[syzbot] [bcachefs?] kernel BUG in bch2_fs_free

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 0e1980c40b6e Add linux-next specific files for 20240531
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=12260914980000
kernel config: https://syzkaller.appspot.com/x/.config?x=d9c3ca4e54577b88
dashboard link: https://syzkaller.appspot.com/bug?extid=ab8e8a95fdeaf10f25fd
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/44fb1d8b5978/disk-0e1980c4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a66ce5caf0b2/vmlinux-0e1980c4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8992fc8fe046/bzImage-0e1980c4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ab8e8a...@syzkaller.appspotmail.com

bcachefs (loop3): bch2_check_allocations(): error fsck_errors_not_fixed
bcachefs (loop3): bch2_fs_recovery(): error fsck_errors_not_fixed
bcachefs (loop3): bch2_fs_start(): error starting filesystem fsck_errors_not_fixed
bcachefs (loop3): shutting down
------------[ cut here ]------------
kernel BUG at fs/bcachefs/super.c:647!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 PID: 6386 Comm: syz-executor.3 Not tainted 6.10.0-rc1-next-20240531-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:bch2_fs_free+0x3b1/0x3c0 fs/bcachefs/super.c:647
Code: e8 54 7b b8 fd e9 1a fe ff ff 89 d9 80 e1 07 38 c1 0f 8c 72 ff ff ff 48 89 df e8 3a 7b b8 fd e9 65 ff ff ff e8 40 8e 52 fd 90 <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90
RSP: 0000:ffffc90003ee7560 EFLAGS: 00010246
RAX: ffffffff8443edb0 RBX: ffff88805d7f0000 RCX: 0000000000040000
RDX: ffffc9000b05a000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: 0000000000000002 R08: ffffffff8443ec58 R09: 1ffff1100bafe008
R10: dffffc0000000000 R11: ffffed100bafe009 R12: ffff8880574003d0
R13: 0000000000000000 R14: ffff8880574007a6 R15: 1ffff1100ae800f4
FS: 00007faa8d2676c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f712de00400 CR3: 00000000113ea000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
bch2_fs_stop fs/bcachefs/super.c:661 [inline]
bch2_fs_open+0xb57/0xdf0 fs/bcachefs/super.c:2129
bch2_mount fs/bcachefs/fs.c:1908 [inline]
bch2_fs_get_tree+0x75e/0x14d0 fs/bcachefs/fs.c:2069
vfs_get_tree+0x90/0x2a0 fs/super.c:1780
do_new_mount+0x2be/0xb40 fs/namespace.c:3352
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faa8c47e5ea
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 09 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007faa8d266ef8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007faa8d266f80 RCX: 00007faa8c47e5ea
RDX: 0000000020002040 RSI: 0000000020002080 RDI: 00007faa8d266f40
RBP: 0000000020002040 R08: 00007faa8d266f80 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020002080
R13: 00007faa8d266f40 R14: 0000000000005b5d R15: 0000000020000140
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:bch2_fs_free+0x3b1/0x3c0 fs/bcachefs/super.c:647
Code: e8 54 7b b8 fd e9 1a fe ff ff 89 d9 80 e1 07 38 c1 0f 8c 72 ff ff ff 48 89 df e8 3a 7b b8 fd e9 65 ff ff ff e8 40 8e 52 fd 90 <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90
RSP: 0000:ffffc90003ee7560 EFLAGS: 00010246
RAX: ffffffff8443edb0 RBX: ffff88805d7f0000 RCX: 0000000000040000
RDX: ffffc9000b05a000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: 0000000000000002 R08: ffffffff8443ec58 R09: 1ffff1100bafe008
R10: dffffc0000000000 R11: ffffed100bafe009 R12: ffff8880574003d0
R13: 0000000000000000 R14: ffff8880574007a6 R15: 1ffff1100ae800f4
FS: 00007faa8d2676c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000140 CR3: 00000000113ea000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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