From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f79.google.com (mail-oo1-f79.google.com [209.85.161.79]) (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 7284238654F for ; Sat, 16 May 2026 22:06:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.79 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778969195; cv=none; b=AcD1OTAjkiOuXGE1l9YbwAhbL0sHVVMkPymRPI81DFuF2yGNzU53rR5Q/heKaCr/+2WvgxnUDrm7VHGWKsm6N787XpwGjqOVW8Gf0wD5ICI7/Ob6ktMRq2Hn3VzTYKglWRPvbwY8M2gBC6HnKW6v3hI/AZtE5jAllEfjUmuXZmQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778969195; c=relaxed/simple; bh=LQ+9u5KQTw3Qe4V1V0aVpJHbgudPG/BxPdJfTMzzs/I=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=diGE3I2klTkGIpxJRqahS6aqIeyhZ/MsOsfW8ssBjdjE4OMaklmefRnXdTuH0r7IsR1rbtg/NosoafV9E3ls1Opj/+BmPpsGdHrDgczlV0+hRagxKaBs/bUsfk4sBMJ40R0IfrIhdeBrdRHkDksa9PSrwP2pJvotoZ3WfREsyh8= 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=209.85.161.79 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-f79.google.com with SMTP id 006d021491bc7-6963482e03dso826813eaf.3 for ; Sat, 16 May 2026 15:06:33 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778969192; x=1779573992; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=+HDpYUYQUWYHmnaCi05DCcS4ksCaYX23ZoYkYWXPkU0=; b=fMAgRdFciZHAYdIeIR70TZr9hhXvkd5lfTBkfG0T3bnAki451rwTrpFpxApmpLVwTx C54CoEsQl0IFZkmQK6nh58cmqDUjg5rPZLzjtOoWQ0/6hoscbswEqQowunrIvGGOP42X BmF/saLvHMNBdndR8VzYamyae6wtfrn1PWkGmaW4xdpThllw1dTmjEqKibPNZlj5IW/l kNevWjJGyNDZhGH4i+nDmy9IcaEQZ8LnvObJov9kqYV4/+NTyxDSFCao19wPKCEr4jiP N7RUn4s+dAdP7x7xHDVidafvC/70Lo6kWQPOfC4I+By9ju+qIr0hYDSRMftSAuKa2KDl 8HXw== X-Forwarded-Encrypted: i=1; AFNElJ8lfsYtkNkMZ1SnMtJB/CCZdVcE1L07AEp7wSBQ4u3jqjGH32YkVbIRpiPe7ILbASNv+EKc2mmkRLQhaoA=@vger.kernel.org X-Gm-Message-State: AOJu0YwQv92D6eCauKm29kRZKTJTGgFCmvjTe2TI4JNeMf7nnaUk/uYX 8r6mbbRcsBCUHRjUGqbL6irrCwRKP9nvqe8QhPkkmCvF2ud0F+nHsop/M/mLc3uEs7gbovgzTKp eg1vSs+z8XN77FKN6WaFsU6FWxr0fYLEvQjDldzOfPlaQJ/0G3Hc04WX8VFw= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:c90:b0:694:99b7:1a2 with SMTP id 006d021491bc7-69c9435bcf0mr5714924eaf.22.1778969192411; Sat, 16 May 2026 15:06:32 -0700 (PDT) Date: Sat, 16 May 2026 15:06:32 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a08ea68.170a0220.1ad1c0.000f.GAE@google.com> Subject: [syzbot] [fs?] KCSAN: data-race in fill_mg_cmtime / inode_set_ctime_to_ts From: syzbot To: brauner@kernel.org, jack@suse.cz, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 6916d5703ddf Merge tag 'drm-fixes-2026-05-16' of https://g.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=164de8a6580000 kernel config: https://syzkaller.appspot.com/x/.config?x=2e40c0f41e01837e dashboard link: https://syzkaller.appspot.com/bug?extid=8091e831a26b0f999002 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/68f41c193b0d/disk-6916d570.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/b43a9332252c/vmlinux-6916d570.xz kernel image: https://storage.googleapis.com/syzbot-assets/6d9ea22a0feb/bzImage-6916d570.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+8091e831a26b0f999002@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in fill_mg_cmtime / inode_set_ctime_to_ts write to 0xffff888103f6ee90 of 8 bytes by task 9889 on cpu 1: inode_set_ctime_to_ts+0x8f/0x170 fs/inode.c:2771 __simple_unlink fs/libfs.c:792 [inline] simple_unlink+0x38/0x80 fs/libfs.c:807 shmem_unlink+0x12d/0x140 mm/shmem.c:3981 vfs_unlink+0x1c7/0x490 fs/namei.c:5498 filename_unlinkat+0x1e2/0x410 fs/namei.c:5568 __do_sys_unlink fs/namei.c:5603 [inline] __se_sys_unlink+0x2b/0xe0 fs/namei.c:5600 __x64_sys_unlink+0x1f/0x30 fs/namei.c:5600 x64_sys_call+0x2eb6/0x3020 arch/x86/include/generated/asm/syscalls_64.h:88 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 0xffff888103f6ee90 of 8 bytes by task 3291 on cpu 0: fill_mg_cmtime+0x86/0x240 fs/stat.c:56 generic_fillattr+0x24a/0x340 fs/stat.c:99 shmem_getattr+0x181/0x200 mm/shmem.c:1302 vfs_getattr_nosec+0x146/0x1e0 fs/stat.c:213 vfs_getattr+0x48/0x60 fs/stat.c:262 vfs_statx_path+0x28/0x140 fs/stat.c:299 vfs_statx+0xc4/0x170 fs/stat.c:356 vfs_fstatat+0x118/0x170 fs/stat.c:373 __do_sys_newfstatat fs/stat.c:538 [inline] __se_sys_newfstatat+0x55/0x3e0 fs/stat.c:532 __x64_sys_newfstatat+0x55/0x70 fs/stat.c:532 x64_sys_call+0x2c64/0x3020 arch/x86/include/generated/asm/syscalls_64.h:263 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 value changed: 0x0000000077359407 -> 0x0000000077359408 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 3291 Comm: udevd Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN 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