KCSAN: data-race in do_nanosleep / do_signal_stop (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: b6505459 Linux 5.10-rc6
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16700c45500000
kernel config: https://syzkaller.appspot.com/x/.config?x=c949fed53798f819
dashboard link: https://syzkaller.appspot.com/bug?extid=6d31bb7ecfb11f3746b6
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [linux-...@vger.kernel.org tg...@linutronix.de]

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6d31bb...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in do_nanosleep / do_signal_stop

read-write to 0xffff888131d5d024 of 4 bytes by task 10147 on cpu 1:
freezer_do_not_count include/linux/freezer.h:109 [inline]
freezable_schedule include/linux/freezer.h:171 [inline]
do_nanosleep+0xf7/0x390 kernel/time/hrtimer.c:1878
hrtimer_nanosleep kernel/time/hrtimer.c:1931 [inline]
__do_sys_nanosleep kernel/time/hrtimer.c:1965 [inline]
__se_sys_nanosleep+0x20b/0x2a0 kernel/time/hrtimer.c:1952
__x64_sys_nanosleep+0x2d/0x40 kernel/time/hrtimer.c:1952
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888131d5d024 of 4 bytes by task 10152 on cpu 0:
task_set_jobctl_pending kernel/signal.c:291 [inline]
do_signal_stop+0x32e/0x6b0 kernel/signal.c:2355
get_signal+0xa83/0x1510 kernel/signal.c:2718
arch_do_signal+0x25/0x260 arch/x86/kernel/signal.c:811
exit_to_user_mode_loop kernel/entry/common.c:161 [inline]
exit_to_user_mode_prepare+0xde/0x170 kernel/entry/common.c:191
syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10152 Comm: syz-executor.5 Not tainted 5.10.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.