syzbot


KCSAN: data-race in print_cpu / tick_nohz_idle_enter

Status: auto-closed as invalid on 2021/10/28 01:37
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 438d, last: 438d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (4) 3 116d 125d 0/24 auto-closed as invalid on 2022/09/15 04:11
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (3) 1 164d 164d 0/24 auto-closed as invalid on 2022/07/29 11:15
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (2) 2 369d 393d 0/24 auto-closed as invalid on 2022/01/05 10:03

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

write to 0xffff888237c19d68 of 8 bytes by task 0 on cpu 0:
 tick_nohz_start_idle kernel/time/tick-sched.c:656 [inline]
 tick_nohz_idle_enter+0x76/0xb0 kernel/time/tick-sched.c:1114
 do_idle+0x3d/0x250 kernel/sched/idle.c:280
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:403
 rest_init+0xee/0x100 init/main.c:733
 arch_call_rest_init+0xa/0xb
 start_kernel+0x5e4/0x669 init/main.c:1141
 secondary_startup_64_no_verify+0xb1/0xbb

read to 0xffff888237c19d68 of 8 bytes by task 9089 on cpu 1:
 print_cpu+0x4fe/0x690 kernel/time/timer_list.c:158
 timer_list_show+0x114/0x180 kernel/time/timer_list.c:291
 traverse+0x150/0x3b0 fs/seq_file.c:111
 seq_read_iter+0x87b/0x930 fs/seq_file.c:195
 proc_reg_read_iter+0xfc/0x170 fs/proc/inode.c:300
 call_read_iter include/linux/fs.h:2157 [inline]
 aio_read+0x1d8/0x290 fs/aio.c:1538
 io_submit_one+0x83b/0x13b0 fs/aio.c:1880
 __do_sys_io_submit fs/aio.c:1939 [inline]
 __se_sys_io_submit+0x105/0x270 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+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x000000ab1b156ecd -> 0x000000ab1b15c5e7

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 9089 Comm: syz-executor.1 Tainted: G        W         5.15.0-rc2-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 2021/09/23 01:32 upstream cf1d2c3e7e2f 8cac236e .config log report info KCSAN: data-race in print_cpu / tick_nohz_idle_enter
* Struck through repros no longer work on HEAD.