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BUG: KCSAN: data-race in dentry_kill / fast_dput

write to 0xffff8881072ba610 of 8 bytes by task 6767 on cpu 1:
 __d_drop fs/dcache.c:578 [inline]
 dentry_kill+0x139/0x500 fs/dcache.c:824
 finish_dput+0x16/0x1d0 fs/dcache.c:1001
 dput+0x48/0x50 fs/dcache.c:1042
 end_dirop fs/namei.c:2956 [inline]
 end_creating include/linux/namei.h:117 [inline]
 end_creating_path fs/namei.c:4995 [inline]
 filename_symlinkat+0x11f/0x2b0 fs/namei.c:5687
 __do_sys_symlinkat fs/namei.c:5705 [inline]
 __se_sys_symlinkat+0x43/0x1b0 fs/namei.c:5700
 __x64_sys_symlinkat+0x43/0x50 fs/namei.c:5700
 x64_sys_call+0x2b7d/0x3020 arch/x86/include/generated/asm/syscalls_64.h:267
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881072ba610 of 8 bytes by task 6763 on cpu 0:
 hlist_bl_unhashed include/linux/list_bl.h:54 [inline]
 d_unhashed include/linux/dcache.h:396 [inline]
 retain_dentry fs/dcache.c:872 [inline]
 fast_dput+0x64/0x2e0 fs/dcache.c:971
 dput+0x1f/0x50 fs/dcache.c:1040
 end_dirop fs/namei.c:2956 [inline]
 end_creating include/linux/namei.h:117 [inline]
 end_creating_path fs/namei.c:4995 [inline]
 filename_mknodat+0x2cb/0x450 fs/namei.c:5199
 __do_sys_mknod fs/namei.c:5222 [inline]
 __se_sys_mknod+0x37/0xf0 fs/namei.c:5219
 __x64_sys_mknod+0x43/0x50 fs/namei.c:5219
 x64_sys_call+0x2acd/0x3020 arch/x86/include/generated/asm/syscalls_64.h:134
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff8882375aeda8 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 6763 Comm: syz.4.876 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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