syzbot

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 UID: 0 PID: 383 Comm: syz.2.17 Not tainted syzkaller #0 abd407d91653e73ff3b9de718fd37c0b8ddb7a3a
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__d_entry_type include/linux/dcache.h:414 [inline]
RIP: 0010:d_is_miss include/linux/dcache.h:419 [inline]
RIP: 0010:d_is_negative include/linux/dcache.h:465 [inline]
RIP: 0010:do_unlinkat+0x29c/0x5a0 fs/namei.c:4534
Code: 00 00 20 00 89 de e8 93 b8 98 ff 45 31 f6 81 fb 00 00 20 00 41 0f 95 c6 41 83 c6 eb 31 db e9 f4 00 00 00 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 04 02 00 00 41 8b 1f be 00 00 70 00 21
RSP: 0018:ffffc90000edfe00 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888114d54c00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000edfef8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520001dbf3c R12: ffff888124b62200
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000008
FS:  00007f3b50b076c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3b50ac4ff8 CR3: 0000000115650000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 __do_sys_unlink fs/namei.c:4589 [inline]
 __se_sys_unlink fs/namei.c:4587 [inline]
 __x64_sys_unlink+0x4b/0x60 fs/namei.c:4587
 x64_sys_call+0x286c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:88
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f3b4fb9ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3b50b07028 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007f3b4fe15fa0 RCX: 00007f3b4fb9ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000080
RBP: 00007f3b4fc32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3b4fe16038 R14: 00007f3b4fe15fa0 R15: 00007ffd10e2a018
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__d_entry_type include/linux/dcache.h:414 [inline]
RIP: 0010:d_is_miss include/linux/dcache.h:419 [inline]
RIP: 0010:d_is_negative include/linux/dcache.h:465 [inline]
RIP: 0010:do_unlinkat+0x29c/0x5a0 fs/namei.c:4534
Code: 00 00 20 00 89 de e8 93 b8 98 ff 45 31 f6 81 fb 00 00 20 00 41 0f 95 c6 41 83 c6 eb 31 db e9 f4 00 00 00 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 04 02 00 00 41 8b 1f be 00 00 70 00 21
RSP: 0018:ffffc90000edfe00 EFLAGS: 00010202

RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888114d54c00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000edfef8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520001dbf3c R12: ffff888124b62200
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000008
FS:  00007f3b50b076c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3b4fbea540 CR3: 0000000115650000 CR4: 00000000003526b0
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	20 00                	and    %al,(%rax)
   4:	89 de                	mov    %ebx,%esi
   6:	e8 93 b8 98 ff       	call   0xff98b89e
   b:	45 31 f6             	xor    %r14d,%r14d
   e:	81 fb 00 00 20 00    	cmp    $0x200000,%ebx
  14:	41 0f 95 c6          	setne  %r14b
  18:	41 83 c6 eb          	add    $0xffffffeb,%r14d
  1c:	31 db                	xor    %ebx,%ebx
  1e:	e9 f4 00 00 00       	jmp    0x117
  23:	4c 89 f8             	mov    %r15,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 04 02 00 00    	jne    0x23b
  37:	41 8b 1f             	mov    (%r15),%ebx
  3a:	be 00 00 70 00       	mov    $0x700000,%esi
  3f:	21                   	.byte 0x21