==================================================================
BUG: KCSAN: data-race in __d_instantiate / path_openat

read-write to 0xffff88811b4d4d80 of 4 bytes by task 26 on cpu 0:
 fsnotify_update_flags include/linux/fsnotify_backend.h:-1 [inline]
 __d_instantiate+0x2a8/0x390 fs/dcache.c:2154
 d_make_persistent+0x72/0x110 fs/dcache.c:2978
 shmem_mknod+0x15f/0x170 mm/shmem.c:3851
 vfs_mknod+0x337/0x460 fs/namei.c:5269
 handle_create drivers/base/devtmpfs.c:232 [inline]
 handle drivers/base/devtmpfs.c:384 [inline]
 devtmpfs_work_loop+0x54f/0x860 drivers/base/devtmpfs.c:399
 devtmpfsd+0x48/0x50 drivers/base/devtmpfs.c:441
 kthread+0x223/0x270 kernel/kthread.c:436
 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff88811b4d4d80 of 4 bytes by task 6906 on cpu 1:
 d_managed include/linux/dcache.h:433 [inline]
 step_into fs/namei.c:2140 [inline]
 open_last_lookups fs/namei.c:4780 [inline]
 path_openat+0x572/0x10d0 fs/namei.c:4997
 do_file_open+0x16c/0x290 fs/namei.c:5029
 do_sys_openat2+0xa0/0x130 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_sys_openat fs/open.c:1439 [inline]
 __se_sys_openat fs/open.c:1434 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1434
 x64_sys_call+0x1f72/0x2550 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000080 -> 0x08280080

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 6906 Comm: syz.4.1205 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
==================================================================