general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 1 PID: 345 Comm: syz-executor.0 Not tainted 5.15.188-syzkaller-1081189-g6b619c45dff5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:traverse_mounts fs/namei.c:1378 [inline]
RIP: 0010:handle_mounts fs/namei.c:1498 [inline]
RIP: 0010:step_into+0x12e/0xd10 fs/namei.c:1806
Code: 4c 8b 74 24 18 c6 44 24 7f 00 43 0f b6 44 25 00 84 c0 0f 85 6f 0a 00 00 45 8b 36 4c 8b bc 24 a8 00 00 00 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 6e 0a 00 00 45 8b 3f 44 89 fe 81 e6 00
RSP: 0018:ffffc90000dc7a60 EFLAGS: 00010207
RAX: 0000000000000003 RBX: ffffc90000dc7ca0 RCX: ffff88810d9b13c0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000dc7b68 R08: 0000000000000000 R09: ffffed1021b36006
R10: ffffed1021b36006 R11: 1ffff11021b36005 R12: dffffc0000000000
R13: 1ffff920001b8f9b R14: 0000000000000081 R15: 000000000000001e
FS:  00007f6a5991f6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020005000 CR3: 000000011de0f000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 walk_component+0x26a/0x460 fs/namei.c:1982
 lookup_last fs/namei.c:2431 [inline]
 path_lookupat+0x180/0x490 fs/namei.c:2455
 filename_lookup+0x1e2/0x4f0 fs/namei.c:2484
 user_path_at_empty+0x47/0x1c0 fs/namei.c:2883
 user_path_at include/linux/namei.h:57 [inline]
 ksys_umount fs/namespace.c:1777 [inline]
 __do_sys_umount fs/namespace.c:1785 [inline]
 __se_sys_umount fs/namespace.c:1783 [inline]
 __x64_sys_umount+0xf1/0x160 fs/namespace.c:1783
 x64_sys_call+0x8b7/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:167
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f6a59d9cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6a5991f0c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 00007f6a59ebbf80 RCX: 00007f6a59d9cae9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000020000080
RBP: 00007f6a59de847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f6a59ebbf80 R15: 00007ffd527c9c08
 </TASK>
Modules linked in:
---[ end trace c2c72b3049d50db8 ]---
RIP: 0010:traverse_mounts fs/namei.c:1378 [inline]
RIP: 0010:handle_mounts fs/namei.c:1498 [inline]
RIP: 0010:step_into+0x12e/0xd10 fs/namei.c:1806
Code: 4c 8b 74 24 18 c6 44 24 7f 00 43 0f b6 44 25 00 84 c0 0f 85 6f 0a 00 00 45 8b 36 4c 8b bc 24 a8 00 00 00 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 6e 0a 00 00 45 8b 3f 44 89 fe 81 e6 00
RSP: 0018:ffffc90000dc7a60 EFLAGS: 00010207
RAX: 0000000000000003 RBX: ffffc90000dc7ca0 RCX: ffff88810d9b13c0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000dc7b68 R08: 0000000000000000 R09: ffffed1021b36006
R10: ffffed1021b36006 R11: 1ffff11021b36005 R12: dffffc0000000000
R13: 1ffff920001b8f9b R14: 0000000000000081 R15: 000000000000001e
FS:  00007f6a5991f6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020005000 CR3: 000000011de0f000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	4c 8b 74 24 18       	mov    0x18(%rsp),%r14
   5:	c6 44 24 7f 00       	movb   $0x0,0x7f(%rsp)
   a:	43 0f b6 44 25 00    	movzbl 0x0(%r13,%r12,1),%eax
  10:	84 c0                	test   %al,%al
  12:	0f 85 6f 0a 00 00    	jne    0xa87
  18:	45 8b 36             	mov    (%r14),%r14d
  1b:	4c 8b bc 24 a8 00 00 	mov    0xa8(%rsp),%r15
  22:	00
  23:	4c 89 f8             	mov    %r15,%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:	0f 85 6e 0a 00 00    	jne    0xaa5
  37:	45 8b 3f             	mov    (%r15),%r15d
  3a:	44 89 fe             	mov    %r15d,%esi
  3d:	81                   	.byte 0x81
  3e:	e6 00                	out    %al,$0x0