KCSAN: data-race in get_signal / prepare

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in get_signal / prepare_signal kernel				17	1475d	1631d	0/26	auto-closed as invalid on 2020/06/10 20:37

================================================================== BUG: KCSAN: data-race in get_signal / prepare_signal read-write to 0xffff888131de002c of 4 bytes by task 11883 on cpu 0: get_signal+0xcaa/0x1440 kernel/signal.c:2750 arch_do_signal_or_restart+0x2a/0x270 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x109/0x1a0 kernel/entry/common.c:201 irqentry_exit_to_user_mode+0x5/0x20 kernel/entry/common.c:315 irqentry_exit+0xe/0x40 kernel/entry/common.c:403 sysvec_apic_timer_interrupt+0x80/0x90 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 read to 0xffff888131de002c of 4 bytes by task 8450 on cpu 1: sig_task_ignored kernel/signal.c:94 [inline] sig_ignored kernel/signal.c:119 [inline] prepare_signal+0x872/0xd80 kernel/signal.c:962 __send_signal+0x64/0x780 kernel/signal.c:1082 send_signal+0x39f/0x3d0 kernel/signal.c:1242 do_send_sig_info+0x9b/0xe0 kernel/signal.c:1291 group_send_sig_info kernel/signal.c:1414 [inline] kill_pid_info+0x7f/0x100 kernel/signal.c:1448 kill_proc_info kernel/signal.c:1465 [inline] kill_something_info kernel/signal.c:1562 [inline] __do_sys_kill kernel/signal.c:3680 [inline] __se_sys_kill+0xd3/0x450 kernel/signal.c:3674 __x64_sys_kill+0x2d/0x40 kernel/signal.c:3674 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 8450 Comm: syz-executor.0 Not tainted 5.11.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================