linux-kernel - [syzbot] [bcachefs?] WARNING: locking bug in __timer_delete

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Message-ID: <674d2e48.050a0220.ad585.0042.GAE@google.com>
Date: Sun, 01 Dec 2024 19:49:28 -0800
From: syzbot <syzbot+b92c7b8dc15336fd1e19@...kaller.appspotmail.com>
To: kent.overstreet@...ux.dev, linux-bcachefs@...r.kernel.org, 
	linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [bcachefs?] WARNING: locking bug in __timer_delete_sync (2)

Hello,

syzbot found the following issue on:

HEAD commit:    7d4050728c83 Merge tag 'vfs-6.13-rc1.fixes' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12ed7530580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=36a116bcb42870bb
dashboard link: https://syzkaller.appspot.com/bug?extid=b92c7b8dc15336fd1e19
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/0402354de422/disk-7d405072.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/42baa2a574cb/vmlinux-7d405072.xz
kernel image: https://storage.googleapis.com/syzbot-assets/bcf1d8381ffb/bzImage-7d405072.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b92c7b8dc15336fd1e19@...kaller.appspotmail.com

------------[ cut here ]------------
Looking for class "sdp->delay_work)" with key init_srcu_struct_data.__key.29, but found a different class "(&sdp->delay_work)" with the same key
WARNING: CPU: 0 PID: 5841 at kernel/locking/lockdep.c:939 look_up_lock_class+0xdc/0x170 kernel/locking/lockdep.c:936
Modules linked in:
CPU: 0 UID: 0 PID: 5841 Comm: syz-executor Not tainted 6.12.0-syzkaller-10313-g7d4050728c83 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:look_up_lock_class+0xdc/0x170 kernel/locking/lockdep.c:936
Code: 01 0f 85 8a 00 00 00 c6 05 d3 21 3d 04 01 90 49 8b 16 49 8b 76 18 48 8b 8b b8 00 00 00 48 c7 c7 60 fa 0a 8c e8 e5 45 8c f5 90 <0f> 0b 90 90 eb 61 90 e8 78 83 ea f8 e8 83 a1 ab f5 48 c7 c7 a0 f9
RSP: 0018:ffffc90003da7790 EFLAGS: 00010046
RAX: 55568536ce262300 RBX: ffffffff93ce4d80 RCX: ffff88802f30bc00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003da78a0 R08: ffffffff81568b42 R09: 1ffff110170c519a
R10: dffffc0000000000 R11: ffffed10170c519b R12: ffffe8ffffc6a378
R13: ffffe8ffffc6a378 R14: ffffe8ffffc6a378 R15: ffffffff9a439560
FS:  000055556c511500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055de49281e48 CR3: 0000000033e94000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 register_lock_class+0x102/0x980 kernel/locking/lockdep.c:1290
 __lock_acquire+0xf3/0x2100 kernel/locking/lockdep.c:5101
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
 __timer_delete_sync+0x148/0x310 kernel/time/timer.c:1648
 del_timer_sync include/linux/timer.h:185 [inline]
 cleanup_srcu_struct+0x23e/0x4d0 kernel/rcu/srcutree.c:687
 bch2_fs_btree_iter_exit+0x3f0/0x480 fs/bcachefs/btree_iter.c:3446
 __bch2_fs_free fs/bcachefs/super.c:558 [inline]
 bch2_fs_release+0x216/0x7d0 fs/bcachefs/super.c:611
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x22f/0x480 lib/kobject.c:737
 deactivate_locked_super+0xc4/0x130 fs/super.c:473
 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373
 task_work_run+0x24f/0x310 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f94ef781b37
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe9cd38668 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f94ef781b37
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe9cd38720
RBP: 00007ffe9cd38720 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe9cd397a0
R13: 00007f94ef7f37dc R14: 000000000002cc80 R15: 00007ffe9cd397e0
 </TASK>


---
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