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BUG: KCSAN: data-race in __d_instantiate / step_into

write to 0xffff8881063f9ab0 of 8 bytes by task 18207 on cpu 1:
 __d_set_inode_and_type fs/dcache.c:344 [inline]
 __d_instantiate+0x1f9/0x3c0 fs/dcache.c:1853
 d_instantiate_new+0x5c/0xf0 fs/dcache.c:1899
 ext4_add_nondir+0x16c/0x1a0 fs/ext4/namei.c:2797
 ext4_symlink+0x4dd/0x5a0 fs/ext4/namei.c:3433
 vfs_symlink+0xca/0x1d0 fs/namei.c:4489
 do_symlinkat+0xe3/0x350 fs/namei.c:4515
 __do_sys_symlink fs/namei.c:4536 [inline]
 __se_sys_symlink fs/namei.c:4534 [inline]
 __x64_sys_symlink+0x56/0x70 fs/namei.c:4534
 x64_sys_call+0x14d2/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:89
 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 0xffff8881063f9ab0 of 8 bytes by task 18206 on cpu 0:
 step_into+0x123/0x810 fs/namei.c:1846
 walk_component+0x169/0x230 fs/namei.c:2010
 lookup_last fs/namei.c:2469 [inline]
 path_lookupat+0x10a/0x2b0 fs/namei.c:2493
 filename_lookup+0x127/0x300 fs/namei.c:2522
 user_path_at_empty+0x42/0x120 fs/namei.c:2929
 user_path_at include/linux/namei.h:58 [inline]
 do_fchmodat fs/open.c:696 [inline]
 __do_sys_chmod fs/open.c:722 [inline]
 __se_sys_chmod fs/open.c:720 [inline]
 __x64_sys_chmod+0x6b/0x120 fs/open.c:720
 x64_sys_call+0x86c/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:91
 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 -> 0xffff88811149ca48

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 18206 Comm: syz.0.4449 Tainted: G        W          6.10.0-rc5-syzkaller-00282-g8282d5af7be8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
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