general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 PID: 984 Comm: kworker/u4:4 Not tainted 5.16.0-rc4-next-20211207-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
RIP: 0010:nfsd_reply_cache_free_locked+0x31/0x3b0 fs/nfsd/nfscache.c:123
Code: 54 49 89 fc 55 48 89 f5 53 48 89 d3 48 83 ec 08 e8 64 ff 11 ff 48 8d 7d 61 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 c3 02 00 00
RSP: 0018:ffffc90004defb68 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88807dbce000 RCX: 0000000000000000
RDX: 0000000000000002 RSI: ffffffff8265e44c RDI: 0000000000000011
RBP: ffffffffffffffb0 R08: 0000000000000800 R09: ffffffff8ff9494f
R10: ffffffff8265f31e R11: 000000000008808a R12: ffff888000102730
R13: 0000000000002730 R14: ffffed10000204e7 R15: ffff888000102730
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffb7099c718 CR3: 000000002f777000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 nfsd_reply_cache_shutdown+0x153/0x2d0 fs/nfsd/nfscache.c:222
 nfsd_exit_net+0x10e/0x4b0 fs/nfsd/nfsctl.c:1502
 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:168
 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:593
 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2318
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2465
 kthread+0x405/0x4f0 kernel/kthread.c:345
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Modules linked in:
---[ end trace 1f50c0663e8c983d ]---
RIP: 0010:nfsd_reply_cache_free_locked+0x31/0x3b0 fs/nfsd/nfscache.c:123
Code: 54 49 89 fc 55 48 89 f5 53 48 89 d3 48 83 ec 08 e8 64 ff 11 ff 48 8d 7d 61 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 c3 02 00 00
RSP: 0018:ffffc90004defb68 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88807dbce000 RCX: 0000000000000000
RDX: 0000000000000002 RSI: ffffffff8265e44c RDI: 0000000000000011
RBP: ffffffffffffffb0 R08: 0000000000000800 R09: ffffffff8ff9494f
R10: ffffffff8265f31e R11: 000000000008808a R12: ffff888000102730
R13: 0000000000002730 R14: ffffed10000204e7 R15: ffff888000102730
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efd5b31c000 CR3: 000000002f499000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	54                   	push   %rsp
   1:	49 89 fc             	mov    %rdi,%r12
   4:	55                   	push   %rbp
   5:	48 89 f5             	mov    %rsi,%rbp
   8:	53                   	push   %rbx
   9:	48 89 d3             	mov    %rdx,%rbx
   c:	48 83 ec 08          	sub    $0x8,%rsp
  10:	e8 64 ff 11 ff       	callq  0xff11ff79
  15:	48 8d 7d 61          	lea    0x61(%rbp),%rdi
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax <-- trapping instruction
  2e:	48 89 fa             	mov    %rdi,%rdx
  31:	83 e2 07             	and    $0x7,%edx
  34:	38 d0                	cmp    %dl,%al
  36:	7f 08                	jg     0x40
  38:	84 c0                	test   %al,%al
  3a:	0f 85 c3 02 00 00    	jne    0x303