syzbot

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BUG: KCSAN: data-race in __dentry_kill / lookup_fast

write to 0xffff888106baeb40 of 4 bytes by task 17362 on cpu 1:
 dentry_unlist fs/dcache.c:522 [inline]
 __dentry_kill+0x147/0x4e0 fs/dcache.c:578
 dentry_kill fs/dcache.c:695 [inline]
 dput+0xc6/0x360 fs/dcache.c:888
 handle_mounts fs/namei.c:1474 [inline]
 step_into+0x442/0xec0 fs/namei.c:1772
 walk_component+0x190/0x350 fs/namei.c:1948
 link_path_walk+0x4ba/0x780 fs/namei.c:2265
 path_openat+0x1a0/0x20b0 fs/namei.c:3490
 do_filp_open+0xd9/0x1f0 fs/namei.c:3521
 io_openat2+0x268/0x480 fs/io_uring.c:3838
 io_issue_sqe+0x151e/0x6750 fs/io_uring.c:6183
 io_wq_submit_work+0x113/0x270 fs/io_uring.c:6252
 io_worker_handle_work+0x8cb/0xaf0 fs/io-wq.c:496
 io_wqe_worker+0x1c5/0x550 fs/io-wq.c:545
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff888106baeb40 of 4 bytes by task 17359 on cpu 0:
 d_revalidate fs/namei.c:826 [inline]
 lookup_fast+0x15f/0x350 fs/namei.c:1578
 walk_component+0x5c/0x350 fs/namei.c:1938
 link_path_walk+0x4ba/0x780 fs/namei.c:2265
 path_openat+0x1a0/0x20b0 fs/namei.c:3490
 do_filp_open+0xd9/0x1f0 fs/namei.c:3521
 io_openat2+0x268/0x480 fs/io_uring.c:3838
 io_issue_sqe+0x151e/0x6750 fs/io_uring.c:6183
 __io_queue_sqe+0xe9/0x360 fs/io_uring.c:6414
 io_queue_sqe fs/io_uring.c:6463 [inline]
 io_submit_sqe+0x1887/0x3360 fs/io_uring.c:6626
 io_submit_sqes+0x5bd/0xbd0 fs/io_uring.c:6734
 __do_sys_io_uring_enter fs/io_uring.c:9330 [inline]
 __se_sys_io_uring_enter+0x1e1/0xa80 fs/io_uring.c:9272
 __x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:9272
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000008 -> 0x00008008

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 17359 Comm: syz-executor.3 Not tainted 5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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