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KCSAN: data-race in print_cpu / tick_nohz_idle_exit

Status: auto-obsoleted due to no activity on 2023/02/12 03:53
Subsystems: kernel
[Documentation on labels]
First crash: 973d, last: 973d

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

read-write to 0xffff888237d1e1fc of 1 bytes by task 0 on cpu 1:
 tick_nohz_idle_exit+0xa4/0x280 kernel/time/tick-sched.c:1338
 do_idle+0x215/0x250 kernel/sched/idle.c:316
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:400
 start_secondary+0x78/0x80 arch/x86/kernel/smpboot.c:264
 secondary_startup_64_no_verify+0xcf/0xdb

read to 0xffff888237d1e1fc of 1 bytes by task 23958 on cpu 0:
 print_cpu+0x456/0x680 kernel/time/timer_list.c:154
 timer_list_show+0x114/0x180 kernel/time/timer_list.c:291
 seq_read_iter+0x676/0x8e0 fs/seq_file.c:272
 proc_reg_read_iter+0xfa/0x170 fs/proc/inode.c:305
 call_read_iter include/linux/fs.h:2180 [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: 0x01 -> 0x00

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 23958 Comm: syz-executor.2 Not tainted 6.2.0-rc1-syzkaller-00084-gc8451c141e07-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/01/01 03:39 upstream c8451c141e07 ab32d508 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in print_cpu / tick_nohz_idle_exit
* Struck through repros no longer work on HEAD.