1-rc3' of git://git.kerne.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=144d37ba580000 kernel config: https://syzkaller.appspot.com/x/.config?x=2e40c0f41e01837e dashboard link: https://syzkaller.appspot.com/bug?extid=fbf3648ae7f5bdb05c59 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/d01e24b29d85/disk-e5d505e3.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/763a9ed109de/vmlinux-e5d505e3.xz kernel image: https://storage.googleapis.com/syzbot-assets/aa1f01135fd4/bzImage-e5d505e3.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+fbf3648ae7f5bdb05c59@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in rds_poll / rds_sendmsg write to 0xffff8881054183a4 of 4 bytes by task 9010 on cpu 0: rds_sendmsg+0x1001/0x15b0 net/rds/send.c:1391 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x563/0x5b0 net/socket.c:2698 ___sys_sendmsg+0x195/0x1e0 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2787 x64_sys_call+0x194c/0x3020 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff8881054183a4 of 4 bytes by task 9013 on cpu 1: rds_poll+0x9b/0x310 net/rds/af_rds.c:222 sock_poll+0x21c/0x240 net/socket.c:1502 vfs_poll include/linux/poll.h:82 [inline] __io_arm_poll_handler+0x1ef/0xbf0 io_uring/poll.c:590 io_arm_apoll+0x2eb/0x400 io_uring/poll.c:698 io_arm_poll_handler+0x12f/0x160 io_uring/poll.c:727 io_queue_async+0x25d/0x320 io_uring/io_uring.c:1634 io_queue_sqe io_uring/io_uring.c:1660 [inline] io_req_task_submit+0x9b/0xa0 io_uring/io_uring.c:1062 io_handle_tw_list+0x1f5/0x230 io_uring/tw.c:72 tctx_task_work_run+0x42/0x140 io_uring/tw.c:132 tctx_task_work+0x3f/0x80 io_uring/tw.c:150 task_work_run+0x130/0x1a0 kernel/task_work.c:233 get_signal+0xdea/0xf20 kernel/signal.c:2809 arch_do_signal_or_restart+0x96/0x480 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x6f/0x820 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x232/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00000000 -> 0x00000001 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 9013 Comm: syz.7.10555 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup