audit: type=1400 audit(1516309081.829:7): avc:  denied  { map } for  pid=3650 comm="syzkaller790771" path="/root/syzkaller790771206" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 3650 Comm: syzkaller790771 Not tainted 4.15.0-rc8+ #178
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:nfs_idmap_prepare_pipe_upcall fs/nfs/nfs4idmap.c:537 [inline]
RIP: 0010:nfs_idmap_legacy_upcall+0x290/0x4f0 fs/nfs/nfs4idmap.c:588
RSP: 0018:ffff8801bb487a38 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 1ffff10037690f49 RCX: ffffffff82083117
RDX: 0000000000000005 RSI: 1ffff1003775dd33 RDI: 0000000000000028
RBP: ffff8801bb487ad0 R08: 1ffff10037690ef6 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8801bc1da500 R14: 1ffff10037690f4d R15: ffff8801bba0b180
FS:  0000000000000000(0000) GS:ffff8801db200000(0063) knlGS:0000000008f06840
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000055a7fd4bb110 CR3: 00000001bbf7f003 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 construct_key security/keys/request_key.c:235 [inline]
 construct_key_and_link security/keys/request_key.c:484 [inline]
 request_key_and_link+0x10fd/0x16c0 security/keys/request_key.c:593
 SYSC_request_key security/keys/keyctl.c:213 [inline]
 SyS_request_key+0x18c/0x2d0 security/keys/keyctl.c:158
 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline]
 do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389
 entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:129
RIP: 0023:0xf7f8dc79
RSP: 002b:00000000ffab18ac EFLAGS: 00000286 ORIG_RAX: 000000000000011f
RAX: ffffffffffffffda RBX: 0000000020005ff6 RCX: 0000000020000000
RDX: 0000000020000000 RSI: 00000000fffffffe RDI: 00000000ffffffff
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Code: 89 85 68 ff ff ff 66 41 89 14 06 78 47 e8 79 f9 67 ff 48 8b 85 70 ff ff ff 48 8d 78 28 48 8b 85 68 ff ff ff 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 39 02 00 00 48 8b 85 70 ff ff ff 48 83 78 28 
RIP: nfs_idmap_prepare_pipe_upcall fs/nfs/nfs4idmap.c:537 [inline] RSP: ffff8801bb487a38
RIP: nfs_idmap_legacy_upcall+0x290/0x4f0 fs/nfs/nfs4idmap.c:588 RSP: ffff8801bb487a38
---[ end trace c86380b1794eb2ac ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..