==================================================================
BUG: KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter

write to 0xffff888237d1debc 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+0xb1/0xbb

read to 0xffff888237d1debc of 1 bytes by task 16730 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:2155 [inline]
 io_iter_do_read fs/io_uring.c:3462 [inline]
 io_read fs/io_uring.c:3519 [inline]
 io_issue_sqe+0xbf6/0x5680 fs/io_uring.c:6628
 __io_queue_sqe+0x20/0x450 fs/io_uring.c:6978
 io_queue_sqe fs/io_uring.c:7020 [inline]
 io_submit_sqe+0x77a/0x47d3 fs/io_uring.c:7223
 io_submit_sqes+0x25d/0x670 fs/io_uring.c:7329
 __do_sys_io_uring_enter fs/io_uring.c:10043 [inline]
 __se_sys_io_uring_enter+0x212/0xb00 fs/io_uring.c:9985
 __x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:9985
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 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: 16730 Comm: syz-executor.0 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
CPU: 0 PID: 16730 Comm: syz-executor.0 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd6/0x122 lib/dump_stack.c:106
 dump_stack+0x11/0x1b lib/dump_stack.c:113
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail+0x23c/0x250 lib/fault-inject.c:146
 should_fail_usercopy+0x16/0x20 lib/fault-inject-usercopy.c:37
 copyout lib/iov_iter.c:153 [inline]
 _copy_to_iter+0x131/0xbe0 lib/iov_iter.c:667
 copy_to_iter include/linux/uio.h:155 [inline]
 seq_read_iter+0x7f2/0x930 fs/seq_file.c:281
 proc_reg_read_iter+0xd6/0x170 fs/proc/inode.c:296
 call_read_iter include/linux/fs.h:2155 [inline]
 io_iter_do_read fs/io_uring.c:3462 [inline]
 io_read fs/io_uring.c:3519 [inline]
 io_issue_sqe+0xbf6/0x5680 fs/io_uring.c:6628
 __io_queue_sqe+0x20/0x450 fs/io_uring.c:6978
 io_queue_sqe fs/io_uring.c:7020 [inline]
 io_submit_sqe+0x77a/0x47d3 fs/io_uring.c:7223
 io_submit_sqes+0x25d/0x670 fs/io_uring.c:7329
 __do_sys_io_uring_enter fs/io_uring.c:10043 [inline]
 __se_sys_io_uring_enter+0x212/0xb00 fs/io_uring.c:9985
 __x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:9985
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f6179b4cae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f61778c3188 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007f6179c5ff60 RCX: 00007f6179b4cae9
RDX: 0000000000000000 RSI: 00000000000002ff RDI: 0000000000000006
RBP: 00007f61778c31d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 00007ffdd913e7bf R14: 00007f61778c3300 R15: 0000000000022000
 </TASK>