In the Linux kernel, the following vulnerability has been resolved:fs/fhandle.c: fix a race in call of has_locked_children()may_decode_fh() is calling has_locked_children() while holding no locks.
That's an oopsable race...The rest of the callers are safe since they are holding namespace_sem and
are guaranteed a positive refcount on the mount in question.Rename the current has_locked_children() to __has_locked_children(), make
it static and switch the fs/namespace.c users to it.Make has_locked_children() a wrapper for __has_locked_children(), calling
the latter under read_seqlock_excl(&mount_lock).