==================================================================
BUG: KFENCE: use-after-free read in kvm_fastop_exception+0xf58/0x1045

Use-after-free read at 0xffff88823bc2a020 (in kfence-#20):
 kvm_fastop_exception+0xf58/0x1045
 d_lookup+0x72/0xd0 fs/dcache.c:2370
 lookup_dcache+0x14/0xd0 fs/namei.c:1520
 __lookup_hash+0x1b/0x140 fs/namei.c:1543
 kern_path_locked+0x146/0x300 fs/namei.c:2567
 handle_remove+0x9a/0x4fa drivers/base/devtmpfs.c:312
 handle drivers/base/devtmpfs.c:382 [inline]
 devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline]
 devtmpfsd+0x176/0x24e drivers/base/devtmpfs.c:437
 kthread+0x38b/0x460 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

kfence-#20: 0xffff88823bc2a000-0xffff88823bc2afff, size=4096, cache=names_cache

allocated by task 22 on cpu 0 at 69.151391s:
 getname_kernel+0x48/0x330 fs/namei.c:226
 kern_path_locked+0x6f/0x300 fs/namei.c:2558
 handle_remove+0x9a/0x4fa drivers/base/devtmpfs.c:312
 handle drivers/base/devtmpfs.c:382 [inline]
 devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline]
 devtmpfsd+0x176/0x24e drivers/base/devtmpfs.c:437
 kthread+0x38b/0x460 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

freed by task 22 on cpu 0 at 69.151414s:
 putname include/linux/err.h:41 [inline]
 filename_parentat fs/namei.c:2547 [inline]
 kern_path_locked+0xa7/0x300 fs/namei.c:2558
 handle_remove+0x9a/0x4fa drivers/base/devtmpfs.c:312
 handle drivers/base/devtmpfs.c:382 [inline]
 devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline]
 devtmpfsd+0x176/0x24e drivers/base/devtmpfs.c:437
 kthread+0x38b/0x460 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

CPU: 0 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:kvm_fastop_exception+0xf58/0x1045
Code: 49 d3 eb e9 c9 b2 15 f9 48 8d 0b 48 83 e1 f8 48 8b 31 8d 0b 83 e1 07 c1 e1 03 48 d3 ee e9 c5 bc 15 f9 48 8d 4d 00 48 83 e1 f8 <4c> 8b 11 8d 4d 00 83 e1 07 c1 e1 03 49 d3 ea e9 27 c5 15 f9 b8 f2
RSP: 0018:ffffc90000dcfb10 EFLAGS: 00010282
RAX: 0000003336706174 RBX: ffff88806fe884d8 RCX: ffff88823bc2a020
RDX: ffffed100dfd109c RSI: 0000000000000001 RDI: ffff88806fe884d8
RBP: ffff88823bc2a020 R08: 0000000000000000 R09: ffff88806fe884d8
R10: ffffed100dfd109b R11: 0000000000000001 R12: dffffc0000000000
R13: 0000000000000005 R14: 0000000000000005 R15: ffff88806fe884a8
FS:  0000000000000000(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88823bc2a020 CR3: 000000006f075000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 d_lookup+0x72/0xd0 fs/dcache.c:2370
 lookup_dcache+0x14/0xd0 fs/namei.c:1520
 __lookup_hash+0x1b/0x140 fs/namei.c:1543
 kern_path_locked+0x146/0x300 fs/namei.c:2567
 handle_remove+0x9a/0x4fa drivers/base/devtmpfs.c:312
 handle drivers/base/devtmpfs.c:382 [inline]
 devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline]
 devtmpfsd+0x176/0x24e drivers/base/devtmpfs.c:437
 kthread+0x38b/0x460 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
==================================================================
----------------
Code disassembly (best guess):
   0:	49 d3 eb             	shr    %cl,%r11
   3:	e9 c9 b2 15 f9       	jmpq   0xf915b2d1
   8:	48 8d 0b             	lea    (%rbx),%rcx
   b:	48 83 e1 f8          	and    $0xfffffffffffffff8,%rcx
   f:	48 8b 31             	mov    (%rcx),%rsi
  12:	8d 0b                	lea    (%rbx),%ecx
  14:	83 e1 07             	and    $0x7,%ecx
  17:	c1 e1 03             	shl    $0x3,%ecx
  1a:	48 d3 ee             	shr    %cl,%rsi
  1d:	e9 c5 bc 15 f9       	jmpq   0xf915bce7
  22:	48 8d 4d 00          	lea    0x0(%rbp),%rcx
  26:	48 83 e1 f8          	and    $0xfffffffffffffff8,%rcx
* 2a:	4c 8b 11             	mov    (%rcx),%r10 <-- trapping instruction
  2d:	8d 4d 00             	lea    0x0(%rbp),%ecx
  30:	83 e1 07             	and    $0x7,%ecx
  33:	c1 e1 03             	shl    $0x3,%ecx
  36:	49 d3 ea             	shr    %cl,%r10
  39:	e9 27 c5 15 f9       	jmpq   0xf915c565
  3e:	b8                   	.byte 0xb8
  3f:	f2                   	repnz