incfs: ino conflict with backing FS 2
general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 PID: 22550 Comm: syz-executor.3 Not tainted 5.10.108-syzkaller-00653-gab2d1d40a128 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:mnt_want_write+0x2f/0x290 fs/namespace.c:354
Code: 57 41 56 41 55 41 54 53 50 48 89 fb 49 bc 00 00 00 00 00 fc ff df e8 90 2f b6 ff 48 89 5d d0 4c 8d 73 08 4d 89 f7 49 c1 ef 03 <43> 80 3c 27 00 74 08 4c 89 f7 e8 b2 35 f0 ff 4d 8b 2e 4d 8d a5 a8
RSP: 0018:ffffc90001d3fa90 EFLAGS: 00010202
RAX: ffffffff81b6c6a0 RBX: 0000000000000000 RCX: 0000000000040000
RDX: ffffc9000131c000 RSI: 00000000000000ed RDI: 00000000000000ee
RBP: ffffc90001d3fac0 R08: ffffffff8200a7d2 R09: 0000000000000003
R10: fffff520003a7f2f R11: 0000000000000004 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000008 R15: 0000000000000001
FS:  00007f573e627700(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33528000 CR3: 000000014b533000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ovl_want_write+0x91/0xa0 fs/overlayfs/util.c:21
 ovl_setattr+0x48/0x710 fs/overlayfs/inode.c:28
 notify_change+0xb78/0x1020 fs/attr.c:336
 incfs_setattr+0x225/0x3a0 fs/incfs/vfs.c:1609
 notify_change+0xb78/0x1020 fs/attr.c:336
 chmod_common+0x237/0x470 fs/open.c:584
 do_fchmodat fs/open.c:622 [inline]
 __do_sys_chmod fs/open.c:640 [inline]
 __se_sys_chmod fs/open.c:638 [inline]
 __x64_sys_chmod+0x10b/0x1c0 fs/open.c:638
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f573f4b1049
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007f573e627168 EFLAGS: 00000246 ORIG_RAX: 000000000000005a
RAX: ffffffffffffffda RBX: 00007f573f5c3f60 RCX: 00007f573f4b1049
RDX: 0000000000000000 RSI: 0000000000000020 RDI: 0000000020000280
RBP: 00007f573f50b08d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc5a75593f R14: 00007f573e627300 R15: 0000000000022000
Modules linked in:
---[ end trace 726bb587ac3dd00e ]---
RIP: 0010:mnt_want_write+0x2f/0x290 fs/namespace.c:354
Code: 57 41 56 41 55 41 54 53 50 48 89 fb 49 bc 00 00 00 00 00 fc ff df e8 90 2f b6 ff 48 89 5d d0 4c 8d 73 08 4d 89 f7 49 c1 ef 03 <43> 80 3c 27 00 74 08 4c 89 f7 e8 b2 35 f0 ff 4d 8b 2e 4d 8d a5 a8
RSP: 0018:ffffc90001d3fa90 EFLAGS: 00010202
RAX: ffffffff81b6c6a0 RBX: 0000000000000000 RCX: 0000000000040000
RDX: ffffc9000131c000 RSI: 00000000000000ed RDI: 00000000000000ee
RBP: ffffc90001d3fac0 R08: ffffffff8200a7d2 R09: 0000000000000003
R10: fffff520003a7f2f R11: 0000000000000004 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000008 R15: 0000000000000001
FS:  00007f573e627700(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555569b7b38 CR3: 000000014b533000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	57                   	push   %rdi
   1:	41 56                	push   %r14
   3:	41 55                	push   %r13
   5:	41 54                	push   %r12
   7:	53                   	push   %rbx
   8:	50                   	push   %rax
   9:	48 89 fb             	mov    %rdi,%rbx
   c:	49 bc 00 00 00 00 00 	movabs $0xdffffc0000000000,%r12
  13:	fc ff df
  16:	e8 90 2f b6 ff       	callq  0xffb62fab
  1b:	48 89 5d d0          	mov    %rbx,-0x30(%rbp)
  1f:	4c 8d 73 08          	lea    0x8(%rbx),%r14
  23:	4d 89 f7             	mov    %r14,%r15
  26:	49 c1 ef 03          	shr    $0x3,%r15
* 2a:	43 80 3c 27 00       	cmpb   $0x0,(%r15,%r12,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 f7             	mov    %r14,%rdi
  34:	e8 b2 35 f0 ff       	callq  0xfff035eb
  39:	4d 8b 2e             	mov    (%r14),%r13
  3c:	4d                   	rex.WRB
  3d:	8d                   	.byte 0x8d
  3e:	a5                   	movsl  %ds:(%rsi),%es:(%rdi)
  3f:	a8                   	.byte 0xa8