From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f206.google.com (mail-il1-f206.google.com [209.85.166.206]) (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 39097260A26 for ; Tue, 25 Feb 2025 10:36:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.206 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740479792; cv=none; b=a1BFGgPX/znJqYD1yrYOWNPPyivLa56gfogT5DTtg9i+fPvttw2I+UVmFEFPKZ8PuwXwMc6qHCDMERyer1f5ylG4ppVKd/A+NkMnhGKi+0b+qtsKsm+NO+JXWq+d+RUR21EA7Nbi84HUDvsOGsMCOaUxXlpDr3riOz+Pi3+HAKw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740479792; c=relaxed/simple; bh=XjsAgpsN0j5oRHDKfW6dWsYs0oKQaUu98fmWODDFbQs=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=Ck/FbSPtC+pXnicm1tLimUXN+ZrGg7X6Evm0A0PDJ+6b5z2csm+FLfWLKboxLx3SYvjVnvVyglPY3HC+uUoInv7CLsyKWMlQLDOMfTjZ8QUbdVC/bIfSb38j6etiv910Zt8I9tbezy0IpWkzu4JLTJgwVuJPwDJRc8r+afY/ibA= 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=209.85.166.206 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-il1-f206.google.com with SMTP id e9e14a558f8ab-3d2a40e470fso42345475ab.3 for ; Tue, 25 Feb 2025 02:36:30 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740479790; x=1741084590; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=itkP3+EqX5jDHrJ5nqo1dq9K7WbkKJPEFcpMjPBhsv4=; b=wNJtye8/OPxREbs4WHCdy/utnB1jZMyhCavil3g8SlgHN71BUVcO6ziOWiSZ2Q0wXi JhX+To/uuLH0ZBDL/Rmi78xzfjFQstZlq0YXpMuERPnABWE5NK5FFBmllsvr1lzbXPBA gejkhc7jPs6QZ3VGRJ1wF9F6wcY9048StQknkINxnRxthQNn1Eo8LyisPQCPKSUPq5Hh OINLcxvZwgfENrD8CESFbVQWxQnEZ5uhm5/w2XAmf439hdaQnIq3jpjwqLoSWlRCrOS2 QyvmUN6et3jxtAqo/1SGqOoCozzZmEpWXRGNTivB7m0V5Io5uWYQ6GTFIQo6mv7nMWUj /Xfw== X-Forwarded-Encrypted: i=1; AJvYcCUdk4P7YZIf6mRPxgtkFynp8jnczOG/E93nvoQc4Z3s+SJCKVxJgfjt6w6aV/ODuS2oS+fUNtu+FSNRTN4=@vger.kernel.org X-Gm-Message-State: AOJu0YzOlc8esZuD2AZkmMVWbhmgpaDFLTLdsLT/rVixntdQ1W31cxfI NQeUjwsekBubi+sxU5pw57MHBN9wEpfwXMTi0LvxjesHDQE1UvrX8ucPnmMA+AgWV/7F02uFZeS YDRwMTc2vhVPkiIwNm0fez0/RtpcPduK3kw6VyoZnLe1D3ptVQLhDbEY= X-Google-Smtp-Source: AGHT+IFbCtGYN61vjgMvuKY9FqO2iFg0X/7ZT3gxl6WR+kyIz5LfL7pn902vPL7OLDRZM32Vw31ljX1b8mS3lYQ1iGrVPm6ofRIE Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:1f04:b0:3cf:b87b:8fde with SMTP id e9e14a558f8ab-3d2caefdc5cmr154864735ab.17.1740479790345; Tue, 25 Feb 2025 02:36:30 -0800 (PST) Date: Tue, 25 Feb 2025 02:36:30 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <67bd9d2e.050a0220.bbfd1.00a5.GAE@google.com> Subject: [syzbot] [netfs?] KCSAN: data-race in netfs_advance_write / netfs_write_collection_worker From: syzbot To: dhowells@redhat.com, jlayton@kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, netfs@lists.linux.dev, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: d082ecbc71e9 Linux 6.14-rc4 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=130277f8580000 kernel config: https://syzkaller.appspot.com/x/.config?x=e9dd6c7eeba2114e dashboard link: https://syzkaller.appspot.com/bug?extid=912f708269025e337cba compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/2b352c2abb77/disk-d082ecbc.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/c5f4a062a264/vmlinux-d082ecbc.xz kernel image: https://storage.googleapis.com/syzbot-assets/c3a86625df5a/bzImage-d082ecbc.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+912f708269025e337cba@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in netfs_advance_write / netfs_write_collection_worker write to 0xffff8881188765b8 of 8 bytes by task 3523 on cpu 0: netfs_prepare_write fs/netfs/write_issue.c:210 [inline] netfs_advance_write+0x36f/0x610 fs/netfs/write_issue.c:298 netfs_unbuffered_write+0xde/0x330 fs/netfs/write_issue.c:721 netfs_unbuffered_write_iter_locked+0x2b7/0x570 fs/netfs/direct_write.c:100 netfs_unbuffered_write_iter+0x2b7/0x3b0 fs/netfs/direct_write.c:195 v9fs_file_write_iter+0x60/0x80 fs/9p/vfs_file.c:404 new_sync_write fs/read_write.c:586 [inline] vfs_write+0x77b/0x920 fs/read_write.c:679 ksys_write+0xe8/0x1b0 fs/read_write.c:731 __do_sys_write fs/read_write.c:742 [inline] __se_sys_write fs/read_write.c:739 [inline] __x64_sys_write+0x42/0x50 fs/read_write.c:739 x64_sys_call+0x287e/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff8881188765b8 of 8 bytes by task 50 on cpu 1: netfs_collect_write_results fs/netfs/write_collect.c:231 [inline] netfs_write_collection_worker+0x3ee/0x2530 fs/netfs/write_collect.c:374 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0x4db/0xa20 kernel/workqueue.c:3317 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3398 kthread+0x4ae/0x520 kernel/kthread.c:464 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 value changed: 0x0000000000000000 -> 0xffff888103259900 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 50 Comm: kworker/u8:3 Not tainted 6.14.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound netfs_write_collection_worker ================================================================== --- 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