------------[ cut here ]------------
WARNING: CPU: 1 PID: 2434 at kernel/kthread.c:819 queuing_blocked kernel/kthread.c:819 [inline]
WARNING: CPU: 1 PID: 2434 at kernel/kthread.c:819 kthread_queue_work+0x16d/0x1b0 kernel/kthread.c:866
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 2434 Comm: kworker/1:1H Not tainted 5.8.0-rc4-next-20200708-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: kblockd blk_mq_run_work_fn
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:231
 __warn.cold+0x20/0x45 kernel/panic.c:600
 report_bug+0x1bd/0x210 lib/bug.c:198
 handle_bug+0x38/0x90 arch/x86/kernel/traps.c:234
 exc_invalid_op+0x13/0x40 arch/x86/kernel/traps.c:254
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:542
RIP: 0010:queuing_blocked kernel/kthread.c:819 [inline]
RIP: 0010:kthread_queue_work+0x16d/0x1b0 kernel/kthread.c:866
Code: 0f 85 72 ff ff ff e8 62 49 26 00 48 8d 55 48 4c 89 e6 48 89 ef e8 63 ec ff ff 41 bc 01 00 00 00 e9 56 ff ff ff e8 43 49 26 00 <0f> 0b 45 31 e4 e9 47 ff ff ff 48 c7 c7 f4 61 af 8a e8 dd fd 65 00
RSP: 0018:ffffc9000843f8e8 EFLAGS: 00010093
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff814db478
RDX: ffff8880a0dbe2c0 RSI: ffffffff814db4ed RDI: ffff8880a15d49c0
RBP: ffff8880a15d4958 R08: 0000000000000001 R09: 0000000000000003
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a1696328
R13: 0000000000000286 R14: ffff8880a15d4960 R15: dffffc0000000000
 loop_queue_rq+0x428/0x590 drivers/block/loop.c:2027
 blk_mq_dispatch_rq_list+0x2e0/0x1e40 block/blk-mq.c:1389
 __blk_mq_do_dispatch_sched+0x3bc/0x870 block/blk-mq-sched.c:194
 blk_mq_do_dispatch_sched block/blk-mq-sched.c:207 [inline]
 __blk_mq_sched_dispatch_requests+0x394/0x490 block/blk-mq-sched.c:323
 blk_mq_sched_dispatch_requests+0xfb/0x180 block/blk-mq-sched.c:349
 __blk_mq_run_hw_queue+0x13a/0x2d0 block/blk-mq.c:1529
 blk_mq_run_work_fn+0x55/0x70 block/blk-mq.c:1807
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Kernel Offset: disabled
Rebooting in 86400 seconds..