From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f77.google.com (mail-oo1-f77.google.com [209.85.161.77]) (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 EB93A239E9B for ; Fri, 6 Feb 2026 06:16:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.77 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770358586; cv=none; b=XjxSWgAuWir6RPXjYsbLbDnU99o7qYOaUvVjafo9G0dMgijI9MNqLcrGY78xHIKIp5hste0kgeJ20gLykVsf8yILgqxchlfHEc7wi0B5M3yQu390oXySbXw4aztxi07Gv5vZ4ueT+mzi3CCjjtHIp9xlII8DzzThyHJr83r/dDM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770358586; c=relaxed/simple; bh=4sW91DONuEZ2nAmyynltCSmDCpZ5X/Jb4bSRstGCYfM=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=Tjkvl3j3nmK/BadYZcjyaliw9d5XGa9fzNrp9UoDfhQ580ifD+ZPvEUu7n2e/fsSusrzmRQjGFri4RSPhTm6uh5e8HR4nHjjS+94EPBqYxMyzSBCwJZgvwana0soxeZgIkC+59LXUSR6kXp4CrJwHQlKwq/wXld8yinBfI1+7Ss= 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=209.85.161.77 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-oo1-f77.google.com with SMTP id 006d021491bc7-66b70fffe1dso7248536eaf.2 for ; Thu, 05 Feb 2026 22:16:25 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770358585; x=1770963385; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=Qix4/FgbsiFhyzHPSg9byFXxtny+dN9gBCfI2BW8FMY=; b=fMd5qIzPQPKCkjUljnDFEY5Lj2UBb0r2w5sAOKYoU+8xQVXNKRhitkS+2X7x4SVk0o uiV6yuoEIHOJ39o9ugZ6Rvs/7hLRkVPlrWQY2M1rmvaBMC/2qLVi4tVDz4munaTHp84+ PeO9PaebPING5jj4VAo1E8sCmgpQZVMaz57LIG886zDNnCmxkj34v5WUpNVCN81tds/m 8hHuafLT4a+3/LmUBKqdi6EqdPXS8qMmCenzexfsy1RCA4MunnjtZWqC9F/kmKqZs31l mfQxz8RnYIuejEVW/Deqh+14V/LvR9Sr29aiWTztsU2o7NPH8jVtlgAqOD5TrhmYo/To E8Fw== X-Forwarded-Encrypted: i=1; AJvYcCU7MV6/7WUzgVEmx6BK7hNRkWmPuR96j1kTJ8vEhb3dCtk0/Pug0xmXV0vTreHNW+A+XuFIbqE=@vger.kernel.org X-Gm-Message-State: AOJu0YwEG3O2MBoobiE/O+Q/azDNM87QrYNLnVR/na4M96L/Z9LmPXTF WvwOsBhPw3unhos8YTWFNwS24hqAbw7hgeCUr0wfHG+ZZaQ2Ytj61dUV6OCAIGHGu7Cm/U8d0Qq OUBP2Kac2HDK2up2877oA508z6IE6Kmw3T6ySbWhe+pQTtvl7LgexO1ELXY8= Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:4de8:b0:659:9a49:8eaa with SMTP id 006d021491bc7-66d0bf9e128mr808995eaf.46.1770358584945; Thu, 05 Feb 2026 22:16:24 -0800 (PST) Date: Thu, 05 Feb 2026 22:16:24 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69858738.050a0220.3b3015.002e.GAE@google.com> Subject: [syzbot] [smc?] KCSAN: data-race in smc_switch_to_fallback / sock_poll (2) From: syzbot To: alibuda@linux.alibaba.com, davem@davemloft.net, dust.li@linux.alibaba.com, edumazet@google.com, guwen@linux.alibaba.com, horms@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, linux-s390@vger.kernel.org, mjambigi@linux.ibm.com, netdev@vger.kernel.org, pabeni@redhat.com, sidraya@linux.ibm.com, syzkaller-bugs@googlegroups.com, tonylu@linux.alibaba.com, wenjia@linux.ibm.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 5fd0a1df5d05 Merge tag 'v6.19rc8-smb3-client-fixes' of git.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1070aa5a580000 kernel config: https://syzkaller.appspot.com/x/.config?x=8e27f4588a0f2183 dashboard link: https://syzkaller.appspot.com/bug?extid=198c20fde37cb9f6b0ac 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/a09cd69509c3/disk-5fd0a1df.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/f218ec1eb157/vmlinux-5fd0a1df.xz kernel image: https://storage.googleapis.com/syzbot-assets/8549229eee91/bzImage-5fd0a1df.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+198c20fde37cb9f6b0ac@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in smc_switch_to_fallback / sock_poll write to 0xffff888127398c18 of 8 bytes by task 14369 on cpu 1: smc_switch_to_fallback+0x4ea/0x7e0 net/smc/af_smc.c:933 smc_sendmsg+0xce/0x2f0 net/smc/af_smc.c:2797 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0x5af/0x600 net/socket.c:2592 ___sys_sendmsg+0x195/0x1e0 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2681 x64_sys_call+0x17ba/0x3000 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff888127398c18 of 8 bytes by task 14367 on cpu 0: sock_poll+0x27/0x240 net/socket.c:1427 vfs_poll include/linux/poll.h:82 [inline] __io_arm_poll_handler+0x1ee/0xb80 io_uring/poll.c:581 io_poll_add+0x69/0xf0 io_uring/poll.c:899 __io_issue_sqe+0xfd/0x2d0 io_uring/io_uring.c:1793 io_issue_sqe+0x20b/0xc20 io_uring/io_uring.c:1816 io_queue_sqe io_uring/io_uring.c:2043 [inline] io_submit_sqe io_uring/io_uring.c:2321 [inline] io_submit_sqes+0x78a/0x11b0 io_uring/io_uring.c:2435 __do_sys_io_uring_enter io_uring/io_uring.c:3285 [inline] __se_sys_io_uring_enter+0x1bf/0x1c70 io_uring/io_uring.c:3224 __x64_sys_io_uring_enter+0x78/0x90 io_uring/io_uring.c:3224 x64_sys_call+0x27e4/0x3000 arch/x86/include/generated/asm/syscalls_64.h:427 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0xffff88811a6056c0 -> 0xffff88811a606080 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 14367 Comm: syz.8.3658 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 ================================================================== --- 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