syzbot

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BUG: KCSAN: data-race in __dentry_kill / fast_dput

write to 0xffff888106f1acd0 of 8 bytes by task 10521 on cpu 0:
 __d_drop fs/dcache.c:566 [inline]
 __dentry_kill+0x13e/0x4c0 fs/dcache.c:658
 dput+0x5c/0xd0 fs/dcache.c:902
 handle_mounts fs/namei.c:1640 [inline]
 step_into+0x226/0x860 fs/namei.c:1966
 open_last_lookups fs/namei.c:3792 [inline]
 path_openat+0x141f/0x2000 fs/namei.c:4001
 do_filp_open+0x115/0x240 fs/namei.c:4031
 io_openat2+0x284/0x3a0 io_uring/openclose.c:140
 io_openat+0x1a/0x30 io_uring/openclose.c:177
 __io_issue_sqe io_uring/io_uring.c:1734 [inline]
 io_issue_sqe+0x1a9/0xaf0 io_uring/io_uring.c:1753
 io_wq_submit_work+0x3fb/0x550 io_uring/io_uring.c:1868
 io_worker_handle_work+0x487/0x9f0 io_uring/io-wq.c:615
 io_wq_worker+0x277/0x850 io_uring/io-wq.c:669
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888106f1acd0 of 8 bytes by task 10525 on cpu 1:
 hlist_bl_unhashed include/linux/list_bl.h:54 [inline]
 d_unhashed include/linux/dcache.h:365 [inline]
 retain_dentry fs/dcache.c:743 [inline]
 fast_dput+0x65/0x2c0 fs/dcache.c:839
 dput+0x24/0xd0 fs/dcache.c:896
 handle_mounts fs/namei.c:1640 [inline]
 step_into+0x226/0x860 fs/namei.c:1966
 open_last_lookups fs/namei.c:3792 [inline]
 path_openat+0x141f/0x2000 fs/namei.c:4001
 do_filp_open+0x115/0x240 fs/namei.c:4031
 io_openat2+0x284/0x3a0 io_uring/openclose.c:140
 io_openat+0x1a/0x30 io_uring/openclose.c:177
 __io_issue_sqe io_uring/io_uring.c:1734 [inline]
 io_issue_sqe+0x1a9/0xaf0 io_uring/io_uring.c:1753
 io_wq_submit_work+0x3fb/0x550 io_uring/io_uring.c:1868
 io_worker_handle_work+0x487/0x9f0 io_uring/io-wq.c:615
 io_wq_worker+0x277/0x850 io_uring/io-wq.c:669
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0xffff888237b446e0 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 10525 Comm: iou-wrk-10512 Not tainted 6.14.0-syzkaller-11144-g1e7857b28020 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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