==================================================================
BUG: KCSAN: data-race in fsnotify / fsnotify

write to 0xffff8881041443e8 of 4 bytes by task 7039 on cpu 1:
 send_to_group fs/notify/fsnotify.c:206 [inline]
 fsnotify+0x41e/0x7d0 fs/notify/fsnotify.c:368
 fsnotify_path include/linux/fsnotify.h:54 [inline]
 fsnotify_path include/linux/fsnotify.h:47 [inline]
 fsnotify_modify include/linux/fsnotify.h:256 [inline]
 vfs_write fs/read_write.c:560 [inline]
 vfs_write+0x373/0x390 fs/read_write.c:542
 ksys_write+0xd5/0x1b0 fs/read_write.c:611
 __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

read to 0xffff8881041443e8 of 4 bytes by task 7893 on cpu 0:
 send_to_group fs/notify/fsnotify.c:218 [inline]
 fsnotify+0x4c1/0x7d0 fs/notify/fsnotify.c:368
 fsnotify_path include/linux/fsnotify.h:54 [inline]
 fsnotify_path include/linux/fsnotify.h:47 [inline]
 fsnotify_access include/linux/fsnotify.h:240 [inline]
 vfs_read fs/read_write.c:463 [inline]
 vfs_read+0x29b/0x2c0 fs/read_write.c:446
 ksys_read+0xd5/0x1b0 fs/read_write.c:587
 __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

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7893 Comm: blkid Not tainted 5.4.0-rc3+ #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: 7893 Comm: blkid Not tainted 5.4.0-rc3+ #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+0xf5/0x159 lib/dump_stack.c:113
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0x10 kernel/kcsan/report.c:302
 __kcsan_setup_watchpoint+0x32e/0x4a0 kernel/kcsan/core.c:411
 __tsan_read4 kernel/kcsan/kcsan.c:35 [inline]
 __tsan_read4+0x2c/0x30 kernel/kcsan/kcsan.c:35
 send_to_group fs/notify/fsnotify.c:218 [inline]
 fsnotify+0x4c1/0x7d0 fs/notify/fsnotify.c:368
 fsnotify_path include/linux/fsnotify.h:54 [inline]
 fsnotify_path include/linux/fsnotify.h:47 [inline]
 fsnotify_access include/linux/fsnotify.h:240 [inline]
 vfs_read fs/read_write.c:463 [inline]
 vfs_read+0x29b/0x2c0 fs/read_write.c:446
 ksys_read+0xd5/0x1b0 fs/read_write.c:587
 __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
RIP: 0033:0x7f72c1ecb207
Code: 73 01 c3 48 8d 0d 9d af 20 00 31 d2 48 29 c2 89 11 48 83 c8 ff eb eb 90 90 90 90 90 90 90 90 90 90 90 90 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8d 0d 6d af 20 00 31 d2 48 29 c2 89
RSP: 002b:00007ffec91dc828 EFLAGS: 00000206 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f72c20d61c8 RCX: 00007f72c1ecb207
RDX: 0000000000000340 RSI: 00007ffec91dc948 RDI: 0000000000000003
RBP: 00007ffec91dc8a0 R08: 00007ffec91dcc9f R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000206 R12: 0000000000000008
R13: 00007f72c20d5040 R14: 00007ffec91dc948 R15: 00007ffec91dcc9f
Kernel Offset: disabled
Rebooting in 86400 seconds..