syzbot


KCSAN: data-race in rtc_dev_poll / rtc_pie_update_irq (2)

Status: auto-closed as invalid on 2022/02/16 06:16
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 325d, last: 325d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in rtc_dev_poll / rtc_pie_update_irq 1 448d 448d 0/24 auto-closed as invalid on 2021/10/16 01:04

Sample crash report:
==================================================================
BUG: KCSAN: data-race in rtc_dev_poll / rtc_pie_update_irq

write to 0xffff888102fe4388 of 8 bytes by interrupt on cpu 1:
 rtc_handle_legacy_irq drivers/rtc/interface.c:623 [inline]
 rtc_pie_update_irq+0x9b/0xf0 drivers/rtc/interface.c:671
 __run_hrtimer+0x163/0x460 kernel/time/hrtimer.c:1685
 __hrtimer_run_queues kernel/time/hrtimer.c:1749 [inline]
 hrtimer_interrupt+0x37e/0xac0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0xa3/0x240 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x88/0xb0 arch/x86/kernel/apic/apic.c:1097
 asm_sysvec_apic_timer_interrupt+0x12/0x20
 check_kcov_mode kernel/kcov.c:168 [inline]
 __sanitizer_cov_trace_pc+0x33/0x60 kernel/kcov.c:200
 ep_pm_stay_awake fs/eventpoll.c:577 [inline]
 ep_send_events fs/eventpoll.c:1713 [inline]
 ep_poll fs/eventpoll.c:1799 [inline]
 do_epoll_wait+0x8b2/0xf40 fs/eventpoll.c:2227
 __do_sys_epoll_wait fs/eventpoll.c:2239 [inline]
 __se_sys_epoll_wait fs/eventpoll.c:2234 [inline]
 __x64_sys_epoll_wait+0x119/0x140 fs/eventpoll.c:2234
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888102fe4388 of 8 bytes by task 9259 on cpu 0:
 rtc_dev_poll+0x75/0xa0 drivers/rtc/dev.c:198
 vfs_poll include/linux/poll.h:90 [inline]
 do_select+0x7a5/0xeb0 fs/select.c:538
 core_sys_select+0x440/0x6d0 fs/select.c:681
 do_pselect fs/select.c:763 [inline]
 __do_sys_pselect6+0x1ea/0x250 fs/select.c:804
 __se_sys_pselect6 fs/select.c:795 [inline]
 __x64_sys_pselect6+0x74/0x80 fs/select.c:795
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000000ae9c0 -> 0x00000000000aeac0

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9259 Comm: syz-executor.0 Not tainted 5.16.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/01/12 06:14 upstream 6f38be8f2ccd 44d1319a .config log report info KCSAN: data-race in rtc_dev_poll / rtc_pie_update_irq
* Struck through repros no longer work on HEAD.