syzbot


KCSAN: data-race in print_cpu / tick_nohz_idle_enter (9)

Status: moderation: reported on 2024/03/28 11:27
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+0152ac61fac5c14c46d0@syzkaller.appspotmail.com
First crash: 19d, last: 19d
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 229d 229d 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 614d 623d 0/26 auto-closed as invalid on 2022/09/15 04:11
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (8) kernel 1 55d 55d 0/26 auto-obsoleted due to no activity on 2024/03/27 09:49
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (3) kernel 1 662d 662d 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 456d 456d 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 371d 371d 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 936d 936d 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 867d 891d 0/26 auto-closed as invalid on 2022/01/05 10:03

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

read-write to 0xffff888237d204f8 of 8 bytes by task 0 on cpu 1:
 tick_sched_flag_set kernel/time/tick-sched.c:193 [inline]
 tick_nohz_idle_enter+0x59/0xe0 kernel/time/tick-sched.c:1253
 do_idle+0x3d/0x230 kernel/sched/idle.c:277
 cpu_startup_entry+0x25/0x30 kernel/sched/idle.c:430
 start_secondary+0x94/0xa0 arch/x86/kernel/smpboot.c:313
 common_startup_64+0x12c/0x137

read to 0xffff888237d204f8 of 8 bytes by task 16016 on cpu 0:
 print_cpu+0x404/0x670 kernel/time/timer_list.c:156
 timer_list_show+0x115/0x180 kernel/time/timer_list.c:295
 seq_read_iter+0x2d7/0x940 fs/seq_file.c:230
 proc_reg_read_iter+0x11e/0x190 fs/proc/inode.c:299
 call_read_iter include/linux/fs.h:2102 [inline]
 copy_splice_read+0x3a4/0x5d0 fs/splice.c:365
 do_splice_read fs/splice.c:985 [inline]
 splice_direct_to_actor+0x26c/0x670 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x3b9/0x970 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_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

value changed: 0x0000000000000030 -> 0x0000000000000035

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 16016 Comm: syz-executor.4 Not tainted 6.9.0-rc1-syzkaller-00061-g8d025e2092e2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/28 11:27 upstream 8d025e2092e2 120789fd .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.