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BUG: KCSAN: data-race in __d_instantiate / step_into

write to 0xffff888106535ab0 of 8 bytes by task 3544 on cpu 1:
 __d_set_inode_and_type fs/dcache.c:380 [inline]
 __d_instantiate+0x1fe/0x3c0 fs/dcache.c:1894
 d_instantiate+0x59/0x80 fs/dcache.c:1921
 shmem_mknod+0x153/0x180 mm/shmem.c:3854
 shmem_mkdir+0x33/0x70 mm/shmem.c:3897
 vfs_mkdir+0x1f4/0x320 fs/namei.c:4313
 do_mkdirat+0x136/0x2c0 fs/namei.c:4336
 __do_sys_mkdir fs/namei.c:4356 [inline]
 __se_sys_mkdir fs/namei.c:4354 [inline]
 __x64_sys_mkdir+0x42/0x50 fs/namei.c:4354
 x64_sys_call+0x1b2b/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:84
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888106535ab0 of 8 bytes by task 3541 on cpu 0:
 step_into+0x11d/0x820 fs/namei.c:1956
 open_last_lookups fs/namei.c:3777 [inline]
 path_openat+0x13e5/0x1fc0 fs/namei.c:3986
 do_filp_open+0x107/0x230 fs/namei.c:4016
 io_openat2+0x280/0x3a0 io_uring/openclose.c:140
 io_openat+0x1a/0x30 io_uring/openclose.c:177
 io_issue_sqe+0x1a9/0xb70 io_uring/io_uring.c:1737
 io_queue_sqe io_uring/io_uring.c:1947 [inline]
 io_submit_sqe io_uring/io_uring.c:2204 [inline]
 io_submit_sqes+0x680/0x1070 io_uring/io_uring.c:2321
 __do_sys_io_uring_enter io_uring/io_uring.c:3372 [inline]
 __se_sys_io_uring_enter+0x1c0/0x1b00 io_uring/io_uring.c:3307
 __x64_sys_io_uring_enter+0x78/0x90 io_uring/io_uring.c:3307
 x64_sys_call+0xb5e/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:427
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0xffff888117b5b1e8

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3541 Comm: syz.1.33 Not tainted 6.14.0-rc4-syzkaller-00015-g2a1944bff549 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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