From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f207.google.com (mail-il1-f207.google.com [209.85.166.207]) (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 708481DF258 for ; Fri, 13 Jun 2025 23:32:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.207 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749857553; cv=none; b=puJUePkOnhU3tJ2zXrkY1USHziOL/zzmdPgeBYYjxwvuCbE0xftz5nMTgzc5h0oTil9zVhSHo4gOHsizqjX5oHf6sdhyJ1BRN6N/WZUMS/FGRhn3dGJ3kmk2GxcRn+DSG4ZhENwnm8C+uG8jHlr8D8r2Vd1C6oQsNA8wCCG/ync= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749857553; c=relaxed/simple; bh=UDqaCvAIdirfawmGp34dqRheS5JfCbkZZ8jW7eT1xDA=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=IPSGs0tedZjWYnPyar34NcV+hkGDF3PnXnYK92gyuJFS69U+oflBNyro5LqFHPlD8tYGFaTL3Mg/RW96B9y/rtvdDsHl3ytznmljrT8ITV+2pKHhWqs8OpX7JZPA29nlZIubppHueQwmPaIw3EK/zfcNibqUcoSFjq+1kNXW2nQ= 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=209.85.166.207 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-f207.google.com with SMTP id e9e14a558f8ab-3ddc5137992so30227485ab.2 for ; Fri, 13 Jun 2025 16:32:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749857550; x=1750462350; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=CGrDk590oj5l4YMCQPrjJdpXxax7r8Aqn6OXYAddFc8=; b=AM6CNHzR+m2x5JR5KOpy0INV8A8g/7c+IyT3y6qC0EytDblwQk+bR4e6eVQXm8Hs4a Q7kOo5xyg57yRJ8oNBcVR+PN2A1D44LBYlcxnx4VRHBlI9EudAvxTMq33vaSiDX3z6U6 VtICpHg2z+YrIH4eOYfCyYukHCUvfyB1KvG6RPX5BMovI+z7+JI4VD8vZrPkeIfmaBzw r0MXhnvnaCOSvYJWULnGn//fwtPJbb1uBtwgziFAsUGPNprowkNtRffzNWcFmG7e+Cvv PmsPR2RpbDEpipoXgDrMbkZS7R999cCGb0ColWvThNCGv1+YCO9AC6Fbc3ve8INZ8a+O kK+Q== X-Forwarded-Encrypted: i=1; AJvYcCXToRyGTHIIDMDaCxTKUIT/mCAsbWXzyCjffjd5PM3VYFdbHY/0a52Uc9b8n2HUR94qBs8LWSWjslJ1AL4=@vger.kernel.org X-Gm-Message-State: AOJu0Ywc9t9YGUxX5Z5ho3EqmXg+IJGxemAGxwWeVQ0ZdgGHlJzdyBLV Wm0IiDcM2OndsT74uMLIhd7cqDRuB28SW6hBtaHf79HYASJDQfuD9z4aD1XH9mehHrEl+BQE1Q6 D8CSWnIGOc1P2tClLI+5FHalit7KafBiJipW2Cpt/YGX/dQeRBkclAvkpxg0= X-Google-Smtp-Source: AGHT+IHGbocCoWkDDO+t3uXpA2pWI1xImojiPlt7aYrdXlY4jZ0GM7N7S0M+v5LezbxL5CqFjRTTVkXtH0QcqiC46/BZl/bNjUqa Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:160b:b0:3dd:bb7e:f1af with SMTP id e9e14a558f8ab-3de07cedfc2mr17993855ab.20.1749857550693; Fri, 13 Jun 2025 16:32:30 -0700 (PDT) Date: Fri, 13 Jun 2025 16:32:30 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <684cb50e.a00a0220.279073.0019.GAE@google.com> Subject: [syzbot] [kernfs?] possible deadlock in mnt_want_write (6) From: syzbot To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, tj@kernel.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 475c850a7fdd Add linux-next specific files for 20250606 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=17aea9d4580000 kernel config: https://syzkaller.appspot.com/x/.config?x=28859360c84ac63d dashboard link: https://syzkaller.appspot.com/bug?extid=a16a4917cc8df9582272 compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/2f1cf8485b7a/disk-475c850a.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/976adb9f739e/vmlinux-475c850a.xz kernel image: https://storage.googleapis.com/syzbot-assets/0ac20b1308b7/bzImage-475c850a.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+a16a4917cc8df9582272@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected 6.15.0-next-20250606-syzkaller #0 Not tainted ------------------------------------------------------ syz.1.1351/13335 is trying to acquire lock: ffff888035b3c428 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557 but task is already holding lock: ffff888059674100 (&ovl_i_mutex_dir_key[depth]#2){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] ffff888059674100 (&ovl_i_mutex_dir_key[depth]#2){++++}-{4:4}, at: open_last_lookups fs/namei.c:3804 [inline] ffff888059674100 (&ovl_i_mutex_dir_key[depth]#2){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4043 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&ovl_i_mutex_dir_key[depth]#2){++++}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1524 inode_lock_shared include/linux/fs.h:882 [inline] lookup_slow+0x46/0x70 fs/namei.c:1833 walk_component+0x2d2/0x400 fs/namei.c:2138 lookup_last fs/namei.c:2639 [inline] path_lookupat+0x163/0x430 fs/namei.c:2663 filename_lookup+0x212/0x570 fs/namei.c:2692 kern_path+0x35/0x50 fs/namei.c:2825 lookup_bdev+0xc0/0x280 block/bdev.c:1205 resume_store+0x169/0x460 kernel/power/hibernate.c:1272 kernfs_fop_write_iter+0x378/0x4f0 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x54b/0xa90 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&of->mutex){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 iter_file_splice_write+0x937/0x1000 fs/splice.c:738 do_splice_from fs/splice.c:935 [inline] do_splice+0xc79/0x1660 fs/splice.c:1348 __do_splice fs/splice.c:1430 [inline] __do_sys_splice fs/splice.c:1633 [inline] __se_sys_splice+0x2e1/0x460 fs/splice.c:1615 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&pipe->mutex){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 iter_file_splice_write+0x1e6/0x1000 fs/splice.c:683 do_splice_from fs/splice.c:935 [inline] do_splice+0xc79/0x1660 fs/splice.c:1348 __do_splice fs/splice.c:1430 [inline] __do_sys_splice fs/splice.c:1633 [inline] __se_sys_splice+0x2e1/0x460 fs/splice.c:1615 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (sb_writers#5){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs.h:1793 [inline] sb_start_write+0x4d/0x1c0 include/linux/fs.h:1929 mnt_want_write+0x41/0x90 fs/namespace.c:557 ovl_create_object+0xfc/0x310 fs/overlayfs/dir.c:628 lookup_open fs/namei.c:3708 [inline] open_last_lookups fs/namei.c:3807 [inline] path_openat+0x14f1/0x3830 fs/namei.c:4043 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_creat fs/open.c:1530 [inline] __se_sys_creat fs/open.c:1524 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1524 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: sb_writers#5 --> &of->mutex --> &ovl_i_mutex_dir_key[depth]#2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ovl_i_mutex_dir_key[depth]#2); lock(&of->mutex); lock(&ovl_i_mutex_dir_key[depth]#2); rlock(sb_writers#5); *** DEADLOCK *** 2 locks held by syz.1.1351/13335: #0: ffff888027172428 (sb_writers#27){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557 #1: ffff888059674100 (&ovl_i_mutex_dir_key[depth] #2){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #2){++++}-{4:4}, at: open_last_lookups fs/namei.c:3804 [inline] #2){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4043 stack backtrace: CPU: 1 UID: 0 PID: 13335 Comm: syz.1.1351 Not tainted 6.15.0-next-20250606-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2046 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs.h:1793 [inline] sb_start_write+0x4d/0x1c0 include/linux/fs.h:1929 mnt_want_write+0x41/0x90 fs/namespace.c:557 ovl_create_object+0xfc/0x310 fs/overlayfs/dir.c:628 lookup_open fs/namei.c:3708 [inline] open_last_lookups fs/namei.c:3807 [inline] path_openat+0x14f1/0x3830 fs/namei.c:4043 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_creat fs/open.c:1530 [inline] __se_sys_creat fs/open.c:1524 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1524 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f14eef8e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f14ecdf6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007f14ef1b5fa0 RCX: 00007f14eef8e929 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00002000000002c0 RBP: 00007f14ef010b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f14ef1b5fa0 R15: 00007fff1db0f028 --- This report is generated by a bot. 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