loop4: detected capacity change from 0 to 512
EXT4-fs (loop4): VFS: Can't find ext4 filesystem
mmap: syz-executor.2 (4059) uses deprecated remap_file_pages() syscall. See Documentation/vm/remap_file_pages.rst.
=============================
WARNING: suspicious RCU usage
5.17.0-rc3-next-20220207 #1 Not tainted
-----------------------------
fs/io_uring.c:9411 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
2 locks held by kworker/u4:7/345:
 #0: ffff888007861138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x915/0x16a0
 #1: ffff88803ed9fdb0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x949/0x16a0

stack backtrace:
CPU: 1 PID: 345 Comm: kworker/u4:7 Not tainted 5.17.0-rc3-next-20220207 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Workqueue: events_unbound io_ring_exit_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x8b/0xb3
 io_eventfd_unregister+0xee/0x110
 io_ring_exit_work+0x77d/0xbec
 process_one_work+0xa1c/0x16a0
 worker_thread+0x637/0x1260
 kthread+0x2f0/0x3a0
 ret_from_fork+0x22/0x30
 </TASK>