BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
PGD 800000007e5b7067 P4D 800000007e5b7067 PUD 7e4d6067 PMD 0 
Oops: 0000 [#1] SMP PTI
CPU: 0 PID: 10704 Comm: syz-executor0 Not tainted 4.18.0-rc5+ #29
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:map_vm_area+0x69/0x1f0 mm/vmalloc.c:1340
Code: 08 48 89 45 a0 41 8b 84 24 90 0c 00 00 89 45 cc 45 8b bc 24 88 0c 00 00 e8 c4 44 b3 ff 4d 8d 75 08 48 85 db 0f 85 5b 01 00 00 <49> 8b 45 08 48 89 45 a8 4c 89 f7 e8 47 ef 0e 00 4d 8d 75 18 48 8b 
RSP: 0018:ffff88007c28f910 EFLAGS: 00010046
RAX: ffffffff81b4e03c RBX: 0000000000000000 RCX: 0000000000040000
RDX: ffffc900018bb000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffff88007c28f988 R08: 00000000004000c0 R09: ffff88021fc39090
R10: 0000000000000002 R11: 0000000000000000 R12: ffff88021fc39090
R13: 0000000000000000 R14: 0000000000000008 R15: 0000000000000000
FS:  00007f04f88b3700(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 000000007bfce000 CR4: 00000000001406f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 kmsan_vmap+0x134/0x200 mm/kmsan/kmsan_hooks.c:181
 vmap+0x3b2/0x540 mm/vmalloc.c:1648
 big_key_alloc_buffer+0x638/0xa30 security/keys/big_key.c:190
 big_key_read+0x1f5/0xad0 security/keys/big_key.c:375
 keyctl_read_key+0x47b/0x500 security/keys/keyctl.c:799
 __do_sys_keyctl security/keys/keyctl.c:1679 [inline]
 __se_sys_keyctl+0xc45/0x1980 security/keys/keyctl.c:1637
 __x64_sys_keyctl+0x15d/0x1b0 security/keys/keyctl.c:1637
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x455ab9
Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007f04f88b2c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000fa
RAX: ffffffffffffffda RBX: 00007f04f88b36d4 RCX: 0000000000455ab9
RDX: 00000000200014c0 RSI: 00000000072d1db9 RDI: 000000000000000b
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001000 R11: 0000000000000246 R12: 0000000000000014
R13: 00000000004bffde R14: 00000000004cf9d0 R15: 0000000000000006
Modules linked in:
Dumping ftrace buffer:
   (ftrace buffer empty)
CR2: 0000000000000008
---[ end trace 0ab81f3bbecb6d14 ]---
RIP: 0010:map_vm_area+0x69/0x1f0 mm/vmalloc.c:1340
Code: 08 48 89 45 a0 41 8b 84 24 90 0c 00 00 89 45 cc 45 8b bc 24 88 0c 00 00 e8 c4 44 b3 ff 4d 8d 75 08 48 85 db 0f 85 5b 01 00 00 <49> 8b 45 08 48 89 45 a8 4c 89 f7 e8 47 ef 0e 00 4d 8d 75 18 48 8b 
RSP: 0018:ffff88007c28f910 EFLAGS: 00010046
RAX: ffffffff81b4e03c RBX: 0000000000000000 RCX: 0000000000040000
RDX: ffffc900018bb000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffff88007c28f988 R08: 00000000004000c0 R09: ffff88021fc39090
R10: 0000000000000002 R11: 0000000000000000 R12: ffff88021fc39090
R13: 0000000000000000 R14: 0000000000000008 R15: 0000000000000000
FS:  00007f04f88b3700(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 000000007bfce000 CR4: 00000000001406f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600