syzbot

bcachefs (loop0): running explicit recovery pass scan_for_btree_nodes (1), currently at recovery_pass_empty (0)
bcachefs (loop0): error reading btree root btree=(unknown btree 31) level=0: btree_node_read_error, fixing
bcachefs (loop0): scan_for_btree_nodes...
bcachefs (loop0): btree node scan found 7 nodes after overwrites
 done
bcachefs (loop0): check_topology...
Oops: general protection fault, probably for non-canonical address 0xdffffc000000000e: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000070-0x0000000000000077]
CPU: 0 UID: 0 PID: 5829 Comm: syz-executor700 Not tainted 6.15.0-rc1-syzkaller-00288-ge618ee89561b #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:kasan_byte_accessible+0x12/0x20 mm/kasan/generic.c:199
Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 c3 cc cc cc cc 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000417f010 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000070 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8489792e RDI: 000000000000000e
RBP: ffffffff93657020 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1006781d43 R12: 0000000000000001
R13: 0000000000000001 R14: ffffffff8489792e R15: 0000000000000070
FS:  0000555559833380(0000) GS:ffff888124fc9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc64bdb988 CR3: 0000000075e52000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __kasan_check_byte+0x14/0x40 mm/kasan/common.c:556
 kasan_check_byte include/linux/kasan.h:399 [inline]
 lock_acquire+0x89/0x2f0 kernel/locking/lockdep.c:5840
 six_lock_ip_waiter+0x9e/0x160 fs/bcachefs/six.c:553
 __btree_node_lock_nopath fs/bcachefs/btree_locking.h:229 [inline]
 btree_node_lock_nopath_nofail fs/bcachefs/btree_locking.h:252 [inline]
 bch2_check_topology+0x8b7/0xe40 fs/bcachefs/btree_gc.c:553
 bch2_run_recovery_pass+0xf0/0x1e0 fs/bcachefs/recovery_passes.c:226
 bch2_run_recovery_passes+0x2ad/0xa90 fs/bcachefs/recovery_passes.c:285
 bch2_fs_recovery+0x292a/0x3e20 fs/bcachefs/recovery.c:936
 bch2_fs_start+0x310/0x620 fs/bcachefs/super.c:1059
 bch2_fs_get_tree+0x113e/0x18f0 fs/bcachefs/fs.c:2253
 vfs_get_tree+0x90/0x2b0 fs/super.c:1759
 do_new_mount+0x2cf/0xb70 fs/namespace.c:3879
 do_mount fs/namespace.c:4219 [inline]
 __do_sys_mount fs/namespace.c:4430 [inline]
 __se_sys_mount+0x38c/0x400 fs/namespace.c:4407
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc1937ece2a
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:00007ffd66814868 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffd66814880 RCX: 00007fc1937ece2a
RDX: 00002000000000c0 RSI: 0000200000000040 RDI: 00007ffd66814880
RBP: 0000200000000040 R08: 00007ffd668148c0 R09: 0000000000005952
R10: 0000000000000000 R11: 0000000000000282 R12: 00002000000000c0
R13: 00007ffd668148c0 R14: 0000000000000003 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:kasan_byte_accessible+0x12/0x20 mm/kasan/generic.c:199
Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 c3 cc cc cc cc 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000417f010 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000070 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8489792e RDI: 000000000000000e
RBP: ffffffff93657020 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1006781d43 R12: 0000000000000001
R13: 0000000000000001 R14: ffffffff8489792e R15: 0000000000000070
FS:  0000555559833380(0000) GS:ffff888124fc9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc64bdb988 CR3: 0000000075e52000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
   7:	00
   8:	90                   	nop
   9:	90                   	nop
   a:	90                   	nop
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	66 0f 1f 00          	nopw   (%rax)
  1c:	48 c1 ef 03          	shr    $0x3,%rdi
  20:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  27:	fc ff df
* 2a:	0f b6 04 07          	movzbl (%rdi,%rax,1),%eax <-- trapping instruction
  2e:	3c 08                	cmp    $0x8,%al
  30:	0f 92 c0             	setb   %al
  33:	c3                   	ret
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	cc                   	int3
  38:	90                   	nop
  39:	90                   	nop
  3a:	90                   	nop
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop