================================================================== BUG: KCSAN: data-race in wq_worker_tick / wq_worker_tick read-write to 0xffff88810107e4b8 of 8 bytes by interrupt on cpu 0: wq_worker_tick+0x60/0x230 kernel/workqueue.c:1480 sched_tick+0x11a/0x270 kernel/sched/core.c:5616 update_process_times+0x15f/0x190 kernel/time/timer.c:2478 tick_sched_handle kernel/time/tick-sched.c:276 [inline] tick_nohz_handler+0x249/0x2d0 kernel/time/tick-sched.c:297 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x20f/0x5a0 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x21a/0x460 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x5f/0x1d0 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 __sanitizer_cov_trace_pc+0x0/0x70 bpf_probe_read_user_str+0x19/0x70 kernel/trace/bpf_trace.c:220 bpf_prog_7f11bb5dfa26a882+0x43/0x49 bpf_dispatcher_nop_func include/linux/bpf.h:1350 [inline] __bpf_prog_run include/linux/filter.h:721 [inline] bpf_prog_run include/linux/filter.h:728 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline] bpf_trace_run2+0x107/0x1c0 kernel/trace/bpf_trace.c:2116 __do_trace_kfree include/trace/events/kmem.h:97 [inline] trace_kfree include/trace/events/kmem.h:97 [inline] kfree+0x351/0x400 mm/slub.c:6832 percpu_ref_exit+0xf3/0x110 lib/percpu-refcount.c:146 io_ring_ctx_free+0x24d/0x3a0 io_uring/io_uring.c:2869 io_ring_exit_work+0x529/0x560 io_uring/io_uring.c:3086 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3346 worker_thread+0x582/0x770 kernel/workqueue.c:3427 kthread+0x489/0x510 kernel/kthread.c:463 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read-write to 0xffff88810107e4b8 of 8 bytes by interrupt on cpu 1: wq_worker_tick+0x60/0x230 kernel/workqueue.c:1480 sched_tick+0x11a/0x270 kernel/sched/core.c:5616 update_process_times+0x15f/0x190 kernel/time/timer.c:2478 tick_sched_handle kernel/time/tick-sched.c:276 [inline] tick_nohz_handler+0x249/0x2d0 kernel/time/tick-sched.c:297 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x20f/0x5a0 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x21a/0x460 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x5f/0x1d0 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 strncpy_from_user+0x1eb/0x230 lib/strncpy_from_user.c:120 strncpy_from_user_nofault+0x68/0xf0 mm/maccess.c:192 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:214 [inline] ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:223 [inline] bpf_probe_read_user_str+0x2a/0x70 kernel/trace/bpf_trace.c:220 bpf_prog_7f11bb5dfa26a882+0x43/0x49 bpf_dispatcher_nop_func include/linux/bpf.h:1350 [inline] __bpf_prog_run include/linux/filter.h:721 [inline] bpf_prog_run include/linux/filter.h:728 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline] bpf_trace_run2+0x107/0x1c0 kernel/trace/bpf_trace.c:2116 __do_trace_kfree include/trace/events/kmem.h:97 [inline] trace_kfree include/trace/events/kmem.h:97 [inline] kfree+0x351/0x400 mm/slub.c:6832 io_ring_ctx_free+0x327/0x3a0 io_uring/io_uring.c:2880 io_ring_exit_work+0x529/0x560 io_uring/io_uring.c:3086 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3346 worker_thread+0x582/0x770 kernel/workqueue.c:3427 kthread+0x489/0x510 kernel/kthread.c:463 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 value changed: 0x0000000000077a10 -> 0x000000000007a120 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 17490 Comm: kworker/u8:56 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: iou_exit io_ring_exit_work ==================================================================