syzbot


KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter (3)

Status: auto-closed as invalid on 2021/10/09 06:41
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 459d, last: 459d
similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter (2) 8 766d 730d 0/24 auto-closed as invalid on 2020/12/21 11:40
upstream KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter 9 921d 1040d 0/24 closed as invalid on 2020/06/18 14:24
upstream KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter (5) 1 203d 203d 0/24 auto-closed as invalid on 2022/06/22 15:45
upstream KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter (4) 12 300d 402d 0/24 auto-closed as invalid on 2022/03/17 13:24

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

write to 0xffff888237d19d34 of 1 bytes by task 0 on cpu 1:
 tick_nohz_idle_enter+0x5e/0xb0 kernel/time/tick-sched.c:1113
 do_idle+0x3d/0x240 kernel/sched/idle.c:280
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:403
 secondary_startup_64_no_verify+0xb0/0xbb

read to 0xffff888237d19d34 of 1 bytes by task 26955 on cpu 0:
 get_cpu_iowait_time_us+0x6b/0x1f0 kernel/time/tick-sched.c:724
 get_iowait_time fs/proc/stat.c:70 [inline]
 show_stat+0x354/0xdb0 fs/proc/stat.c:135
 seq_read_iter+0x2e1/0x930 fs/seq_file.c:230
 proc_reg_read_iter+0xd6/0x170 fs/proc/inode.c:296
 call_read_iter include/linux/fs.h:2157 [inline]
 aio_read+0x1c1/0x280 fs/aio.c:1538
 __io_submit_one fs/aio.c:1835 [inline]
 io_submit_one+0x7fb/0x1350 fs/aio.c:1880
 __do_sys_io_submit fs/aio.c:1939 [inline]
 __se_sys_io_submit+0xf5/0x260 fs/aio.c:1909
 __x64_sys_io_submit+0x3f/0x50 fs/aio.c:1909
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00 -> 0x05

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 26955 Comm: syz-executor.0 Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/09/04 06:38 upstream a9c9a6f741cd d236a457 .config log report info KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter
* Struck through repros no longer work on HEAD.