Before releasing the global mutex, we only unlink the hashtable
from the hash list, its proc file is still not unregistered at
this point. So syzbot could trigger a race condition where a
parallel htable_create() could register the same file immediately
after the mutex is released.
Move htable_remove_proc_entry() back to mutex protection to
fix this. And, fold htable_destroy() into htable_put() to make
the code slightly easier to understand.
Reported-and-tested-by: [email protected]
Fixes: c4a3922d2d ("netfilter: xt_hashlimit: reduce hashlimit_mutex scope for htable_put()")
Signed-off-by: Cong Wang <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>