syzbot

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BUG: KCSAN: data-race in ___d_drop / __d_lookup

write to 0xffff8881065bcb50 of 8 bytes by task 11 on cpu 0:
 __hlist_bl_del include/linux/list_bl.h:128 [inline]
 ___d_drop+0xe1/0x200 fs/dcache.c:523
 __d_drop fs/dcache.c:530 [inline]
 d_invalidate+0x54/0x1c0 fs/dcache.c:1607
 proc_invalidate_siblings_dcache+0x1db/0x2b0 fs/proc/inode.c:142
 proc_sys_invalidate_dcache fs/proc/proc_sysctl.c:289 [inline]
 start_unregistering fs/proc/proc_sysctl.c:316 [inline]
 drop_sysctl_table+0xbb/0x260 fs/proc/proc_sysctl.c:1513
 drop_sysctl_table+0x1cd/0x260 fs/proc/proc_sysctl.c:1520
 unregister_sysctl_table+0x30/0x50 fs/proc/proc_sysctl.c:1538
 unregister_net_sysctl_table+0x15/0x20 net/sysctl_net.c:177
 xfrm6_net_sysctl_exit net/ipv6/xfrm6_policy.c:233 [inline]
 xfrm6_net_exit+0x3e/0x90 net/ipv6/xfrm6_policy.c:267
 ops_exit_list net/core/net_namespace.c:172 [inline]
 cleanup_net+0x47b/0x860 net/core/net_namespace.c:648
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3317
 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3398
 kthread+0x1d1/0x210 kernel/kthread.c:389
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read to 0xffff8881065bcb50 of 8 bytes by task 3037 on cpu 1:
 hlist_bl_unhashed include/linux/list_bl.h:54 [inline]
 d_unhashed include/linux/dcache.h:354 [inline]
 __d_lookup+0xf1/0x370 fs/dcache.c:2341
 lookup_fast+0x4c/0x2a0 fs/namei.c:1749
 walk_component fs/namei.c:2108 [inline]
 link_path_walk+0x464/0x820 fs/namei.c:2477
 path_openat+0x1af/0x1fa0 fs/namei.c:3983
 do_filp_open+0x107/0x230 fs/namei.c:4014
 do_sys_openat2+0xab/0x120 fs/open.c:1402
 do_sys_open fs/open.c:1417 [inline]
 __do_sys_openat fs/open.c:1433 [inline]
 __se_sys_openat fs/open.c:1428 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1428
 x64_sys_call+0x2b30/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:258
 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: 0xffff88810651cf08 -> 0xffff8881065bc608

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3037 Comm: dhcpcd Not tainted 6.13.0-rc7-syzkaller-00191-gfda5e3f28400 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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