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

read to 0xffff8881003a70d0 of 8 bytes by task 11550 on cpu 0:
 do_signal_stop+0x3e3/0x500 kernel/signal.c:2348
 get_signal+0x61b/0x1320 kernel/signal.c:2694
 do_signal+0x2f/0x6c0 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8881003a70d0 of 8 bytes by task 11546 on cpu 1:
 handle_mm_fault+0x4a/0x530 mm/memory.c:4089
 do_user_addr_fault arch/x86/mm/fault.c:1441 [inline]
 __do_page_fault+0x456/0x8d0 arch/x86/mm/fault.c:1506
 do_page_fault+0x38/0x194 arch/x86/mm/fault.c:1530
 page_fault+0x34/0x40 arch/x86/entry/entry_64.S:1203

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 11546 Comm: syz-executor.0 Not tainted 5.5.0-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: 11546 Comm: syz-executor.0 Not tainted 5.5.0-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+0x11d/0x181 lib/dump_stack.c:118
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0xd kernel/kcsan/report.c:313
 kcsan_setup_watchpoint+0x3fe/0x460 kernel/kcsan/core.c:416
 check_access kernel/kcsan/core.c:459 [inline]
 __tsan_unaligned_write8+0xc7/0x110 kernel/kcsan/core.c:589
 handle_mm_fault+0x4a/0x530 mm/memory.c:4089
 do_user_addr_fault arch/x86/mm/fault.c:1441 [inline]
 __do_page_fault+0x456/0x8d0 arch/x86/mm/fault.c:1506
 do_page_fault+0x38/0x194 arch/x86/mm/fault.c:1530
 page_fault+0x34/0x40 arch/x86/entry/entry_64.S:1203
RIP: 0033:0x401c27
Code: 00 00 00 48 83 ec 08 48 8b 15 6d 0a 67 00 48 8b 05 5e 0a 67 00 48 39 d0 48 8d 8a 00 00 00 01 72 17 48 39 c8 73 12 48 8d 50 04 <89> 38 48 89 15 40 0a 67 00 48 83 c4 08 c3 48 89 c6 bf 98 c1 4c 00
RSP: 002b:00007ffd6b1b7390 EFLAGS: 00010287
RAX: 0000001b2dd25000 RBX: 0000000070f499d3 RCX: 0000001b2ed20000
RDX: 0000001b2dd25004 RSI: 0000000000001a8e RDI: 0000000021f6fa8e
RBP: 0000000000000101 R08: 0000000021f6fa92 R09: ffffffffffffffff
R10: 00007ffd6b1b7500 R11: 0000000000000246 R12: 000000000075bfa8
R13: 00007f1f9659c004 R14: 00007f1f9659c000 R15: 000000000000f626
Kernel Offset: disabled
Rebooting in 86400 seconds..