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KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_got_tick

Status: auto-closed as invalid on 2022/04/21 10:19
Subsystems: kernel
[Documentation on labels]
First crash: 770d, last: 770d

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

write to 0xffff888237d1e0b4 of 1 bytes by task 0 on cpu 1:
 tick_nohz_idle_got_tick+0x67/0x80 kernel/time/tick-sched.c:1145
 menu_reflect+0x58/0x80 drivers/cpuidle/governors/menu.c:442
 cpuidle_reflect+0x52/0x60 drivers/cpuidle/cpuidle.c:368
 cpuidle_idle_call kernel/sched/idle.c:243 [inline]
 do_idle+0x1cc/0x250 kernel/sched/idle.c:306
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:403
 secondary_startup_64_no_verify+0xc4/0xcb

read to 0xffff888237d1e0b4 of 1 bytes by task 6342 on cpu 0:
 get_cpu_idle_time_us+0x6b/0x1f0
 get_idle_time fs/proc/stat.c:54 [inline]
 show_stat+0x8bf/0xdd0 fs/proc/stat.c:175
 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:2068 [inline]
 io_iter_do_read fs/io_uring.c:3611 [inline]
 io_read fs/io_uring.c:3668 [inline]
 io_issue_sqe+0xb34/0x9610 fs/io_uring.c:6751
 __io_queue_sqe+0x20/0x6a0 fs/io_uring.c:7098
 io_queue_sqe+0x46/0x550 fs/io_uring.c:7140
 io_submit_sqe+0x796/0x4b34 fs/io_uring.c:7348
 io_submit_sqes+0x25f/0x560 fs/io_uring.c:7454
 __do_sys_io_uring_enter fs/io_uring.c:10162 [inline]
 __se_sys_io_uring_enter+0x212/0xb00 fs/io_uring.c:10104
 __x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:10104
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x19 -> 0x08

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 6342 Comm: syz-executor.2 Not tainted 5.17.0-rc8-syzkaller-00003-g56e337f2cf13-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/03/17 10:10 upstream 56e337f2cf13 dfa9a8ed .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_got_tick
* Struck through repros no longer work on HEAD.