syzbot

general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f]
CPU: 1 PID: 302 Comm: syz-executor262 Not tainted 6.1.129-syzkaller-00054-g3e6e324f5b47 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:d_really_is_positive include/linux/dcache.h:493 [inline]
RIP: 0010:fuse_atomic_open+0x166/0x3a0 fs/fuse/dir.c:901
Code: 45 fe 8b 5d c4 89 de 83 e6 40 31 ff e8 93 56 5e ff 89 d8 83 e0 40 75 07 e8 d7 52 5e ff eb 25 49 8d 5f 30 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 cb ff a5 ff 48 83 3b 00 74 24 e8
RSP: 0018:ffffc90000e678d8 EFLAGS: 00010206
RAX: 0000000000000009 RBX: 000000000000004a RCX: ffff888110556540
RDX: ffff888110556540 RSI: 0000000000000040 RDI: 0000000000000000
RBP: ffffc90000e67930 R08: ffffffff821744ad R09: fffff520001cce65
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff88810fbeaa80 R14: 000000000000001a R15: 000000000000001a
FS:  00007f15623f16c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000b000 CR3: 0000000110491000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 atomic_open fs/namei.c:3344 [inline]
 lookup_open fs/namei.c:3452 [inline]
 open_last_lookups fs/namei.c:3549 [inline]
 path_openat+0xf52/0x2d60 fs/namei.c:3779
 do_filp_open+0x230/0x480 fs/namei.c:3809
 do_sys_openat2+0x151/0x870 fs/open.c:1341
 do_sys_open fs/open.c:1357 [inline]
 __do_sys_openat fs/open.c:1373 [inline]
 __se_sys_openat fs/open.c:1368 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1368
 x64_sys_call+0x6bf/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1562453759
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 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:00007f15623f1218 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f15624e33d8 RCX: 00007f1562453759
RDX: 0000000000000042 RSI: 0000200000000100 RDI: 00000000ffffff9c
RBP: 00007f15624e33d0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000001ff R11: 0000000000000246 R12: 00007f15624b0114
R13: 0000200000000100 R14: 0000000000000000 R15: 0030656c69662f2e
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:d_really_is_positive include/linux/dcache.h:493 [inline]
RIP: 0010:fuse_atomic_open+0x166/0x3a0 fs/fuse/dir.c:901
Code: 45 fe 8b 5d c4 89 de 83 e6 40 31 ff e8 93 56 5e ff 89 d8 83 e0 40 75 07 e8 d7 52 5e ff eb 25 49 8d 5f 30 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 cb ff a5 ff 48 83 3b 00 74 24 e8
RSP: 0018:ffffc90000e678d8 EFLAGS: 00010206
RAX: 0000000000000009 RBX: 000000000000004a RCX: ffff888110556540
RDX: ffff888110556540 RSI: 0000000000000040 RDI: 0000000000000000
RBP: ffffc90000e67930 R08: ffffffff821744ad R09: fffff520001cce65
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff88810fbeaa80 R14: 000000000000001a R15: 000000000000001a
FS:  00007f15623f16c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000b000 CR3: 0000000110491000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	45 fe 8b 5d c4 89 de 	rex.RB decb -0x21763ba3(%r11)
   7:	83 e6 40             	and    $0x40,%esi
   a:	31 ff                	xor    %edi,%edi
   c:	e8 93 56 5e ff       	call   0xff5e56a4
  11:	89 d8                	mov    %ebx,%eax
  13:	83 e0 40             	and    $0x40,%eax
  16:	75 07                	jne    0x1f
  18:	e8 d7 52 5e ff       	call   0xff5e52f4
  1d:	eb 25                	jmp    0x44
  1f:	49 8d 5f 30          	lea    0x30(%r15),%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 cb ff a5 ff       	call   0xffa60004
  39:	48 83 3b 00          	cmpq   $0x0,(%rbx)
  3d:	74 24                	je     0x63
  3f:	e8                   	.byte 0xe8