syzbot


KCSAN: data-race in print_cpu / tick_nohz_idle_enter (10)

Status: moderation: reported on 2024/05/11 22:38
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+dbec1d508021c2bd1bfd@syzkaller.appspotmail.com
First crash: 152d, last: 11d
Similar bugs (9)
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 407d 407d 0/28 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 792d 801d 0/28 auto-closed as invalid on 2022/09/15 04:11
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (8) kernel 1 233d 233d 0/28 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 840d 840d 0/28 auto-closed as invalid on 2022/07/29 11:15
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (5) kernel 1 634d 634d 0/28 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 549d 549d 0/28 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 1114d 1114d 0/28 auto-closed as invalid on 2021/10/28 01:37
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (2) kernel 2 1045d 1069d 0/28 auto-closed as invalid on 2022/01/05 10:03
upstream KCSAN: data-race in print_cpu / tick_nohz_idle_enter (9) kernel 1 197d 197d 0/28 auto-obsoleted due to no activity on 2024/05/02 11:27

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

read-write to 0xffff888237c204b0 of 8 bytes by task 0 on cpu 0:
 tick_sched_flag_set kernel/time/tick-sched.c:194 [inline]
 tick_nohz_idle_enter+0x59/0xe0 kernel/time/tick-sched.c:1262
 do_idle+0x3d/0x230 kernel/sched/idle.c:271
 cpu_startup_entry+0x25/0x30 kernel/sched/idle.c:424
 rest_init+0xef/0xf0 init/main.c:747
 start_kernel+0x586/0x5e0 init/main.c:1105
 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507
 x86_64_start_kernel+0x9a/0xa0 arch/x86/kernel/head64.c:488
 common_startup_64+0x12c/0x137

read to 0xffff888237c204b0 of 8 bytes by task 6817 on cpu 1:
 print_cpu+0x404/0x670 kernel/time/timer_list.c:156
 timer_list_show+0x115/0x180 kernel/time/timer_list.c:295
 seq_read_iter+0x655/0x930 fs/seq_file.c:272
 proc_reg_read_iter+0x118/0x190 fs/proc/inode.c:299
 copy_splice_read+0x3a0/0x5d0 fs/splice.c:365
 do_splice_read fs/splice.c:985 [inline]
 splice_direct_to_actor+0x269/0x670 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x39b/0x970 fs/read_write.c:1388
 __do_sys_sendfile64 fs/read_write.c:1455 [inline]
 __se_sys_sendfile64 fs/read_write.c:1441 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1441
 x64_sys_call+0xed5/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000038 -> 0x000000000000003d

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 6817 Comm: syz.2.1113 Tainted: G        W          6.12.0-rc1-syzkaller #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================

Crashes (17):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/30 16:39 upstream 9852d85ec9d4 bbd4e0a4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/09/27 09:20 upstream 075dbe9f6e3c 9314348a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/09/24 22:53 upstream abf2050f51fd 5643e0e9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/09/03 15:16 upstream 67784a74e258 326f9c5a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/09/01 02:43 upstream e8784b0aef62 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/08/27 14:50 upstream 3e9bff3bbe13 9aee4e0b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/07/27 20:15 upstream 3a7e02c040b1 46eb10b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/07/17 00:07 upstream d67978318827 b66b37bd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/06/26 13:14 upstream 55027e689933 c6d33a01 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/06/22 07:23 upstream 66cc544fd75c edc5149a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/06/11 19:47 upstream 83a7eefedc9b 4d75f4f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/06/08 23:40 upstream dc772f8237f9 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/06/01 04:37 upstream d8ec19857b09 3113787f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/05/29 09:55 upstream e0cce98fe279 34889ee3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/05/25 08:28 upstream 56fb6f92854f a10a183e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/05/25 04:52 upstream 02c438bbfffe a10a183e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_enter
2024/05/11 22:37 upstream cf87f46fd34d 9026e142 .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.