[syzbot] [bcachefs?] kernel BUG in bch2_fs_release

From: syzbot
Date: Fri May 24 2024 - 23:50:29 EST

Hello,

syzbot found the following issue on:

HEAD commit: 6e51b4b5bbc0 Merge tag 'mips_6.10' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1499dbe4980000
kernel config: https://syzkaller.appspot.com/x/.config?x=5d5d254b2919253a
dashboard link: https://syzkaller.appspot.com/bug?extid=a8074a75b8d73328751e
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-6e51b4b5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4a78abf5bef3/vmlinux-6e51b4b5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/283fe971fc00/bzImage-6e51b4b5.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a8074a75b8d73328751e@xxxxxxxxxxxxxxxxxxxxxxxxx

loop0: detected capacity change from 0 to 32768
workqueue: Failed to create a rescuer kthread for wq "bcachefs": -EINTR
bcachefs (076a1832-646e-4f3c-b13d-b3e266154efd): shutdown complete
------------[ cut here ]------------
kernel BUG at fs/bcachefs/super.c:567!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 2 PID: 6873 Comm: syz-executor.0 Not tainted 6.9.0-syzkaller-09868-g6e51b4b5bbc0 #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+0x6b0/0x810 fs/bcachefs/super.c:603
Code: 89 ee e8 63 7d 7b fd 48 85 ed 75 34 e8 29 82 7b fd 31 ff 4c 89 ee e8 4f 7d 7b fd 4d 85 ed 0f 84 02 fc ff ff e8 11 82 7b fd 90 <0f> 0b e8 09 82 7b fd 48 8b 7c 24 10 e8 7f 63 d9 ff e9 cb fa ff ff
RSP: 0000:ffffc9000e047410 EFLAGS: 00010246
RAX: 0000000000040000 RBX: ffff888061080068 RCX: ffffc90003f21000
RDX: 0000000000040000 RSI: ffffffff8412febf RDI: 0000000000000007
RBP: 0000000000000008 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000008
R13: 0000000000000001 R14: dffffc0000000000 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88802c200000(0063) knlGS:00000000f5e8fb40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000edabe000 CR3: 00000000120f0000 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
bch2_fs_alloc+0xe49/0x2550 fs/bcachefs/super.c:954
bch2_fs_open+0x713/0x10f0 fs/bcachefs/super.c:2102
bch2_mount+0xd41/0x1090 fs/bcachefs/fs.c:1917
legacy_get_tree+0x109/0x220 fs/fs_context.c:662
vfs_get_tree+0x8f/0x380 fs/super.c:1779
do_new_mount fs/namespace.c:3352 [inline]
path_mount+0x6e1/0x1f10 fs/namespace.c:3679
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount fs/namespace.c:3875 [inline]
__ia32_sys_mount+0x295/0x320 fs/namespace.c:3875
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf729d579
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:00000000f5e8f400 EFLAGS: 00000292 ORIG_RAX: 0000000000000015
RAX: ffffffffffffffda RBX: 00000000f5e8f460 RCX: 0000000020000080
RDX: 0000000020011a00 RSI: 0000000001200014 RDI: 00000000f5e8f4a0
RBP: 00000000f5e8f460 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 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+0x6b0/0x810 fs/bcachefs/super.c:603
Code: 89 ee e8 63 7d 7b fd 48 85 ed 75 34 e8 29 82 7b fd 31 ff 4c 89 ee e8 4f 7d 7b fd 4d 85 ed 0f 84 02 fc ff ff e8 11 82 7b fd 90 <0f> 0b e8 09 82 7b fd 48 8b 7c 24 10 e8 7f 63 d9 ff e9 cb fa ff ff
RSP: 0000:ffffc9000e047410 EFLAGS: 00010246
RAX: 0000000000040000 RBX: ffff888061080068 RCX: ffffc90003f21000
RDX: 0000000000040000 RSI: ffffffff8412febf RDI: 0000000000000007
RBP: 0000000000000008 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000008
R13: 0000000000000001 R14: dffffc0000000000 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88802c200000(0063) knlGS:00000000f5e8fb40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000edabe000 CR3: 00000000120f0000 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


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