syzbot


KCSAN: data-race in print_cpu / tick_nohz_idle_enter (8)

Status: auto-obsoleted due to no activity on 2024/03/27 09:49
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+e19f5c95e492efe7c2ea@syzkaller.appspotmail.com
First crash: 52d, last: 52d
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (7) kernel 1 225d 225d 0/26 auto-obsoleted due to no activity on 2023/10/05 16:08
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (4) kernel 3 611d 619d 0/26 auto-closed as invalid on 2022/09/15 04:11
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (3) kernel 1 659d 659d 0/26 auto-closed as invalid on 2022/07/29 11:15
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (5) kernel 1 452d 452d 0/26 auto-obsoleted due to no activity on 2023/02/27 15:47
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (6) kernel 1 368d 368d 0/26 auto-obsoleted due to no activity on 2023/05/16 12:25
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter kernel 1 933d 933d 0/26 auto-closed as invalid on 2021/10/28 01:37
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (2) kernel 2 864d 888d 0/26 auto-closed as invalid on 2022/01/05 10:03
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (9) kernel 1 16d 16d 0/26 moderation: reported on 2024/03/28 11:27

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

write to 0xffff888237d1f668 of 8 bytes by task 0 on cpu 1:
 tick_nohz_start_idle kernel/time/tick-sched.c:687 [inline]
 tick_nohz_idle_enter+0x85/0xd0 kernel/time/tick-sched.c:1175
 do_idle+0x3c/0x230 kernel/sched/idle.c:256
 cpu_startup_entry+0x24/0x30 kernel/sched/idle.c:410
 start_secondary+0x82/0x90 arch/x86/kernel/smpboot.c:336
 secondary_startup_64_no_verify+0x15f/0x16b

read to 0xffff888237d1f668 of 8 bytes by task 31776 on cpu 0:
 print_cpu+0x4c4/0x640 kernel/time/timer_list.c:158
 timer_list_show+0x115/0x180 kernel/time/timer_list.c:291
 seq_read_iter+0x612/0x8f0 fs/seq_file.c:272
 proc_reg_read_iter+0x114/0x180 fs/proc/inode.c:302
 call_read_iter include/linux/fs.h:2079 [inline]
 copy_splice_read+0x39f/0x5d0 fs/splice.c:365
 do_splice_read fs/splice.c:985 [inline]
 splice_direct_to_actor+0x268/0x660 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x3b9/0x960 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64 fs/read_write.c:1348 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000008c29236342 -> 0x0000008c2925a868

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 31776 Comm: syz-executor.1 Not tainted 6.8.0-rc5-syzkaller-00002-gfca7526b7d89 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/02/21 09:48 upstream fca7526b7d89 3af7dd65 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
* Struck through repros no longer work on HEAD.