BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 50457067 P4D 50457067 PUD 0 
Oops: Oops: 0010 [#1] SMP KASAN NOPTI
CPU: 3 UID: 0 PID: 11186 Comm: syz.6.1637 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc90005a07b90 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880638186f0 RCX: ffffc9000c001000
RDX: 0000000000080000 RSI: ffffffff82c4d95c RDI: ffff888063818640
RBP: 00000000007fffc0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880638186d8
R13: dffffc0000000000 R14: ffff888063818640 R15: ffff88802257a1c0
FS:  00007f98de61a6c0(0000) GS:ffff8880d663f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000002e397000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 netfs_unbuffered_write+0xae5/0x2080 fs/netfs/direct_write.c:189
 netfs_unbuffered_write_iter_locked+0x801/0xab0 fs/netfs/direct_write.c:287
 netfs_unbuffered_write_iter+0x40c/0x710 fs/netfs/direct_write.c:377
 v9fs_file_write_iter+0xbf/0x100 fs/9p/vfs_file.c:409
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1070 fs/read_write.c:688
 ksys_write+0x12a/0x250 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f98dd79c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f98de61a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f98dda16090 RCX: 00007f98dd79c799
RDX: 000000000208e24b RSI: 0000200000000040 RDI: 0000000000000007
RBP: 00007f98dd832c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f98dda16128 R14: 00007f98dda16090 R15: 00007ffd725129c8
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc90005a07b90 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880638186f0 RCX: ffffc9000c001000
RDX: 0000000000080000 RSI: ffffffff82c4d95c RDI: ffff888063818640
RBP: 00000000007fffc0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880638186d8
R13: dffffc0000000000 R14: ffff888063818640 R15: ffff88802257a1c0
FS:  00007f98de61a6c0(0000) GS:ffff8880d663f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000002e397000 CR4: 0000000000352ef0