syzbot

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

read-write to 0xffff88810667a9c0 of 4 bytes by task 5633 on cpu 1:
 __d_instantiate+0x2d5/0x3c0 fs/dcache.c:1879
 d_instantiate+0x59/0x80 fs/dcache.c:1904
 shmem_symlink+0x36a/0x3a0 mm/shmem.c:3966
 vfs_symlink+0xca/0x1d0 fs/namei.c:4669
 do_symlinkat+0xdf/0x350 fs/namei.c:4695
 __do_sys_symlinkat fs/namei.c:4711 [inline]
 __se_sys_symlinkat fs/namei.c:4708 [inline]
 __x64_sys_symlinkat+0x5e/0x70 fs/namei.c:4708
 x64_sys_call+0x269e/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:267
 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 0xffff88810667a9c0 of 4 bytes by task 5630 on cpu 0:
 __follow_mount_rcu fs/namei.c:1570 [inline]
 handle_mounts fs/namei.c:1621 [inline]
 step_into+0xe7/0x840 fs/namei.c:1950
 open_last_lookups fs/namei.c:3775 [inline]
 path_openat+0x1234/0x1fa0 fs/namei.c:3984
 do_filp_open+0x107/0x230 fs/namei.c:4014
 io_openat2+0x280/0x3a0 io_uring/openclose.c:140
 io_openat+0x1a/0x30 io_uring/openclose.c:177
 io_issue_sqe+0x181/0xc10 io_uring/io_uring.c:1740
 io_queue_sqe io_uring/io_uring.c:1950 [inline]
 io_submit_sqe io_uring/io_uring.c:2205 [inline]
 io_submit_sqes+0x64d/0x1090 io_uring/io_uring.c:2322
 __do_sys_io_uring_enter io_uring/io_uring.c:3395 [inline]
 __se_sys_io_uring_enter+0x1b9/0x1ba0 io_uring/io_uring.c:3330
 __x64_sys_io_uring_enter+0x78/0x90 io_uring/io_uring.c:3330
 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: 0x00000008 -> 0x00600008

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 5630 Comm: syz.6.647 Not tainted 6.13.0-rc6-syzkaller-00038-g09a0fa92e5b4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================