==================================================================
BUG: KCSAN: data-race in io_flush_timeouts / io_issue_sqe

read-write to 0xffff88811bc57210 of 4 bytes by task 5330 on cpu 0:
 io_get_cqe_overflow io_uring/io_uring.h:256 [inline]
 io_get_cqe io_uring/io_uring.h:271 [inline]
 io_fill_cqe_req io_uring/io_uring.h:293 [inline]
 io_req_complete_post io_uring/io_uring.c:986 [inline]
 io_issue_sqe+0x1f9/0xa70 io_uring/io_uring.c:1822
 io_wq_submit_work+0x3f7/0x5f0 io_uring/io_uring.c:1928
 io_worker_handle_work+0x44d/0x9b0 io_uring/io-wq.c:650
 io_wq_worker+0x22d/0x860 io_uring/io-wq.c:704
 ret_from_fork+0x148/0x280 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

read to 0xffff88811bc57210 of 4 bytes by task 5331 on cpu 1:
 io_flush_timeouts+0x62/0x1e0 io_uring/timeout.c:133
 __io_commit_cqring_flush+0xeb/0x100 io_uring/io_uring.c:544
 io_commit_cqring_flush io_uring/io_uring.h:531 [inline]
 io_cq_unlock_post io_uring/io_uring.c:580 [inline]
 io_req_complete_post io_uring/io_uring.c:987 [inline]
 io_issue_sqe+0x8ab/0xa70 io_uring/io_uring.c:1822
 io_wq_submit_work+0x3f7/0x5f0 io_uring/io_uring.c:1928
 io_worker_handle_work+0x44d/0x9b0 io_uring/io-wq.c:650
 io_wq_worker+0x22d/0x860 io_uring/io-wq.c:704
 ret_from_fork+0x148/0x280 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

value changed: 0x00000221 -> 0x00000222

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 5331 Comm: iou-wrk-5316 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
==================================================================