syzbot

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BUG: KCSAN: data-race in __d_lookup_rcu / __dput_to_list

read to 0xffff888141573780 of 4 bytes by task 21147 on cpu 1:
 __d_lookup_rcu+0x42/0x290 fs/dcache.c:2360
 lookup_fast+0x8e/0x290 fs/namei.c:1629
 walk_component+0x3f/0x230 fs/namei.c:1998
 lookup_last fs/namei.c:2459 [inline]
 path_lookupat+0x10a/0x2a0 fs/namei.c:2483
 filename_lookup+0x126/0x300 fs/namei.c:2512
 user_path_at_empty+0x42/0x110 fs/namei.c:2911
 user_path_at include/linux/namei.h:57 [inline]
 do_mount fs/namespace.c:3674 [inline]
 __do_sys_mount fs/namespace.c:3886 [inline]
 __se_sys_mount+0x24b/0x2d0 fs/namespace.c:3863
 __x64_sys_mount+0x67/0x80 fs/namespace.c:3863
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read-write to 0xffff888141573780 of 4 bytes by task 21143 on cpu 0:
 d_shrink_add fs/dcache.c:456 [inline]
 __dput_to_list+0x1eb/0x240 fs/dcache.c:928
 shrink_dentry_list+0x196/0x380 fs/dcache.c:1200
 shrink_dcache_sb+0x165/0x290 fs/dcache.c:1321
 reconfigure_super+0x3ef/0x580 fs/super.c:1121
 do_remount fs/namespace.c:2884 [inline]
 path_mount+0x969/0xb30 fs/namespace.c:3656
 do_mount fs/namespace.c:3677 [inline]
 __do_sys_mount fs/namespace.c:3886 [inline]
 __se_sys_mount+0x27f/0x2d0 fs/namespace.c:3863
 __x64_sys_mount+0x67/0x80 fs/namespace.c:3863
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 21143 Comm: syz-executor.5 Not tainted 6.7.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
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EXT4-fs (sda1): re-mounted 5941fea2-f5fa-4b4e-b5ef-9af118b27b95 r/w. Quota mode: none.