syzbot

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

write to 0xffff8880b6206024 of 4 bytes by task 10508 on cpu 0:
 freezer_count include/linux/freezer.h:121 [inline]
 freezable_schedule include/linux/freezer.h:173 [inline]
 do_nanosleep+0x121/0x390 kernel/time/hrtimer.c:1879
 hrtimer_nanosleep kernel/time/hrtimer.c:1932 [inline]
 __do_sys_nanosleep kernel/time/hrtimer.c:1966 [inline]
 __se_sys_nanosleep+0x20b/0x2a0 kernel/time/hrtimer.c:1953
 __x64_sys_nanosleep+0x2d/0x40 kernel/time/hrtimer.c:1953
 do_syscall_64+0x71/0x120 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880b6206024 of 4 bytes by task 10512 on cpu 1:
 task_set_jobctl_pending kernel/signal.c:291 [inline]
 do_signal_stop+0x30e/0x6a0 kernel/signal.c:2354
 get_signal+0x66a/0x1520 kernel/signal.c:2699
 do_signal+0x25/0x270 arch/x86/kernel/signal.c:810
 exit_to_usermode_loop arch/x86/entry/common.c:212 [inline]
 __prepare_exit_to_usermode+0x129/0x230 arch/x86/entry/common.c:246
 __syscall_return_slowpath arch/x86/entry/common.c:329 [inline]
 do_syscall_64+0xb9/0x120 arch/x86/entry/common.c:368
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10512 Comm: syz-executor.3 Not tainted 5.8.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 10512 Comm: syz-executor.3 Not tainted 5.8.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x10f/0x19d lib/dump_stack.c:118
 panic+0x1f8/0x63a kernel/panic.c:231
 kcsan_report+0x684/0x690 kernel/kcsan/report.c:626
 kcsan_setup_watchpoint+0x453/0x4d0 kernel/kcsan/core.c:519
 task_set_jobctl_pending kernel/signal.c:291 [inline]
 do_signal_stop+0x30e/0x6a0 kernel/signal.c:2354
 get_signal+0x66a/0x1520 kernel/signal.c:2699
 do_signal+0x25/0x270 arch/x86/kernel/signal.c:810
 exit_to_usermode_loop arch/x86/entry/common.c:212 [inline]
 __prepare_exit_to_usermode+0x129/0x230 arch/x86/entry/common.c:246
 __syscall_return_slowpath arch/x86/entry/common.c:329 [inline]
 do_syscall_64+0xb9/0x120 arch/x86/entry/common.c:368
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45ca59
Code: Bad RIP value.
RSP: 002b:00007f4fea5e6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000013
RAX: fffffffffffffe00 RBX: 00000000004fbce0 RCX: 000000000045ca59
RDX: 0000000000000001 RSI: 0000000020000140 RDI: 0000000000000005
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000008a9 R14: 00000000004cb66e R15: 00007f4fea5e76d4
Shutting down cpus with NMI
Kernel Offset: disabled
Rebooting in 86400 seconds..