running recovery pass check_topology (2), currently at recovery_pass_empty (0)
  running recovery pass scan_for_btree_nodes (1), currently at recovery_pass_empty (0)
  ret btree_node_read_err_bad_node
bcachefs (loop0): error reading btree root btree=(unknown btree 36) level=0: btree_node_read_error, fixing
bcachefs (loop0): check_topology...
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 1 UID: 0 PID: 6522 Comm: syz.0.17 Tainted: G        W           syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__do_six_trylock+0x11a/0x7b0 fs/bcachefs/six.c:154
Code: 4c 8b 74 24 18 4c 89 f7 be 04 00 00 00 e8 ae 22 d2 fd f0 41 81 06 00 00 00 08 e9 37 03 00 00 4c 8d 63 18 4d 89 e6 49 c1 ee 03 <43> 80 3c 3e 00 74 08 4c 89 e7 e8 e7 1f d2 fd 49 83 3c 24 00 0f 84
RSP: 0018:ffffc9000410ee80 EFLAGS: 00010206
RAX: 0000000000000002 RBX: 0000000000000000 RCX: 0000000000000005
RDX: ffffffff844b6ee9 RSI: ffffffff8e00abc0 RDI: 0000000000000000
RBP: ffffc9000410ef48 R08: ffff8880251d1dc0 R09: 0000000000000002
R10: 0000000000000100 R11: 0000000000000002 R12: 0000000000000018
R13: 1ffff92000821dd8 R14: 0000000000000003 R15: dffffc0000000000
FS:  00007fd6910fe6c0(0000) GS:ffff8881269c4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbf70ea5000 CR3: 000000004a840000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 do_six_trylock fs/bcachefs/six.c:282 [inline]
 six_lock_ip_waiter+0xbf/0x170 fs/bcachefs/six.c:552
 __btree_node_lock_nopath fs/bcachefs/btree_locking.h:237 [inline]
 btree_node_lock_nopath_nofail fs/bcachefs/btree_locking.h:260 [inline]
 bch2_check_topology+0x61a/0xe00 fs/bcachefs/btree_gc.c:601
 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:484 [inline]
 __bch2_run_recovery_passes+0x3bd/0x1060 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:1016
 bch2_fs_start+0xaaf/0xda0 fs/bcachefs/super.c:1213
 bch2_fs_get_tree+0xb39/0x1520 fs/bcachefs/fs.c:2488
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4324
 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: 0033:0x7fd691e9030a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd6910fde68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fd6910fdef0 RCX: 00007fd691e9030a
RDX: 00002000000000c0 RSI: 0000200000000180 RDI: 00007fd6910fdeb0
RBP: 00002000000000c0 R08: 00007fd6910fdef0 R09: 0000000001808044
R10: 0000000001808044 R11: 0000000000000246 R12: 0000200000000180
R13: 00007fd6910fdeb0 R14: 0000000000005945 R15: 0000200000000200
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__do_six_trylock+0x11a/0x7b0 fs/bcachefs/six.c:154
Code: 4c 8b 74 24 18 4c 89 f7 be 04 00 00 00 e8 ae 22 d2 fd f0 41 81 06 00 00 00 08 e9 37 03 00 00 4c 8d 63 18 4d 89 e6 49 c1 ee 03 <43> 80 3c 3e 00 74 08 4c 89 e7 e8 e7 1f d2 fd 49 83 3c 24 00 0f 84
RSP: 0018:ffffc9000410ee80 EFLAGS: 00010206
RAX: 0000000000000002 RBX: 0000000000000000 RCX: 0000000000000005
RDX: ffffffff844b6ee9 RSI: ffffffff8e00abc0 RDI: 0000000000000000
RBP: ffffc9000410ef48 R08: ffff8880251d1dc0 R09: 0000000000000002
R10: 0000000000000100 R11: 0000000000000002 R12: 0000000000000018
R13: 1ffff92000821dd8 R14: 0000000000000003 R15: dffffc0000000000
FS:  00007fd6910fe6c0(0000) GS:ffff8881269c4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbf70ea5000 CR3: 000000004a840000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	4c 8b 74 24 18       	mov    0x18(%rsp),%r14
   5:	4c 89 f7             	mov    %r14,%rdi
   8:	be 04 00 00 00       	mov    $0x4,%esi
   d:	e8 ae 22 d2 fd       	call   0xfdd222c0
  12:	f0 41 81 06 00 00 00 	lock addl $0x8000000,(%r14)
  19:	08
  1a:	e9 37 03 00 00       	jmp    0x356
  1f:	4c 8d 63 18          	lea    0x18(%rbx),%r12
  23:	4d 89 e6             	mov    %r12,%r14
  26:	49 c1 ee 03          	shr    $0x3,%r14
* 2a:	43 80 3c 3e 00       	cmpb   $0x0,(%r14,%r15,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 e7             	mov    %r12,%rdi
  34:	e8 e7 1f d2 fd       	call   0xfdd22020
  39:	49 83 3c 24 00       	cmpq   $0x0,(%r12)
  3e:	0f                   	.byte 0xf
  3f:	84                   	.byte 0x84