Oops: general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047]
CPU: 1 UID: 0 PID: 5927 Comm: nfsd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:nfsd_file_net_dispose+0xa6/0x460
Code: 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 11 db 4d ff 49 8b 06 48 89 04 24 4c 8d 70 40 4c 89 f0 48 c1 e8 03 48 89 44 24 10 <42> 80 3c 20 00 74 08 4c 89 f7 e8 eb da 4d ff 49 8b 06 4c 39 f0 0f
RSP: 0018:ffffc90007297c20 EFLAGS: 00010202
RAX: 0000000000000008 RBX: ffff888115834000 RCX: ffff88810fb55a00
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888115834000
RBP: ffffc90007297cd0 R08: ffff88817366219f R09: 1ffff1102e6cc433
R10: dffffc0000000000 R11: ffffed102e6cc434 R12: dffffc0000000000
R13: ffff888120bc7430 R14: 0000000000000040 R15: ffff888173662198
FS:  0000000000000000(0000) GS:ffff8882a8f39000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3e3d02 CR3: 000000011c6b2000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 nfsd+0x2ed/0xbb0
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:nfsd_file_net_dispose+0xa6/0x460
Code: 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 11 db 4d ff 49 8b 06 48 89 04 24 4c 8d 70 40 4c 89 f0 48 c1 e8 03 48 89 44 24 10 <42> 80 3c 20 00 74 08 4c 89 f7 e8 eb da 4d ff 49 8b 06 4c 39 f0 0f
RSP: 0018:ffffc90007297c20 EFLAGS: 00010202
RAX: 0000000000000008 RBX: ffff888115834000 RCX: ffff88810fb55a00
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888115834000
RBP: ffffc90007297cd0 R08: ffff88817366219f R09: 1ffff1102e6cc433
R10: dffffc0000000000 R11: ffffed102e6cc434 R12: dffffc0000000000
R13: ffff888120bc7430 R14: 0000000000000040 R15: ffff888173662198
FS:  0000000000000000(0000) GS:ffff8882a8f39000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555687eaa28 CR3: 00000001701b2000 CR4: 00000000000006f0
