syzbot


KCSAN: data-race in wq_worker_tick / wq_worker_tick

Status: moderation: reported on 2023/12/07 10:03
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+1f9c6a9361cf67ffc0d9@syzkaller.appspotmail.com
First crash: 888d, last: 14h47m

Sample crash report:
==================================================================
BUG: KCSAN: data-race in wq_worker_tick / wq_worker_tick

read-write to 0xffff8881000738b8 of 8 bytes by interrupt on cpu 0:
 wq_worker_tick+0x60/0x230 kernel/workqueue.c:1480
 sched_tick+0xd7/0x220 kernel/sched/core.c:5538
 update_process_times+0x15f/0x190 kernel/time/timer.c:2479
 tick_sched_handle kernel/time/tick-sched.c:298 [inline]
 tick_nohz_handler+0x276/0x3d0 kernel/time/tick-sched.c:319
 __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:1045 [inline]
 __sysvec_apic_timer_interrupt+0x5f/0x1d0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
 crng_make_state+0xf7/0x250 drivers/char/random.c:394
 _get_random_bytes+0x85/0x190 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:791 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
 nsim_dev_trap_report_work+0x482/0x630 drivers/net/netdevsim/dev.c:866
 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+0x149/0x290 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

read-write to 0xffff8881000738b8 of 8 bytes by interrupt on cpu 1:
 wq_worker_tick+0x60/0x230 kernel/workqueue.c:1480
 sched_tick+0xd7/0x220 kernel/sched/core.c:5538
 update_process_times+0x15f/0x190 kernel/time/timer.c:2479
 tick_sched_handle kernel/time/tick-sched.c:298 [inline]
 tick_nohz_handler+0x276/0x3d0 kernel/time/tick-sched.c:319
 __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:1045 [inline]
 __sysvec_apic_timer_interrupt+0x5f/0x1d0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
 crng_make_state+0xf7/0x250 drivers/char/random.c:394
 _get_random_bytes+0x85/0x190 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:791 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
 nsim_dev_trap_report_work+0x482/0x630 drivers/net/netdevsim/dev.c:866
 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+0x149/0x290 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

value changed: 0x00000000005dfe80 -> 0x00000000005e2590

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 12 Comm: kworker/u8:0 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound nsim_dev_trap_report_work
==================================================================

Crashes (535):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/03 04:25 upstream d61f1cc5db79 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/12/02 21:36 upstream 4a26e7032d7d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/12/01 23:17 upstream 1d18101a644e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/12/01 07:26 upstream 7d0a66e4bb90 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/12/01 01:12 upstream e69c7c175115 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/30 14:18 upstream 6bda50f4333f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/28 19:53 upstream e538109ac71d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/27 20:15 upstream 765e56e41a5a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/27 00:23 upstream 4941a17751c9 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/26 19:09 upstream 30f09200cc4a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/26 11:05 upstream 30f09200cc4a 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/25 20:52 upstream 8a2bcda5e139 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/25 14:46 upstream ac3fd01e4c1e 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/24 14:35 upstream ac3fd01e4c1e bf6fe8fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/23 09:36 upstream d13f3ac64efb 4fb8ef37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/22 23:47 upstream 89edd36fd801 4fb8ef37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/21 21:08 upstream 2eba5e05d9bc 4fb8ef37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/19 22:43 upstream 23cb64fb7625 26ee5237 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/17 09:21 upstream 6a23ae0a96a6 f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/16 21:53 upstream 7254a2b52279 f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/16 07:07 upstream f824272b6e3f f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/14 06:39 upstream 6da43bbeb691 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/13 20:51 upstream 2ccec5944606 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/12 18:47 upstream 24172e0d7990 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/12 11:53 upstream 24172e0d7990 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/06 04:32 upstream 1c353dc8d962 a6c9c731 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/05 08:38 upstream 17d85f33a83b a6c9c731 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/05 02:56 upstream 17d85f33a83b 686bf657 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/04 07:01 upstream 8bb886cb8f3a 686bf657 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/02 22:06 upstream 6146a0f1dfae 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/11/01 15:17 upstream ba36dd5ee6fd 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/10/31 09:37 upstream d127176862a9 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/10/30 04:53 upstream e53642b87a4f fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/10/27 18:17 upstream dcb6fa37fd7b fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/10/27 00:32 upstream dbfc6422a34d c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/10/26 12:15 upstream 72761a7e3122 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/10/26 00:10 upstream 566771afc7a8 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/10/24 12:05 upstream 6fab32bb6508 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/10/23 11:47 upstream 43e9ad0c55a3 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/10/23 01:55 upstream dd72c8fcf6d3 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/10/21 09:16 upstream 6548d364a3e8 9832ed61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/10/21 00:13 upstream 211ddde0823f d422939c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/10/19 01:17 upstream 1c64efcb083c 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/10/18 20:48 upstream f406055cb18c 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/10/16 06:01 upstream 7ea30958b305 19568248 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2025/10/15 17:03 upstream 1f4a222b0e33 19568248 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2023/12/01 12:41 upstream e8f60209d6cf f819d6f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
2023/11/28 23:33 upstream 18d46e76d7c2 1adfb6f6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in wq_worker_tick / wq_worker_tick
* Struck through repros no longer work on HEAD.