Messages in this thread | | | Date | Mon, 21 Oct 2019 03:34:07 -0700 | Subject | KCSAN: data-race in exit_signals / prepare_signal | From | syzbot <> |
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Hello,
syzbot found the following crash on:
HEAD commit: d724f94f x86, kcsan: Enable KCSAN for x86 git tree: https://github.com/google/ktsan.git kcsan console output: https://syzkaller.appspot.com/x/log.txt?x=13eab79f600000 kernel config: https://syzkaller.appspot.com/x/.config?x=c0906aa620713d80 dashboard link: https://syzkaller.appspot.com/bug?extid=492a4acccd8fc75ddfd0 compiler: gcc (GCC) 9.0.0 20181231 (experimental)
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+492a4acccd8fc75ddfd0@syzkaller.appspotmail.com
================================================================== BUG: KCSAN: data-race in exit_signals / prepare_signal
read to 0xffff888103566064 of 4 bytes by interrupt on cpu 0: sig_task_ignored kernel/signal.c:94 [inline] sig_ignored kernel/signal.c:119 [inline] prepare_signal+0x1f5/0x790 kernel/signal.c:956 send_sigqueue+0xc1/0x4b0 kernel/signal.c:1859 posix_timer_event kernel/time/posix-timers.c:328 [inline] posix_timer_fn+0x10d/0x230 kernel/time/posix-timers.c:354 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x288/0x600 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0xdc/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 arch_local_irq_enable arch/x86/include/asm/paravirt.h:778 [inline] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x4e/0x80 kernel/locking/spinlock.c:199 spin_unlock_irq include/linux/spinlock.h:388 [inline] get_signal+0x1f4/0x1320 kernel/signal.c:2707 do_signal+0x3b/0xc00 arch/x86/kernel/signal.c:815 exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:159 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x2d7/0x2f0 arch/x86/entry/common.c:299 entry_SYSCALL_64_after_hwframe+0x44/0xa9
write to 0xffff888103566064 of 4 bytes by task 7604 on cpu 1: exit_signals+0x13b/0x490 kernel/signal.c:2822 do_exit+0x1af/0x18e0 kernel/exit.c:825 do_group_exit+0xb4/0x1c0 kernel/exit.c:983 __do_sys_exit_group kernel/exit.c:994 [inline] __se_sys_exit_group kernel/exit.c:992 [inline] __x64_sys_exit_group+0x2e/0x30 kernel/exit.c:992 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9
Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 7604 Comm: syz-executor.4 Not tainted 5.3.0+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================
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