syzbot

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: 299 Comm: syz-executor214 Not tainted 5.15.178-syzkaller-00034-g5e1b899f19c3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__d_entry_type include/linux/dcache.h:404 [inline]
RIP: 0010:d_is_miss include/linux/dcache.h:409 [inline]
RIP: 0010:d_is_negative include/linux/dcache.h:455 [inline]
RIP: 0010:d_is_positive include/linux/dcache.h:465 [inline]
RIP: 0010:filename_create+0x2d8/0x530 fs/namei.c:3842
Code: 92 00 00 00 4c 89 7c 24 28 45 84 e4 0f 95 c0 83 7c 24 14 00 0f 94 c3 20 c3 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 1f 02 00 00 45 8b 26 41 bd 00 00 70 00 be
RSP: 0018:ffffc90000997cc0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff92000132f00 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000000
RBP: ffffc90000997db0 R08: ffffffff81c10068 R09: ffffed10243b2494
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: 0000000000000600 R14: 0000000000000002 R15: ffffc90000997e60
FS:  00007fdc903aa6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdc903aad58 CR3: 00000001065d5000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 do_linkat+0x210/0x9f0 fs/namei.c:4612
 __do_sys_link fs/namei.c:4662 [inline]
 __se_sys_link fs/namei.c:4660 [inline]
 __x64_sys_link+0x86/0x90 fs/namei.c:4660
 x64_sys_call+0x282/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:87
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fdc9042a879
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 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:00007fdc903aa218 EFLAGS: 00000246 ORIG_RAX: 0000000000000056
RAX: ffffffffffffffda RBX: 00007fdc904bb408 RCX: 00007fdc9042a879
RDX: 00007fdc90407ff6 RSI: 0000200000000400 RDI: 0000200000000280
RBP: 00007fdc904bb400 R08: 00007ffef44f2137 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdc904880bc
R13: 000020000000a280 R14: 00007ffef44f2050 R15: 00007ffef44f2138
 </TASK>
Modules linked in:
---[ end trace a8550e13a5c483dc ]---
RIP: 0010:__d_entry_type include/linux/dcache.h:404 [inline]
RIP: 0010:d_is_miss include/linux/dcache.h:409 [inline]
RIP: 0010:d_is_negative include/linux/dcache.h:455 [inline]
RIP: 0010:d_is_positive include/linux/dcache.h:465 [inline]
RIP: 0010:filename_create+0x2d8/0x530 fs/namei.c:3842
Code: 92 00 00 00 4c 89 7c 24 28 45 84 e4 0f 95 c0 83 7c 24 14 00 0f 94 c3 20 c3 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 1f 02 00 00 45 8b 26 41 bd 00 00 70 00 be
RSP: 0018:ffffc90000997cc0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff92000132f00 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000000
RBP: ffffc90000997db0 R08: ffffffff81c10068 R09: ffffed10243b2494
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: 0000000000000600 R14: 0000000000000002 R15: ffffc90000997e60
FS:  00007fdc903aa6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdc90481458 CR3: 00000001065d5000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	92                   	xchg   %eax,%edx
   1:	00 00                	add    %al,(%rax)
   3:	00 4c 89 7c          	add    %cl,0x7c(%rcx,%rcx,4)
   7:	24 28                	and    $0x28,%al
   9:	45 84 e4             	test   %r12b,%r12b
   c:	0f 95 c0             	setne  %al
   f:	83 7c 24 14 00       	cmpl   $0x0,0x14(%rsp)
  14:	0f 94 c3             	sete   %bl
  17:	20 c3                	and    %al,%bl
  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:	0f b6 04 08          	movzbl (%rax,%rcx,1),%eax <-- trapping instruction
  2e:	84 c0                	test   %al,%al
  30:	0f 85 1f 02 00 00    	jne    0x255
  36:	45 8b 26             	mov    (%r14),%r12d
  39:	41 bd 00 00 70 00    	mov    $0x700000,%r13d
  3f:	be                   	.byte 0xbe