==================================================================
BUG: KCSAN: data-race in ksys_read / ksys_write

read to 0xffff8881235be668 of 8 bytes by task 7626 on cpu 1:
 ksys_read+0xa9/0x1b0 fs/read_write.c:584
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x4c/0x60 fs/read_write.c:595
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8881235be668 of 8 bytes by task 7644 on cpu 0:
 ksys_write+0x101/0x1b0 fs/read_write.c:613
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x4c/0x60 fs/read_write.c:620
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7644 Comm: syz-fuzzer Not tainted 5.4.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 7644 Comm: syz-fuzzer Not tainted 5.4.0-rc7+ #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/0x1a kernel/kcsan/report.c:320
 kcsan_setup_watchpoint+0x3fe/0x460 kernel/kcsan/core.c:423
 check_access kernel/kcsan/core.c:468 [inline]
 __tsan_unaligned_write8+0xc4/0x100 kernel/kcsan/core.c:598
 ksys_write+0x101/0x1b0 fs/read_write.c:613
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x4c/0x60 fs/read_write.c:620
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x47c530
Code: 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 49 c7 c2 00 00 00 00 49 c7 c0 00 00 00 00 49 c7 c1 00 00 00 00 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30
RSP: 002b:000000c42b9a9318 EFLAGS: 00000212 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530
RDX: 00000000000000f0 RSI: 000000c420300020 RDI: 0000000000000003
RBP: 000000c42b9a9370 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 000000c4200c1b00
R13: 000000000000007f R14: 0000000000c1dc00 R15: fffffffffffc89fb
Kernel Offset: disabled
Rebooting in 86400 seconds..