[syzbot] [bcachefs?] kernel BUG in bch2_fs_release (2)

syzbot
2024-06-28T03:49:20Z

Hello,

syzbot found the following issue on:

HEAD commit: f2661062f16b Linux 6.10-rc5
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=159df741980000
kernel config: https://syzkaller.appspot.com/x/.config?x=53ab35b556129242
dashboard link: https://syzkaller.appspot.com/bug?extid=9db8552458d57264a358
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-f2661062.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c8274ddce14a/vmlinux-f2661062.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e3623ed3bb77/bzImage-f2661062.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9db8552458d57264a358@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at fs/bcachefs/super.c:567!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 PID: 5232 Comm: syz-executor.1 Not tainted 6.10.0-rc5-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__bch2_fs_free fs/bcachefs/super.c:567 [inline]
RIP: 0010:bch2_fs_release+0x722/0x870 fs/bcachefs/super.c:605
Code: 89 ee e8 c1 85 79 fd 4d 85 ed 75 20 e8 87 8a 79 fd 31 ff 4c 89 f6 e8 ad 85 79 fd 4d 85 f6 0f 84 4f fb ff ff e8 6f 8a 79 fd 90 <0f> 0b e8 67 8a 79 fd bf 07 00 00 00 f3 49 0f bc c5 89 c6 41 89 c5
RSP: 0018:ffffc90002f47d38 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888060900068 RCX: ffffffff84150573
RDX: ffff888020248000 RSI: ffffffff84150581 RDI: 0000000000000007
RBP: ffff888060900000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000607f8106a5d8
R13: 0000000000000008 R14: 0000000000000001 R15: 0000000000000008
FS: 0000000000000000(0000) GS:ffff88802c000000(0063) knlGS:0000000057322400
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000032434000 CR3: 0000000047630000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x1fa/0x5b0 lib/kobject.c:737
deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
deactivate_super+0xde/0x100 fs/super.c:506
cleanup_mnt+0x222/0x450 fs/namespace.c:1267
task_work_run+0x14e/0x250 kernel/task_work.c:180
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:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
__do_fast_syscall_32+0x80/0x120 arch/x86/entry/common.c:389
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf72c2579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000ff88f5f8 EFLAGS: 00000292 ORIG_RAX: 0000000000000034
RAX: 0000000000000000 RBX: 00000000ff88f6a0 RCX: 0000000000000009
RDX: 00000000f7418ff4 RSI: 00000000f7369361 RDI: 00000000ff890744
RBP: 00000000ff88f6a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__bch2_fs_free fs/bcachefs/super.c:567 [inline]
RIP: 0010:bch2_fs_release+0x722/0x870 fs/bcachefs/super.c:605
Code: 89 ee e8 c1 85 79 fd 4d 85 ed 75 20 e8 87 8a 79 fd 31 ff 4c 89 f6 e8 ad 85 79 fd 4d 85 f6 0f 84 4f fb ff ff e8 6f 8a 79 fd 90 <0f> 0b e8 67 8a 79 fd bf 07 00 00 00 f3 49 0f bc c5 89 c6 41 89 c5
RSP: 0018:ffffc90002f47d38 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888060900068 RCX: ffffffff84150573
RDX: ffff888020248000 RSI: ffffffff84150581 RDI: 0000000000000007
RBP: ffff888060900000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000607f8106a5d8
R13: 0000000000000008 R14: 0000000000000001 R15: 0000000000000008
FS: 0000000000000000(0000) GS:ffff88802c000000(0063) knlGS:0000000057322400
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000032434000 CR3: 0000000047630000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 2 bytes skipped:
0: 10 06 adc %al,(%rsi)
2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi
6: 10 07 adc %al,(%rdi)
8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi
c: 10 08 adc %cl,(%rax)
e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi
1e: 00 51 52 add %dl,0x52(%rcx)
21: 55 push %rbp
22: 89 e5 mov %esp,%ebp
24: 0f 34 sysenter
26: cd 80 int $0x80
* 28: 5d pop %rbp <-- trapping instruction
29: 5a pop %rdx
2a: 59 pop %rcx
2b: c3 ret
2c: 90 nop
2d: 90 nop
2e: 90 nop
2f: 90 nop
30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi

---
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