syzbot


KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter (4)

Status: auto-closed as invalid on 2022/03/17 13:24
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 401d, last: 298d
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 764d 729d 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 (3) 1 458d 458d 0/24 auto-closed as invalid on 2021/10/09 06:41
upstream KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter 9 920d 1038d 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 201d 201d 0/24 auto-closed as invalid on 2022/06/22 15:45

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

write to 0xffff888237d1e0b4 of 1 bytes by task 0 on cpu 1:
 tick_nohz_idle_enter+0x72/0xc0 kernel/time/tick-sched.c:1113
 do_idle+0x3d/0x250 kernel/sched/idle.c:280
 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 28059 on cpu 0:
 get_cpu_iowait_time_us+0x6b/0x1f0
 get_iowait_time fs/proc/stat.c:70 [inline]
 show_stat+0x91f/0xdd0 fs/proc/stat.c:176
 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+0xb2e/0x98d0 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:10154 [inline]
 __se_sys_io_uring_enter+0x212/0xb00 fs/io_uring.c:10096
 __x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:10096
 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: 0x00 -> 0x05

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 28059 Comm: syz-executor.2 Not tainted 5.17.0-rc3-syzkaller-00043-gf4bc5bbb5fef-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (12):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/02/10 13:16 upstream f4bc5bbb5fef 0b33604d .config log report info KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter
ci2-upstream-kcsan-gce 2022/01/30 05:17 upstream f8c7e4ede46f 495e00c5 .config log report info KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter
ci2-upstream-kcsan-gce 2022/01/25 18:12 upstream 49d766f3a0e4 2cbffd88 .config log report info KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter
ci2-upstream-kcsan-gce 2022/01/16 09:00 upstream d0a231f01e5b 723cfaf0 .config log report info KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter
ci2-upstream-kcsan-gce 2022/01/07 16:28 upstream ddec8ed2d490 2ca0d385 .config log report info KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter
ci2-upstream-kcsan-gce 2022/01/03 16:54 upstream c9e6606c7fe9 4a3f34f2 .config log report info KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter
ci2-upstream-kcsan-gce 2021/12/20 21:29 upstream 86085fe79e3c 62bd192b .config log report info KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter
ci2-upstream-kcsan-gce 2021/12/12 21:18 upstream 90d9fbc16b69 49ca1f59 .config log report info KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter
ci2-upstream-kcsan-gce 2021/12/08 02:38 upstream 2a987e65025e 0230ba3e .config log report info KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter
ci2-upstream-kcsan-gce 2021/11/10 06:08 upstream cb690f5238d7 55fa030c .config log report info KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter
ci2-upstream-kcsan-gce 2021/11/05 10:06 upstream d4439a1189f9 4c1be0be .config log report info KCSAN: data-race in get_cpu_iowait_time_us / tick_nohz_idle_enter
ci2-upstream-kcsan-gce 2021/10/31 11:08 upstream 119c85055d86 098b5d53 .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.