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KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter (7)

Status: auto-obsoleted due to no activity on 2023/01/17 06:15
Subsystems: kernel
[Documentation on labels]
First crash: 512d, last: 496d
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter (5) kernel 2 723d 749d 0/26 auto-closed as invalid on 2022/06/02 15:56
upstream KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter kernel 10 1424d 1547d 0/26 closed as invalid on 2020/06/18 14:24
upstream KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter (3) kernel 10 1278d 1334d 0/26 auto-closed as invalid on 2020/11/24 16:04
upstream KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter (4) kernel 14 809d 909d 0/26 auto-closed as invalid on 2022/03/09 00:14
upstream KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter (2) kernel 2 1386d 1399d 0/26 auto-closed as invalid on 2020/08/09 00:56
upstream KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter (6) kernel 1 643d 643d 0/26 auto-closed as invalid on 2022/08/21 13:12

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

read-write to 0xffff888237d1e0bc of 1 bytes by task 0 on cpu 1:
 tick_nohz_idle_enter+0x6c/0xc0 kernel/time/tick-sched.c:1159
 do_idle+0x3d/0x250 kernel/sched/idle.c:277
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:400
 start_secondary+0x78/0x80 arch/x86/kernel/smpboot.c:262
 secondary_startup_64_no_verify+0xcf/0xdb

read to 0xffff888237d1e0bc of 1 bytes by task 7717 on cpu 0:
 get_cpu_idle_time_us+0x68/0x1d0
 get_idle_time fs/proc/stat.c:54 [inline]
 show_stat+0x99f/0xcd0 fs/proc/stat.c:175
 seq_read_iter+0x2c3/0x8e0 fs/seq_file.c:230
 proc_reg_read_iter+0xd4/0x170 fs/proc/inode.c:301
 call_read_iter include/linux/fs.h:2193 [inline]
 generic_file_splice_read+0xde/0x2b0 fs/splice.c:309
 do_splice_to fs/splice.c:793 [inline]
 splice_direct_to_actor+0x26c/0x620 fs/splice.c:865
 do_splice_direct+0xfb/0x180 fs/splice.c:974
 do_sendfile+0x3bf/0x910 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00 -> 0x05

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7717 Comm: syz-executor.1 Not tainted 6.1.0-rc8-syzkaller-00164-g4cee37b3a4e6-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
==================================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/12/11 20:57 upstream 4cee37b3a4e6 67be1ae7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter
2022/12/09 02:25 upstream f3e8416619ce 1034e5fa .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter
2022/12/08 16:27 upstream 479174d402bc 1034e5fa .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter
2022/12/08 07:39 upstream 479174d402bc d88f3abb .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter
2022/12/05 10:23 upstream 0ba09b173387 e080de16 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter
2022/11/25 19:18 upstream 08ad43d554ba 74a66371 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in get_cpu_idle_time_us / tick_nohz_idle_enter
* Struck through repros no longer work on HEAD.