=====================================================
BUG: KMSAN: uninit-value in io_req_caches_free+0x2e6/0x640 fs/io_uring.c:9314
 io_req_caches_free+0x2e6/0x640 fs/io_uring.c:9314
 io_ring_exit_work+0x242/0xce2 fs/io_uring.c:9496
 process_one_work+0xdb9/0x1820 kernel/workqueue.c:2298
 worker_thread+0x10bc/0x21f0 kernel/workqueue.c:2445
 kthread+0x721/0x850 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

Uninit was stored to memory at:
 wq_stack_extract fs/io-wq.h:129 [inline]
 io_req_caches_free+0x300/0x640 fs/io_uring.c:9318
 io_ring_exit_work+0x242/0xce2 fs/io_uring.c:9496
 process_one_work+0xdb9/0x1820 kernel/workqueue.c:2298
 worker_thread+0x10bc/0x21f0 kernel/workqueue.c:2445
 kthread+0x721/0x850 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

Uninit was stored to memory at:
 wq_list_add_head fs/io-wq.h:71 [inline]
 io_req_complete_post+0x1782/0x1f00 fs/io_uring.c:1913
 io_req_task_timeout+0x138/0x190 fs/io_uring.c:5970
 tctx_task_work+0x71c/0xd50 fs/io_uring.c:2245
 task_work_run+0x154/0x290 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0x1332/0x4430 kernel/exit.c:834
 do_group_exit+0x21b/0x450 kernel/exit.c:931
 get_signal+0x2720/0x2ba0 kernel/signal.c:2852
 arch_do_signal_or_restart+0x9d/0xdd0 arch/x86/kernel/signal.c:868
 handle_signal_work kernel/entry/common.c:149 [inline]
 exit_to_user_mode_loop+0x1f6/0x490 kernel/entry/common.c:173
 exit_to_user_mode_prepare kernel/entry/common.c:208 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x7e/0xc0 kernel/entry/common.c:302
 do_syscall_64+0x60/0xd0 arch/x86/entry/common.c:88
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Uninit was stored to memory at:
 wq_list_add_head fs/io-wq.h:74 [inline]
 io_req_complete_post+0x17a1/0x1f00 fs/io_uring.c:1913
 io_req_task_timeout+0x138/0x190 fs/io_uring.c:5970
 tctx_task_work+0x71c/0xd50 fs/io_uring.c:2245
 task_work_run+0x154/0x290 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0x1332/0x4430 kernel/exit.c:834
 do_group_exit+0x21b/0x450 kernel/exit.c:931
 get_signal+0x2720/0x2ba0 kernel/signal.c:2852
 arch_do_signal_or_restart+0x9d/0xdd0 arch/x86/kernel/signal.c:868
 handle_signal_work kernel/entry/common.c:149 [inline]
 exit_to_user_mode_loop+0x1f6/0x490 kernel/entry/common.c:173
 exit_to_user_mode_prepare kernel/entry/common.c:208 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x7e/0xc0 kernel/entry/common.c:302
 do_syscall_64+0x60/0xd0 arch/x86/entry/common.c:88
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Uninit was created at:
 slab_post_alloc_hook mm/slab.h:524 [inline]
 kmem_cache_alloc_bulk+0xec5/0x1560 mm/slub.c:3747
 __io_alloc_req_refill+0x482/0x867 fs/io_uring.c:2015
 io_alloc_req_refill fs/io_uring.c:2041 [inline]
 io_submit_sqes+0x88c/0x1040 fs/io_uring.c:7356
 __do_sys_io_uring_enter fs/io_uring.c:10072 [inline]
 __se_sys_io_uring_enter+0x62f/0x23a0 fs/io_uring.c:10014
 __x64_sys_io_uring_enter+0x19d/0x200 fs/io_uring.c:10014
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x44/0xae

CPU: 0 PID: 27384 Comm: kworker/u4:9 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound io_ring_exit_work
=====================================================