linux-kernel - [syzbot] [bcachefs?] kernel BUG in bch2_fs_btree_cache

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Message-ID: <678d76b3.050a0220.303755.0060.GAE@google.com>
Date: Sun, 19 Jan 2025 14:03:31 -0800
From: syzbot <syzbot+cb21e918562a9fa8ba88@...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?] kernel BUG in bch2_fs_btree_cache_exit (2)

Hello,

syzbot found the following issue on:

HEAD commit:    619f0b6fad52 Merge tag 'seccomp-v6.13-rc8' of git://git.ke..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1484fcb0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c676c8e1379fdfaa
dashboard link: https://syzkaller.appspot.com/bug?extid=cb21e918562a9fa8ba88
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/a9c9c3056af4/disk-619f0b6f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/558f94c52108/vmlinux-619f0b6f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/595b7ae81ee0/bzImage-619f0b6f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cb21e918562a9fa8ba88@...kaller.appspotmail.com

bcachefs (loop0): shutdown complete
------------[ cut here ]------------
kernel BUG at fs/bcachefs/btree_cache.c:608!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 9344 Comm: syz-executor Not tainted 6.13.0-rc7-syzkaller-00043-g619f0b6fad52 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:bch2_fs_btree_cache_exit+0x1449/0x1530 fs/bcachefs/btree_cache.c:607
Code: fd 90 0f 0b e8 c8 53 89 fd 90 0f 0b e8 c0 53 89 fd 90 0f 0b e8 b8 53 89 fd 90 0f 0b e8 b0 53 89 fd 90 0f 0b e8 a8 53 89 fd 90 <0f> 0b e8 a0 53 89 fd 90 0f 0b e8 98 53 89 fd 90 0f 0b e8 90 53 89
RSP: 0000:ffffc90002f07c38 EFLAGS: 00010293
RAX: ffffffff84161e78 RBX: 0000000000001000 RCX: ffff88802e72da00
RDX: 0000000000000000 RSI: 0000000000001000 RDI: 0000000000000000
RBP: ffff888029cec8b0 R08: ffffffff841613ec R09: 1ffff1100539d916
R10: dffffc0000000000 R11: ffffed100539d917 R12: ffff888029ceca28
R13: ffff88803009ba28 R14: 1ffff1100539d916 R15: 1ffff1100539d945
FS:  000055557c781500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f53d8c51000 CR3: 000000004c752000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __bch2_fs_free fs/bcachefs/super.c:557 [inline]
 bch2_fs_release+0x20e/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: 0033:0x7fca2c387057
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:00007fffeac39e78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fca2c387057
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffeac39f30
RBP: 00007fffeac39f30 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffeac3afb0
R13: 00007fca2c4018f4 R14: 00007fffeac3aff0 R15: 0000000000000001
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---


---
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