syzbot


KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter (5)

Status: auto-closed as invalid on 2022/06/02 15:56
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 299d, last: 273d
similar bugs (6):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter 10 973d 1096d 0/24 closed as invalid on 2020/06/18 14:24
upstream KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter (3) 10 828d 884d 0/24 auto-closed as invalid on 2020/11/24 16:04
upstream KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter (7) 6 46d 62d 0/24 auto-obsoleted due to no activity on 2023/01/17 06:15
upstream KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter (4) 14 358d 458d 0/24 auto-closed as invalid on 2022/03/09 00:14
upstream KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter (2) 2 935d 949d 0/24 auto-closed as invalid on 2020/08/09 00:56
upstream KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter (6) 1 193d 193d 0/24 auto-closed as invalid on 2022/08/21 13:12

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

read-write to 0xffff888237c1e0b4 of 1 bytes by task 0 on cpu 0:
 tick_nohz_idle_enter+0x6c/0xc0 kernel/time/tick-sched.c:1158
 do_idle+0x3d/0x250 kernel/sched/idle.c:277
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:400
 rest_init+0xed/0xf0 init/main.c:726
 arch_call_rest_init+0xa/0xb init/main.c:882
 start_kernel+0x5e4/0x669 init/main.c:1140
 secondary_startup_64_no_verify+0xc4/0xcb

read to 0xffff888237c1e0b4 of 1 bytes by task 8170 on cpu 1:
 get_cpu_idle_time_us+0x68/0x1d0
 get_idle_time fs/proc/stat.c:54 [inline]
 show_stat+0x97e/0xe60 fs/proc/stat.c:175
 seq_read_iter+0x2c3/0x8e0 fs/seq_file.c:230
 proc_reg_read_iter+0xd4/0x170 fs/proc/inode.c:296
 call_read_iter include/linux/fs.h:2044 [inline]
 io_iter_do_read fs/io_uring.c:3742 [inline]
 io_read fs/io_uring.c:3860 [inline]
 io_issue_sqe+0x1bd3/0x8690 fs/io_uring.c:7133
 __io_queue_sqe fs/io_uring.c:7502 [inline]
 io_queue_sqe fs/io_uring.c:7544 [inline]
 io_submit_sqe+0x65d/0x4250 fs/io_uring.c:7749
 io_submit_sqes+0x25e/0x7e0 fs/io_uring.c:7855
 __do_sys_io_uring_enter fs/io_uring.c:10800 [inline]
 __se_sys_io_uring_enter+0x2cb/0xc70 fs/io_uring.c:10726
 __x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:10726
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00 -> 0x05

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8170 Comm: syz-executor.2 Not tainted 5.18.0-rc4-syzkaller-00064-g8f4dd16603ce-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-upstream-kcsan-gce 2022/04/28 15:47 upstream 8f4dd16603ce e9076525 .config console log report info KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter
ci2-upstream-kcsan-gce 2022/04/02 22:27 upstream be2d3ecedd99 79a2a8fc .config console log report info KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter
* Struck through repros no longer work on HEAD.