================================================================== BUG: KCSAN: data-race in wq_worker_tick / wq_worker_tick read-write to 0xffff8881000730b8 of 8 bytes by interrupt on cpu 0: wq_worker_tick+0x63/0x240 kernel/workqueue.c:1474 sched_tick+0x116/0x260 kernel/sched/core.c:5677 update_process_times+0x161/0x190 kernel/time/timer.c:2520 tick_sched_handle kernel/time/tick-sched.c:276 [inline] tick_nohz_handler+0x250/0x2d0 kernel/time/tick-sched.c:297 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x221/0x5f0 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x235/0x4a0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x5c/0x1d0 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x6e/0x80 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 crng_make_state+0xf9/0x260 arch/x86/include/asm/irqflags.h:-1 _get_random_bytes+0x87/0x190 drivers/char/random.c:406 get_random_bytes+0x1d/0x30 drivers/char/random.c:438 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:775 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x46b/0x630 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x4de/0xa20 kernel/workqueue.c:3319 worker_thread+0x52c/0x710 kernel/workqueue.c:3400 kthread+0x4b7/0x540 kernel/kthread.c:464 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read-write to 0xffff8881000730b8 of 8 bytes by interrupt on cpu 1: wq_worker_tick+0x63/0x240 kernel/workqueue.c:1474 sched_tick+0x116/0x260 kernel/sched/core.c:5677 update_process_times+0x161/0x190 kernel/time/timer.c:2520 tick_sched_handle kernel/time/tick-sched.c:276 [inline] tick_nohz_handler+0x250/0x2d0 kernel/time/tick-sched.c:297 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x221/0x5f0 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x235/0x4a0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x5c/0x1d0 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x6e/0x80 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 kcsan_setup_watchpoint+0x404/0x410 kernel/kcsan/core.c:705 skb_tail_pointer include/linux/skbuff.h:2656 [inline] skb_put+0x29/0x100 net/core/skbuff.c:2584 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:761 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x2fd/0x630 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x4de/0xa20 kernel/workqueue.c:3319 worker_thread+0x52c/0x710 kernel/workqueue.c:3400 kthread+0x4b7/0x540 kernel/kthread.c:464 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 value changed: 0x000000000003f7a0 -> 0x0000000000041eb0 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 41 Comm: kworker/u8:2 Not tainted 6.15.0-rc2-syzkaller-00042-g1a1d569a75f3 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound nsim_dev_trap_report_work ==================================================================