syzbot

loop0: detected capacity change from 0 to 2048
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 PID: 3613 Comm: syz-executor141 Not tainted 6.0.0-syzkaller-09423-g493ffd6605b2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
RIP: 0010:nilfs_bmap_lookup_at_level+0xb9/0x350 fs/nilfs2/bmap.c:69
Code: 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 8b b3 93 fe 4c 8b 33 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 69 b3 93 fe 4c 89 ff 4c 89 ee 44 89
RSP: 0018:ffffc90003d7f440 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888071912760 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff8880719126c8
RBP: ffffc90003d7f4f0 R08: dffffc0000000000 R09: ffffed100e3224da
R10: ffffed100e3224da R11: 1ffff1100e3224d9 R12: 0000000000000001
R13: 0000000000000002 R14: 0000000000000000 R15: ffff888071912688
FS:  000055555669a300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556ae87cf288 CR3: 000000001ca64000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 nilfs_bmap_lookup fs/nilfs2/bmap.h:170 [inline]
 nilfs_mdt_submit_block+0x23d/0x520 fs/nilfs2/mdt.c:142
 nilfs_mdt_read_block+0xa3/0x460 fs/nilfs2/mdt.c:176
 nilfs_mdt_get_block+0x104/0x820 fs/nilfs2/mdt.c:251
 nilfs_palloc_get_block+0x142/0x240 fs/nilfs2/alloc.c:216
 nilfs_palloc_get_entry_block+0x1e8/0x2e0 fs/nilfs2/alloc.c:318
 nilfs_ifile_get_inode_block+0xf0/0x1a0 fs/nilfs2/ifile.c:143
 __nilfs_read_inode fs/nilfs2/inode.c:477 [inline]
 nilfs_iget+0x253/0x8b0 fs/nilfs2/inode.c:603
 nilfs_get_root_dentry+0x28/0x230 fs/nilfs2/super.c:904
 nilfs_fill_super+0x3dd/0x5d0 fs/nilfs2/super.c:1078
 nilfs_mount+0x613/0x9b0 fs/nilfs2/super.c:1317
 legacy_get_tree+0xea/0x180 fs/fs_context.c:610
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x289/0xad0 fs/namespace.c:3040
 do_mount fs/namespace.c:3383 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3568
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7feeffab361a
Code: 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcc7ff83f8 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007feeffab361a
RDX: 00000000200000c0 RSI: 0000000020000100 RDI: 00007ffcc7ff8410
RBP: 00007ffcc7ff8410 R08: 00007ffcc7ff8450 R09: 000055555669a2c0
R10: 0000000000000000 R11: 0000000000000286 R12: 0000000000000004
R13: 00007ffcc7ff8450 R14: 000000000000003a R15: 0000000020000770
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:nilfs_bmap_lookup_at_level+0xb9/0x350 fs/nilfs2/bmap.c:69
Code: 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 8b b3 93 fe 4c 8b 33 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 69 b3 93 fe 4c 89 ff 4c 89 ee 44 89
RSP: 0018:ffffc90003d7f440 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888071912760 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff8880719126c8
RBP: ffffc90003d7f4f0 R08: dffffc0000000000 R09: ffffed100e3224da
R10: ffffed100e3224da R11: 1ffff1100e3224d9 R12: 0000000000000001
R13: 0000000000000002 R14: 0000000000000000 R15: ffff888071912688
FS:  000055555669a300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556ae87cf288 CR3: 000000001ca64000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	48 89 d8             	mov    %rbx,%rax
   3:	48 c1 e8 03          	shr    $0x3,%rax
   7:	42 80 3c 30 00       	cmpb   $0x0,(%rax,%r14,1)
   c:	74 08                	je     0x16
   e:	48 89 df             	mov    %rbx,%rdi
  11:	e8 8b b3 93 fe       	callq  0xfe93b3a1
  16:	4c 8b 33             	mov    (%rbx),%r14
  19:	4c 89 f0             	mov    %r14,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	4c 89 f7             	mov    %r14,%rdi
  33:	e8 69 b3 93 fe       	callq  0xfe93b3a1
  38:	4c 89 ff             	mov    %r15,%rdi
  3b:	4c 89 ee             	mov    %r13,%rsi
  3e:	44                   	rex.R
  3f:	89                   	.byte 0x89