syzbot

general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
CPU: 0 PID: 291 Comm: syz-executor236 Not tainted 5.15.189-syzkaller-android13-5.15.189_r00 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:d_really_is_positive include/linux/dcache.h:503 [inline]
RIP: 0010:fuse_atomic_open+0x238/0x2140 fs/fuse/dir.c:875
Code: 89 de 83 e6 40 31 ff e8 56 f8 71 ff 89 d8 83 e0 40 75 07 e8 9a f4 71 ff eb 2e 48 8b 44 24 58 48 8d 58 30 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 59 6f b0 ff 48 83 3b 00 0f 84 9c
RSP: 0018:ffffc90000997380 EFLAGS: 00010207
RAX: 0000000000000006 RBX: 0000000000000035 RCX: ffff888106bae2c0
RDX: 0000000000000000 RSI: 0000000000000040 RDI: 0000000000000000
RBP: ffffc900009979b0 R08: ffff888106bae2c0 R09: 0000000000000002
R10: 00000000fffffffe R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888120777800 R14: 1ffff92000132e88 R15: 0000000000000005
FS:  00007fd6ef2d16c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c224b92eb8 CR3: 0000000120795000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 atomic_open fs/namei.c:3325 [inline]
 lookup_open fs/namei.c:3433 [inline]
 open_last_lookups fs/namei.c:3532 [inline]
 path_openat+0xe31/0x2f10 fs/namei.c:3739
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
 do_sys_openat2+0x14c/0x7b0 fs/open.c:1234
 do_sys_open fs/open.c:1250 [inline]
 __do_sys_creat fs/open.c:1326 [inline]
 __se_sys_creat fs/open.c:1320 [inline]
 __x64_sys_creat+0x8e/0xb0 fs/open.c:1320
 x64_sys_call+0x94a/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:86
 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: 0033:0x7fd6ef3304f9
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:00007fd6ef2d1218 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007fd6ef3bd3f8 RCX: 00007fd6ef3304f9
RDX: 00007fd6ef3304f9 RSI: 0000000000000000 RDI: 0000200000000180
RBP: 00007fd6ef3bd3f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd6ef38a034
R13: 0000200000004380 R14: 0000200000000180 R15: 00007ffef0c7a918
 </TASK>
Modules linked in:
---[ end trace d7f333bc7fad4f0d ]---
RIP: 0010:d_really_is_positive include/linux/dcache.h:503 [inline]
RIP: 0010:fuse_atomic_open+0x238/0x2140 fs/fuse/dir.c:875
Code: 89 de 83 e6 40 31 ff e8 56 f8 71 ff 89 d8 83 e0 40 75 07 e8 9a f4 71 ff eb 2e 48 8b 44 24 58 48 8d 58 30 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 59 6f b0 ff 48 83 3b 00 0f 84 9c
RSP: 0018:ffffc90000997380 EFLAGS: 00010207

RAX: 0000000000000006 RBX: 0000000000000035 RCX: ffff888106bae2c0
RDX: 0000000000000000 RSI: 0000000000000040 RDI: 0000000000000000
RBP: ffffc900009979b0 R08: ffff888106bae2c0 R09: 0000000000000002
R10: 00000000fffffffe R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888120777800 R14: 1ffff92000132e88 R15: 0000000000000005
FS:  00007fd6ef2d16c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffef0dea080 CR3: 0000000120795000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	89 de                	mov    %ebx,%esi
   2:	83 e6 40             	and    $0x40,%esi
   5:	31 ff                	xor    %edi,%edi
   7:	e8 56 f8 71 ff       	call   0xff71f862
   c:	89 d8                	mov    %ebx,%eax
   e:	83 e0 40             	and    $0x40,%eax
  11:	75 07                	jne    0x1a
  13:	e8 9a f4 71 ff       	call   0xff71f4b2
  18:	eb 2e                	jmp    0x48
  1a:	48 8b 44 24 58       	mov    0x58(%rsp),%rax
  1f:	48 8d 58 30          	lea    0x30(%rax),%rbx
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 59 6f b0 ff       	call   0xffb06f92
  39:	48 83 3b 00          	cmpq   $0x0,(%rbx)
  3d:	0f                   	.byte 0xf
  3e:	84                   	.byte 0x84
  3f:	9c                   	pushf