syzbot


KCSAN: data-race in print_cpu / tick_irq_enter

Status: auto-closed as invalid on 2021/12/09 16:37
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 418d, last: 387d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in print_cpu / tick_irq_enter (3) 1 55d 55d 0/24 auto-obsoleted due to no activity on 2022/11/06 07:20
upstream KCSAN: data-race in print_cpu / tick_irq_enter (2) 1 110d 110d 0/24 auto-closed as invalid on 2022/09/11 23:24

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

write to 0xffff888237d1dee8 of 8 bytes by interrupt on cpu 1:
 update_ts_time_stats kernel/time/tick-sched.c:638 [inline]
 tick_nohz_stop_idle kernel/time/tick-sched.c:648 [inline]
 tick_nohz_irq_enter kernel/time/tick-sched.c:1377 [inline]
 tick_irq_enter+0x15c/0x240 kernel/time/tick-sched.c:1396
 common_interrupt+0x8f/0xc0 arch/x86/kernel/irq.c:240
 asm_common_interrupt+0x1e/0x40
 native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
 arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
 acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline]
 acpi_idle_do_entry drivers/acpi/processor_idle.c:553 [inline]
 acpi_idle_enter+0x282/0x300 drivers/acpi/processor_idle.c:688
 cpuidle_enter_state+0x2b4/0x7d0 drivers/cpuidle/cpuidle.c:237
 cpuidle_enter+0x3c/0x60 drivers/cpuidle/cpuidle.c:351
 call_cpuidle kernel/sched/idle.c:158 [inline]
 cpuidle_idle_call kernel/sched/idle.c:239 [inline]
 do_idle+0x1b2/0x250 kernel/sched/idle.c:306
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:403
 secondary_startup_64_no_verify+0xb1/0xbb

read to 0xffff888237d1dee8 of 8 bytes by task 29263 on cpu 0:
 print_cpu+0x4fe/0x690 kernel/time/timer_list.c:158
 timer_list_show+0x114/0x180 kernel/time/timer_list.c:291
 seq_read_iter+0x60b/0x930 fs/seq_file.c:272
 proc_reg_read_iter+0xfc/0x170 fs/proc/inode.c:300
 call_read_iter include/linux/fs.h:2155 [inline]
 generic_file_splice_read+0x24f/0x330 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870
 do_splice_direct+0x106/0x190 fs/splice.c:979
 do_sendfile+0x675/0xc40 fs/read_write.c:1245
 __do_sys_sendfile64 fs/read_write.c:1310 [inline]
 __se_sys_sendfile64 fs/read_write.c:1296 [inline]
 __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1296
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000009b58fe38b9 -> 0x0000009b59052e08

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 29263 Comm: syz-executor.1 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/11/04 16:30 upstream 7ddb58cb0eca 4c1be0be .config log report info KCSAN: data-race in print_cpu / tick_irq_enter
ci2-upstream-kcsan-gce 2021/10/04 17:12 upstream 9e1ff307c779 ce697b49 .config log report info KCSAN: data-race in print_cpu / tick_irq_enter
* Struck through repros no longer work on HEAD.