Oops: general protection fault, probably for non-canonical address 0xdffffc0000000013: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000098-0x000000000000009f]
CPU: 0 UID: 0 PID: 1141 Comm: kworker/u8:6 Not tainted 6.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: writeback wb_workfn (flush-bcachefs-25)
RIP: 0010:btree_path_lock_root fs/bcachefs/btree_iter.c:732 [inline]
RIP: 0010:bch2_btree_path_traverse_one+0x94a/0x2940 fs/bcachefs/btree_iter.c:1183
Code: 89 44 24 60 42 80 3c 20 00 74 08 4c 89 ef e8 2d 40 e8 fd 49 8b 45 00 48 89 44 24 48 48 8d 90 98 00 00 00 48 89 d0 48 c1 e8 03 <42> 0f b6 04 20 84 c0 48 89 94 24 80 00 00 00 0f 85 ee 10 00 00 4c
RSP: 0018:ffffc900040b5060 EFLAGS: 00010202
RAX: 0000000000000013 RBX: 0000000000000000 RCX: ffff8880278a3c00
RDX: 0000000000000098 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900040b5350 R08: ffffffff841b0610 R09: ffffffff841ae689
R10: 0000000000000002 R11: ffff8880278a3c00 R12: dffffc0000000000
R13: ffff888070c014d8 R14: ffff88801e78c2f8 R15: 000000000000110b
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555679165c8 CR3: 00000000667e6000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:247 [inline]
 __bch2_btree_iter_peek fs/bcachefs/btree_iter.c:2210 [inline]
 bch2_btree_iter_peek_upto+0xb58/0x70e0 fs/bcachefs/btree_iter.c:2310
 bch2_btree_iter_peek_upto_type fs/bcachefs/btree_iter.h:685 [inline]
 bch2_bucket_alloc_freelist fs/bcachefs/alloc_foreground.c:495 [inline]
 bch2_bucket_alloc_trans+0x1122/0x3a50 fs/bcachefs/alloc_foreground.c:648
 bch2_bucket_alloc_set_trans+0x517/0xd30 fs/bcachefs/alloc_foreground.c:808
 __open_bucket_add_buckets+0x13d0/0x1ec0 fs/bcachefs/alloc_foreground.c:1057
 open_bucket_add_buckets+0x33a/0x410 fs/bcachefs/alloc_foreground.c:1101
 bch2_alloc_sectors_start_trans+0xc55/0x2030 fs/bcachefs/alloc_foreground.c:1424
 __bch2_write+0x72b/0x5dd0 fs/bcachefs/io_write.c:1437
 bch2_write+0x9b5/0x1760 fs/bcachefs/io_write.c:1631
 closure_queue include/linux/closure.h:270 [inline]
 closure_call include/linux/closure.h:432 [inline]
 bch2_writepage_do_io fs/bcachefs/fs-io-buffered.c:449 [inline]
 bch2_writepages+0x284/0x390 fs/bcachefs/fs-io-buffered.c:641
 do_writepages+0x35f/0x880 mm/page-writeback.c:2708
 __writeback_single_inode+0x14f/0x10d0 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976
 wb_writeback+0x413/0xb80 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x410/0x1080 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317
 worker_thread+0x870/0xd30 kernel/workqueue.c:3398
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:btree_path_lock_root fs/bcachefs/btree_iter.c:732 [inline]
RIP: 0010:bch2_btree_path_traverse_one+0x94a/0x2940 fs/bcachefs/btree_iter.c:1183
Code: 89 44 24 60 42 80 3c 20 00 74 08 4c 89 ef e8 2d 40 e8 fd 49 8b 45 00 48 89 44 24 48 48 8d 90 98 00 00 00 48 89 d0 48 c1 e8 03 <42> 0f b6 04 20 84 c0 48 89 94 24 80 00 00 00 0f 85 ee 10 00 00 4c
RSP: 0018:ffffc900040b5060 EFLAGS: 00010202
RAX: 0000000000000013 RBX: 0000000000000000 RCX: ffff8880278a3c00
RDX: 0000000000000098 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900040b5350 R08: ffffffff841b0610 R09: ffffffff841ae689
R10: 0000000000000002 R11: ffff8880278a3c00 R12: dffffc0000000000
R13: ffff888070c014d8 R14: ffff88801e78c2f8 R15: 000000000000110b
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056215f225950 CR3: 00000000313ec000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	89 44 24 60          	mov    %eax,0x60(%rsp)
   4:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1)
   9:	74 08                	je     0x13
   b:	4c 89 ef             	mov    %r13,%rdi
   e:	e8 2d 40 e8 fd       	call   0xfde84040
  13:	49 8b 45 00          	mov    0x0(%r13),%rax
  17:	48 89 44 24 48       	mov    %rax,0x48(%rsp)
  1c:	48 8d 90 98 00 00 00 	lea    0x98(%rax),%rdx
  23:	48 89 d0             	mov    %rdx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	48 89 94 24 80 00 00 	mov    %rdx,0x80(%rsp)
  38:	00
  39:	0f 85 ee 10 00 00    	jne    0x112d
  3f:	4c                   	rex.WR