  ret btree_node_read_err_bad_node
bcachefs (loop2): error reading btree root btree=(unknown btree 31) level=0: btree_node_read_error, fixing
bcachefs (loop2): 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: 5916 Comm: syz.2.5 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__do_six_trylock+0x11a/0x7b0
Code: 4c 8b 74 24 18 4c 89 f7 be 04 00 00 00 e8 5e 7e cd 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 97 7b cd fd 49 83 3c 24 00 0f 84
RSP: 0018:ffffc9000314ee80 EFLAGS: 00010206
RAX: 0000000000000002 RBX: 0000000000000000 RCX: 0000000000000005
RDX: ffffffff84559819 RSI: ffffffff8e7a5260 RDI: 0000000000000000
RBP: ffffc9000314ef48 R08: ffff888020ab8000 R09: 0000000000000002
R10: 0000000000000002 R11: 0000000000000002 R12: 0000000000000018
R13: 1ffff92000629dd8 R14: 0000000000000003 R15: dffffc0000000000
FS:  00007f46ed7736c0(0000) GS:ffff8881a3c1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f9a4686b88 CR3: 00000000299fe000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 six_lock_ip_waiter+0xbf/0x170
 bch2_check_topology+0x61a/0xe00
 __bch2_run_recovery_passes+0x3bd/0x1060
 bch2_run_recovery_passes+0x184/0x210
 bch2_fs_recovery+0x2690/0x3a50
 bch2_fs_start+0xaaf/0xda0
 bch2_fs_get_tree+0xb39/0x1520
 vfs_get_tree+0x92/0x2b0
 do_new_mount+0x2a2/0x9e0
 __se_sys_mount+0x317/0x410
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f46ec99038a
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:00007f46ed772e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f46ed772ef0 RCX: 00007f46ec99038a
RDX: 0000200000000000 RSI: 0000200000005900 RDI: 00007f46ed772eb0
RBP: 0000200000000000 R08: 00007f46ed772ef0 R09: 0000000000010000
R10: 0000000000010000 R11: 0000000000000246 R12: 0000200000005900
R13: 00007f46ed772eb0 R14: 0000000000005958 R15: 0000200000000040
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__do_six_trylock+0x11a/0x7b0
Code: 4c 8b 74 24 18 4c 89 f7 be 04 00 00 00 e8 5e 7e cd 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 97 7b cd fd 49 83 3c 24 00 0f 84
RSP: 0018:ffffc9000314ee80 EFLAGS: 00010206
RAX: 0000000000000002 RBX: 0000000000000000 RCX: 0000000000000005
RDX: ffffffff84559819 RSI: ffffffff8e7a5260 RDI: 0000000000000000
RBP: ffffc9000314ef48 R08: ffff888020ab8000 R09: 0000000000000002
R10: 0000000000000002 R11: 0000000000000002 R12: 0000000000000018
R13: 1ffff92000629dd8 R14: 0000000000000003 R15: dffffc0000000000
FS:  00007f46ed7736c0(0000) GS:ffff8881a3c1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9195bf8580 CR3: 00000000299fe000 CR4: 00000000000006f0
