KCSAN: data-race in do_signal_stop / task_dump

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in do_signal_stop / task_dump_owner (2) kernel				1	1228d	1228d	0/26	auto-closed as invalid on 2021/01/18 08:17

================================================================== BUG: KCSAN: data-race in do_signal_stop / task_dump_owner write to 0xffff8880ab2640a4 of 4 bytes by task 18257 on cpu 1: freezer_do_not_count include/linux/freezer.h:109 [inline] freezable_schedule include/linux/freezer.h:171 [inline] do_signal_stop+0x1cf/0x4e0 kernel/signal.c:2395 get_signal+0x601/0x1290 kernel/signal.c:2699 do_signal+0x2b/0x840 arch/x86/kernel/signal.c:784 exit_to_usermode_loop+0x24a/0x2c0 arch/x86/entry/common.c:161 prepare_exit_to_usermode+0x194/0x1e0 arch/x86/entry/common.c:196 swapgs_restore_regs_and_return_to_usermode+0x0/0x40 read to 0xffff8880ab2640a4 of 4 bytes by task 18260 on cpu 0: task_dump_owner+0x42/0x250 fs/proc/base.c:1789 pid_update_inode+0x35/0x70 fs/proc/base.c:1931 pid_revalidate+0x89/0x110 fs/proc/base.c:1954 d_revalidate fs/namei.c:754 [inline] d_revalidate fs/namei.c:751 [inline] lookup_fast+0x38c/0x3a0 fs/namei.c:1486 walk_component+0x6a/0x390 fs/namei.c:1842 link_path_walk.part.0+0x37a/0x700 fs/namei.c:2166 link_path_walk fs/namei.c:2098 [inline] path_openat+0x191/0x23d0 fs/namei.c:3342 do_filp_open+0x11e/0x1b0 fs/namei.c:3373 do_sys_openat2+0x52e/0x680 fs/open.c:1148 do_sys_open+0xa2/0x110 fs/open.c:1164 ksys_open include/linux/syscalls.h:1386 [inline] __do_sys_open fs/open.c:1170 [inline] __se_sys_open fs/open.c:1168 [inline] __x64_sys_open+0x50/0x60 fs/open.c:1168 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 18260 Comm: syz-executor.2 Not tainted 5.7.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================