syzbot

==================================================================
BUG: KCSAN: data-race in dput / vfs_rename

write to 0xffff88811f158e40 of 4 bytes by task 15358 on cpu 1:
 dont_mount include/linux/dcache.h:354 [inline]
 vfs_rename+0x970/0xba0 fs/namei.c:4313
 do_renameat2+0x554/0x930 fs/namei.c:4450
 __do_sys_rename fs/namei.c:4496 [inline]
 __se_sys_rename fs/namei.c:4494 [inline]
 __x64_sys_rename+0x3a/0x40 fs/namei.c:4494
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88811f158e40 of 4 bytes by task 5037 on cpu 0:
 fast_dput fs/dcache.c:746 [inline]
 dput+0x2f/0x420 fs/dcache.c:865
 __fput+0x32c/0x460 fs/file_table.c:294
 ____fput+0x11/0x20 fs/file_table.c:314
 task_work_run+0x8e/0x110 kernel/task_work.c:135
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:239 [inline]
 __prepare_exit_to_usermode+0x1c6/0x230 arch/x86/entry/common.c:269
 __syscall_return_slowpath+0x47/0x60 arch/x86/entry/common.c:352
 do_syscall_64+0x5d/0xb0 arch/x86/entry/common.c:393
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 5037 Comm: systemd-udevd Not tainted 5.8.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================