syzbot

Oops: general protection fault, probably for non-canonical address 0xdffffc000000000d: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
CPU: 0 UID: 0 PID: 11921 Comm: syz.4.1860 Not tainted 6.14.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:__d_unalias fs/dcache.c:2969 [inline]
RIP: 0010:d_splice_alias+0x9cd/0xf30 fs/dcache.c:3037
Code: 48 c1 ea 03 80 3c 02 00 0f 85 4e 05 00 00 49 8b 85 70 ff ff ff 48 ba 00 00 00 00 00 fc ff df 48 8d 78 68 48 89 f9 48 c1 e9 03 <80> 3c 11 00 0f 85 14 05 00 00 48 8b 40 68 48 85 c0 74 31 48 89 44
RSP: 0018:ffffc900040e76e8 EFLAGS: 00010212
RAX: 0000000000000000 RBX: ffff888056477d60 RCX: 000000000000000d
RDX: dffffc0000000000 RSI: ffffffff8234b06c RDI: 0000000000000068
RBP: ffff88805494a138 R08: 0000000000000000 R09: ffffed100ac8ee4b
R10: ffff88805647725b R11: 00000000000000c3 R12: ffff8880564771a0
R13: ffff88805647db98 R14: ffff88805647da70 R15: ffff88805647db08
FS:  00007f0b6266d6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000055bf2000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 udf_lookup+0x191/0x240 fs/udf/namei.c:130
 __lookup_slow+0x252/0x470 fs/namei.c:1793
 lookup_slow fs/namei.c:1810 [inline]
 walk_component+0x350/0x5b0 fs/namei.c:2114
 link_path_walk.part.0.constprop.0+0x669/0xd40 fs/namei.c:2479
 link_path_walk fs/namei.c:2411 [inline]
 path_parentat+0xaa/0x1b0 fs/namei.c:2683
 __filename_parentat+0x22d/0x680 fs/namei.c:2707
 filename_parentat fs/namei.c:2725 [inline]
 do_renameat2+0x25a/0xdd0 fs/namei.c:5138
 __do_sys_rename fs/namei.c:5273 [inline]
 __se_sys_rename fs/namei.c:5271 [inline]
 __x64_sys_rename+0x7d/0xa0 fs/namei.c:5271
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0b6178cda9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0b6266d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007f0b619a6080 RCX: 00007f0b6178cda9
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000020000000
RBP: 00007f0b6180e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f0b619a6080 R15: 00007ffc29bd3628
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__d_unalias fs/dcache.c:2969 [inline]
RIP: 0010:d_splice_alias+0x9cd/0xf30 fs/dcache.c:3037
Code: 48 c1 ea 03 80 3c 02 00 0f 85 4e 05 00 00 49 8b 85 70 ff ff ff 48 ba 00 00 00 00 00 fc ff df 48 8d 78 68 48 89 f9 48 c1 e9 03 <80> 3c 11 00 0f 85 14 05 00 00 48 8b 40 68 48 85 c0 74 31 48 89 44
RSP: 0018:ffffc900040e76e8 EFLAGS: 00010212
RAX: 0000000000000000 RBX: ffff888056477d60 RCX: 000000000000000d
RDX: dffffc0000000000 RSI: ffffffff8234b06c RDI: 0000000000000068
RBP: ffff88805494a138 R08: 0000000000000000 R09: ffffed100ac8ee4b
R10: ffff88805647725b R11: 00000000000000c3 R12: ffff8880564771a0
R13: ffff88805647db98 R14: ffff88805647da70 R15: ffff88805647db08
FS:  00007f0b6266d6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000055bf2000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
   0:	48 c1 ea 03          	shr    $0x3,%rdx
   4:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   8:	0f 85 4e 05 00 00    	jne    0x55c
   e:	49 8b 85 70 ff ff ff 	mov    -0x90(%r13),%rax
  15:	48 ba 00 00 00 00 00 	movabs $0xdffffc0000000000,%rdx
  1c:	fc ff df
  1f:	48 8d 78 68          	lea    0x68(%rax),%rdi
  23:	48 89 f9             	mov    %rdi,%rcx
  26:	48 c1 e9 03          	shr    $0x3,%rcx
* 2a:	80 3c 11 00          	cmpb   $0x0,(%rcx,%rdx,1) <-- trapping instruction
  2e:	0f 85 14 05 00 00    	jne    0x548
  34:	48 8b 40 68          	mov    0x68(%rax),%rax
  38:	48 85 c0             	test   %rax,%rax
  3b:	74 31                	je     0x6e
  3d:	48                   	rex.W
  3e:	89                   	.byte 0x89
  3f:	44                   	rex.R