BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 0 P4D 0 
Oops: Oops: 0010 [#1] SMP KASAN NOPTI
CPU: 3 UID: 0 PID: 13 Comm: kworker/u32:1 Not tainted 6.15.0-rc2-syzkaller-00471-g119009db2674 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: loop8 loop_rootcg_workfn
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0000:ffffc90000107a38 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffff8beceec0 RCX: ffffffff86084265
RDX: 1ffffffff17d9ddd RSI: ffffc90000107b28 RDI: ffff888025fe3128
RBP: ffff888025fe3128 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000002be0 R12: ffffc90000107b28
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880d6cb2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000001caa6000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lo_rw_aio.isra.0+0x9c2/0xd90 drivers/block/loop.c:393
 do_req_filebacked drivers/block/loop.c:424 [inline]
 loop_handle_cmd drivers/block/loop.c:1866 [inline]
 loop_process_work+0x8a4/0x10d0 drivers/block/loop.c:1901
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0000:ffffc90000107a38 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffff8beceec0 RCX: ffffffff86084265
RDX: 1ffffffff17d9ddd RSI: ffffc90000107b28 RDI: ffff888025fe3128
RBP: ffff888025fe3128 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000002be0 R12: ffffc90000107b28
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880d6cb2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000001caa6000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400