BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 3b2db067 P4D 3b2db067 PUD 0 
Oops: Oops: 0010 [#1] SMP KASAN NOPTI
CPU: 3 UID: 0 PID: 10183 Comm: syz.3.1199 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:ffffc900039e79d8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880329a46f0 RCX: ffffc9000561a000
RDX: 0000000000080000 RSI: ffffffff82c4de2c RDI: ffff8880329a4640
RBP: 000000000017d200 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880329a46d8
R13: dffffc0000000000 R14: ffff8880329a4640 R15: ffff88802e2e52c0
FS:  00007fc3bedea6c0(0000) GS:ffff8880d663f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000003846a000 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
 do_iter_readv_writev+0x6ee/0x920 fs/read_write.c:829
 vfs_writev+0x360/0xe10 fs/read_write.c:1059
 do_writev+0x13e/0x340 fs/read_write.c:1105
 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: 0033:0x7fc3bdf9c799
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:00007fc3bedea028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007fc3be215fa0 RCX: 00007fc3bdf9c799
RDX: 0000000000000021 RSI: 0000200000000a40 RDI: 0000000000000009
RBP: 00007fc3be032c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc3be216038 R14: 00007fc3be215fa0 R15: 00007ffc70c97df8
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc900039e79d8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880329a46f0 RCX: ffffc9000561a000
RDX: 0000000000080000 RSI: ffffffff82c4de2c RDI: ffff8880329a4640
RBP: 000000000017d200 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880329a46d8
R13: dffffc0000000000 R14: ffff8880329a4640 R15: ffff88802e2e52c0
FS:  00007fc3bedea6c0(0000) GS:ffff8880d663f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000003846a000 CR4: 0000000000352ef0