KCSAN: data-race in get_cpu_idle_time_us / update_ts_time_stats

Status: closed as invalid on 2020/06/18 14:24
Subsystems: kernel
[Documentation on labels]
First crash: 2405d, last: 2262d

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

write to 0xffff88812c020350 of 8 bytes by task 0 on cpu 0:
 update_ts_time_stats+0xe5/0x130 kernel/time/tick-sched.c:545
 tick_nohz_stop_idle kernel/time/tick-sched.c:556 [inline]
 tick_nohz_irq_enter kernel/time/tick-sched.c:1276 [inline]
 tick_irq_enter+0x173/0x1b0 kernel/time/tick-sched.c:1295
 irq_enter+0x49/0x50 kernel/softirq.c:354
 entering_irq arch/x86/include/asm/apic.h:527 [inline]
 entering_ack_irq arch/x86/include/asm/apic.h:533 [inline]
 smp_apic_timer_interrupt+0x52/0x270 arch/x86/kernel/apic/apic.c:1136
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60
 arch_safe_halt arch/x86/include/asm/paravirt.h:144 [inline]
 default_idle+0x21/0x170 arch/x86/kernel/process.c:697
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x1b7/0x290 kernel/sched/idle.c:269
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:361
 rest_init+0xe4/0xeb init/main.c:667
 arch_call_rest_init+0x13/0x2b
 start_kernel+0x7fe/0x823 init/main.c:1005
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242

read to 0xffff88812c020350 of 8 bytes by task 10720 on cpu 1:
 get_cpu_idle_time_us+0x153/0x170 kernel/time/tick-sched.c:599
 get_idle_time.isra.0+0x65/0x90 fs/proc/stat.c:53
 show_stat+0x61d/0xa50 fs/proc/stat.c:172
 seq_read+0x2ef/0x940 fs/seq_file.c:206
 pde_read fs/proc/inode.c:292 [inline]
 proc_reg_read+0xb3/0x1b0 fs/proc/inode.c:302
 do_loop_readv_writev fs/read_write.c:715 [inline]
 do_loop_readv_writev fs/read_write.c:702 [inline]
 do_iter_read+0x33f/0x3a0 fs/read_write.c:936
 vfs_readv+0x9c/0xf0 fs/read_write.c:1054
 do_preadv+0x129/0x1c0 fs/read_write.c:1146
 __do_sys_preadv fs/read_write.c:1196 [inline]
 __se_sys_preadv fs/read_write.c:1191 [inline]
 __x64_sys_preadv+0x5e/0x80 fs/read_write.c:1191
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10720 Comm: syz-executor.2 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (18):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/06 17:57 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 e6b89e4e .config console log report ci2-upstream-kcsan-gce
2020/05/29 10:34 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 d19ed305 .config console log report ci2-upstream-kcsan-gce
2020/04/22 00:12 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2e44d63e .config console log report ci2-upstream-kcsan-gce
2020/04/21 12:38 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 f20434a8 .config console log report ci2-upstream-kcsan-gce
2020/04/17 17:47 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 18397578 .config console log report ci2-upstream-kcsan-gce
2020/04/15 16:52 https://github.com/google/ktsan.git kcsan 40959e34d670 3f3c5574 .config console log report ci2-upstream-kcsan-gce
2020/04/08 16:12 https://github.com/google/ktsan.git kcsan 40959e34d670 db9bcd4b .config console log report ci2-upstream-kcsan-gce
2020/03/26 22:43 https://github.com/google/ktsan.git kcsan 40959e34d670 6d25c5a0 .config console log report ci2-upstream-kcsan-gce
2020/03/18 14:12 https://github.com/google/ktsan.git kcsan 941e0d917bbf 0a96a13c .config console log report ci2-upstream-kcsan-gce
2020/03/08 15:14 https://github.com/google/ktsan.git kcsan 941e0d917bbf 2e9971bb .config console log report ci2-upstream-kcsan-gce
2020/02/22 02:45 https://github.com/google/ktsan.git kcsan 766d004d1b85 2ffa6679 .config console log report ci2-upstream-kcsan-gce
2020/02/20 15:32 https://github.com/google/ktsan.git kcsan b12d66a6c34f 81230308 .config console log report ci2-upstream-kcsan-gce
2020/02/17 23:02 https://github.com/google/ktsan.git kcsan b12d66a6c34f 72bfa6f2 .config console log report ci2-upstream-kcsan-gce
2020/02/06 02:57 https://github.com/google/ktsan.git kcsan 245a43005292 662cf49a .config console log report ci2-upstream-kcsan-gce
2020/02/06 02:50 https://github.com/google/ktsan.git kcsan 245a43005292 662cf49a .config console log report ci2-upstream-kcsan-gce
2020/01/30 01:31 https://github.com/google/ktsan.git kcsan 245a43005292 5ed23f9a .config console log report ci2-upstream-kcsan-gce
2020/01/27 22:40 https://github.com/google/ktsan.git kcsan 245a43005292 56cd6c9b .config console log report ci2-upstream-kcsan-gce
2020/01/16 01:58 https://github.com/google/ktsan.git kcsan 245a43005292 f9b69507 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.