[syzbot] [bcachefs?] kernel BUG in __btree_trans_update_by_path

[syzbot <syzbot+8deb6ff4415db67a9f18@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    50c8770a42fa Add linux-next specific files for 20250702
git tree:       linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1191aebc580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d831c9dfe03f77ec
dashboard link: https://syzkaller.appspot.com/bug?extid=8deb6ff4415db67a9f18
compiler:       Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1311d3d4580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1770f982580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/eb40fda2e0ca/disk-50c8770a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cba4d214940c/vmlinux-50c8770a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4b23ed647866/bzImage-50c8770a.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/cd313604f9e1/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8deb6ff4415db67a9f18@syzkaller.appspotmail.com

  while marking u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq 1db8f60c84bb244c written 8 min_key POS_MIN durability: 1 ptr: 0:42:0 gen 0, fixing
 done
bcachefs (loop0): going read-write
bcachefs (loop0): journal_replay...
------------[ cut here ]------------
kernel BUG at fs/bcachefs/btree_update.c:339!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 5842 Comm: syz-executor286 Not tainted 6.16.0-rc4-next-20250702-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__btree_trans_update_by_path+0x1fd3/0x2010 fs/bcachefs/btree_update.c:339
Code: f6 ff ff 48 8b 7c 24 28 e8 ca dd f5 fd 48 ba 00 00 00 00 00 fc ff df e9 3d f6 ff ff e8 a6 c9 91 fd 90 0f 0b e8 9e c9 91 fd 90 <0f> 0b e8 96 c9 91 fd 90 0f 0b e8 8e c9 91 fd 90 0f 0b e8 86 c9 91
RSP: 0018:ffffc9000413ea18 EFLAGS: 00010293
RAX: ffffffff842e0b42 RBX: 0000000000008542 RCX: ffff88802ea71e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888031194010 R08: ffffffff84518baa R09: 0000000000000002
R10: 0000000000000003 R11: 0000000000000000 R12: ffff888074e00000
R13: ffff888031194000 R14: 0000000000000088 R15: 1ffff11006232802
FS:  000055555e045380(0000) GS:ffff888125c1d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e03c677168 CR3: 0000000078920000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 bch2_trans_update_by_path fs/bcachefs/btree_update.c:454 [inline]
 bch2_trans_update_ip+0x8f6/0x1f00 fs/bcachefs/btree_update.c:546
 bch2_trans_update fs/bcachefs/btree_update.h:123 [inline]
 bch2_journal_replay_key+0x4c1/0xb50 fs/bcachefs/recovery.c:311
 bch2_journal_replay+0x171d/0x2630 fs/bcachefs/recovery.c:396
 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:484 [inline]
 __bch2_run_recovery_passes+0x392/0x1010 fs/bcachefs/recovery_passes.c:539
 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:610
 bch2_fs_recovery+0x2690/0x3a50 fs/bcachefs/recovery.c:1005
 bch2_fs_start+0xaaf/0xda0 fs/bcachefs/super.c:1212
 bch2_fs_get_tree+0xb39/0x1540 fs/bcachefs/fs.c:2488
 vfs_get_tree+0x92/0x2b0 fs/super.c:1804
 do_new_mount+0x24a/0xa40 fs/namespace.c:3902
 do_mount fs/namespace.c:4239 [inline]
 __do_sys_mount fs/namespace.c:4450 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4427
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f878cb709ba
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc9f662588 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffc9f6625a0 RCX: 00007f878cb709ba
RDX: 00002000000000c0 RSI: 0000200000000080 RDI: 00007ffc9f6625a0
RBP: 0000200000000080 R08: 00007ffc9f6625e0 R09: 00000000000059b9
R10: 0000000000818001 R11: 0000000000000282 R12: 00002000000000c0
R13: 0000000000000004 R14: 0000000000000003 R15: 00007ffc9f6625e0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__btree_trans_update_by_path+0x1fd3/0x2010 fs/bcachefs/btree_update.c:339
Code: f6 ff ff 48 8b 7c 24 28 e8 ca dd f5 fd 48 ba 00 00 00 00 00 fc ff df e9 3d f6 ff ff e8 a6 c9 91 fd 90 0f 0b e8 9e c9 91 fd 90 <0f> 0b e8 96 c9 91 fd 90 0f 0b e8 8e c9 91 fd 90 0f 0b e8 86 c9 91
RSP: 0018:ffffc9000413ea18 EFLAGS: 00010293
RAX: ffffffff842e0b42 RBX: 0000000000008542 RCX: ffff88802ea71e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888031194010 R08: ffffffff84518baa R09: 0000000000000002
R10: 0000000000000003 R11: 0000000000000000 R12: ffff888074e00000
R13: ffff888031194000 R14: 0000000000000088 R15: 1ffff11006232802
FS:  000055555e045380(0000) GS:ffff888125d1d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8f8b3a1796 CR3: 0000000078920000 CR4: 00000000003526f0


---
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