syzbot

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 0 UID: 0 PID: 5320 Comm: syz.0.0 Not tainted 6.13.0-rc5-syzkaller-00161-g63676eefb7a0 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:exfat_get_dentry_cached fs/exfat/dir.c:727 [inline]
RIP: 0010:exfat_init_dir_entry+0x556/0x9c0 fs/exfat/dir.c:460
Code: 48 98 49 8d 1c c7 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 48 31 8b ff 48 8b 1b 48 83 c3 28 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 2b 31 8b ff 4c 8b 3b 42 80 7c 2d
RSP: 0018:ffffc9000d55f2f8 EFLAGS: 00010206
RAX: 0000000000000005 RBX: 0000000000000028 RCX: 0000000000000009
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000000000000020
RBP: 1ffff92001aabedc R08: ffffffff827abaa7 R09: 0000000000000000
R10: ffffc9000d55f240 R11: fffff52001aabe4d R12: 0000000000000200
R13: dffffc0000000000 R14: ffff888040b4a000 R15: ffffc9000d55f6f0
FS:  00007f2a4feda6c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000003d530000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 exfat_add_entry+0x516/0xaa0 fs/exfat/namei.c:516
 exfat_create+0x1c7/0x570 fs/exfat/namei.c:565
 lookup_open fs/namei.c:3649 [inline]
 open_last_lookups fs/namei.c:3748 [inline]
 path_openat+0x1c03/0x3590 fs/namei.c:3984
 do_filp_open+0x27f/0x4e0 fs/namei.c:4014
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402
 do_sys_open fs/open.c:1417 [inline]
 __do_sys_openat fs/open.c:1433 [inline]
 __se_sys_openat fs/open.c:1428 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1428
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2a4f185d29
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:00007f2a4feda038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f2a4f376160 RCX: 00007f2a4f185d29
RDX: 000000000000275a RSI: 00000000200000c0 RDI: ffffffffffffff9c
RBP: 00007f2a4f201b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f2a4f376160 R15: 00007ffccc2ed838
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:exfat_get_dentry_cached fs/exfat/dir.c:727 [inline]
RIP: 0010:exfat_init_dir_entry+0x556/0x9c0 fs/exfat/dir.c:460
Code: 48 98 49 8d 1c c7 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 48 31 8b ff 48 8b 1b 48 83 c3 28 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 2b 31 8b ff 4c 8b 3b 42 80 7c 2d
RSP: 0018:ffffc9000d55f2f8 EFLAGS: 00010206
RAX: 0000000000000005 RBX: 0000000000000028 RCX: 0000000000000009
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000000000000020
RBP: 1ffff92001aabedc R08: ffffffff827abaa7 R09: 0000000000000000
R10: ffffc9000d55f240 R11: fffff52001aabe4d R12: 0000000000000200
R13: dffffc0000000000 R14: ffff888040b4a000 R15: ffffc9000d55f6f0
FS:  00007f2a4feda6c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000003d530000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	48 98                	cltq
   2:	49 8d 1c c7          	lea    (%r15,%rax,8),%rbx
   6:	48 89 d8             	mov    %rbx,%rax
   9:	48 c1 e8 03          	shr    $0x3,%rax
   d:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
  12:	74 08                	je     0x1c
  14:	48 89 df             	mov    %rbx,%rdi
  17:	e8 48 31 8b ff       	call   0xff8b3164
  1c:	48 8b 1b             	mov    (%rbx),%rbx
  1f:	48 83 c3 28          	add    $0x28,%rbx
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 2b 31 8b ff       	call   0xff8b3164
  39:	4c 8b 3b             	mov    (%rbx),%r15
  3c:	42                   	rex.X
  3d:	80                   	.byte 0x80
  3e:	7c 2d                	jl     0x6d