[syzbot] [bcachefs?] kernel BUG in bch2_btree_node_iter_init

[syzbot <syzbot+7b8a2c442d5a4859b680@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    69e858e0b8b2 Merge tag 'uml-for-linus-6.14-rc1' of git://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1148c518580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d033b14aeef39158
dashboard link: https://syzkaller.appspot.com/bug?extid=7b8a2c442d5a4859b680
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=150715f8580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=102e8b24580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-69e858e0.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a53b888c1f3f/vmlinux-69e858e0.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6b5e17edafc0/bzImage-69e858e0.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/6d9bc71b6ead/mount_5.gz

The issue was bisected to:

commit 14152654805256d760315ec24e414363bfa19a06
Author: Kent Overstreet <kent.overstreet@linux.dev>
Date:   Mon Nov 25 05:21:27 2024 +0000

    bcachefs: Bad btree roots are now autofix

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=16492d18580000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=15492d18580000
console output: https://syzkaller.appspot.com/x/log.txt?x=11492d18580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7b8a2c442d5a4859b680@syzkaller.appspotmail.com
Fixes: 141526548052 ("bcachefs: Bad btree roots are now autofix")

bcachefs (loop0): alloc_read... done
bcachefs (loop0): stripes_read... done
bcachefs (loop0): snapshots_read... done
bcachefs (loop0): check_allocations...
------------[ cut here ]------------
kernel BUG at fs/bcachefs/bset.c:1308!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5524 Comm: syz-executor285 Not tainted 6.13.0-syzkaller-09760-g69e858e0b8b2 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:bch2_btree_node_iter_init+0x4272/0x4280 fs/bcachefs/bset.c:1308
Code: fd 90 0f 0b e8 bf 9e 84 fd 90 0f 0b e8 b7 9e 84 fd 90 0f 0b e8 af 9e 84 fd 90 0f 0b e8 a7 9e 84 fd 90 0f 0b e8 9f 9e 84 fd 90 <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90
RSP: 0000:ffffc9000d7b5de0 EFLAGS: 00010293
RAX: ffffffff843ace21 RBX: 0000000000000001 RCX: ffff88803ebb8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000d7b6050 R08: ffffffff843a8fc6 R09: 0000000000000000
R10: ffffc9000d7b5f70 R11: fffff52001af6bf1 R12: ffff888056900040
R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007f13e240b6c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f13dadff000 CR3: 00000000441be000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __btree_path_level_init fs/bcachefs/btree_iter.c:617 [inline]
 bch2_btree_path_level_init+0x4d2/0x9f0 fs/bcachefs/btree_iter.c:637
 btree_path_lock_root fs/bcachefs/btree_iter.c:787 [inline]
 bch2_btree_path_traverse_one+0x108b/0x2930 fs/bcachefs/btree_iter.c:1203
 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:249 [inline]
 __bch2_btree_iter_peek fs/bcachefs/btree_iter.c:2270 [inline]
 bch2_btree_iter_peek_max+0xc06/0x6320 fs/bcachefs/btree_iter.c:2367
 bch2_btree_iter_peek_max_type fs/bcachefs/btree_iter.h:681 [inline]
 bch2_gc_reflink_start+0x461/0xa50 fs/bcachefs/reflink.c:828
 bch2_check_allocations+0x680/0x6aa0 fs/bcachefs/btree_gc.c:1027
 bch2_run_recovery_pass+0xf0/0x1e0 fs/bcachefs/recovery_passes.c:226
 bch2_run_recovery_passes+0x2ad/0xa90 fs/bcachefs/recovery_passes.c:291
 bch2_fs_recovery+0x265a/0x3de0 fs/bcachefs/recovery.c:937
 bch2_fs_start+0x37c/0x610 fs/bcachefs/super.c:1030
 bch2_fs_get_tree+0xd8d/0x1740 fs/bcachefs/fs.c:2203
 vfs_get_tree+0x90/0x2b0 fs/super.c:1814
 do_new_mount+0x2be/0xb40 fs/namespace.c:3560
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
 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: 0033:0x7f13e2460cba
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 4e 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:00007f13e240afa8 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f13e240afc0 RCX: 00007f13e2460cba
RDX: 0000000020000000 RSI: 0000000020000040 RDI: 00007f13e240afc0
RBP: 0000000000000006 R08: 00007f13e240b000 R09: 0000000000005939
R10: 0000000000000000 R11: 0000000000000282 R12: 00007f13e240b000
R13: 0000000000000000 R14: 0000000000000004 R15: 0000000001000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:bch2_btree_node_iter_init+0x4272/0x4280 fs/bcachefs/bset.c:1308
Code: fd 90 0f 0b e8 bf 9e 84 fd 90 0f 0b e8 b7 9e 84 fd 90 0f 0b e8 af 9e 84 fd 90 0f 0b e8 a7 9e 84 fd 90 0f 0b e8 9f 9e 84 fd 90 <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90
RSP: 0000:ffffc9000d7b5de0 EFLAGS: 00010293
RAX: ffffffff843ace21 RBX: 0000000000000001 RCX: ffff88803ebb8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000d7b6050 R08: ffffffff843a8fc6 R09: 0000000000000000
R10: ffffc9000d7b5f70 R11: fffff52001af6bf1 R12: ffff888056900040
R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007f13e240b6c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f13dadff000 CR3: 00000000441be000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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