CVE-2025-22072

In the Linux kernel, the following vulnerability has been resolved:

spufs: fix gang directory lifetimes

prior to “[POWERPC] spufs: Fix gang destroy leaks” we used to have
a problem with gang lifetimes – creation of a gang returns opened
gang directory, which normally gets removed when that gets closed,
but if somebody has created a context belonging to that gang and
kept it alive until the gang got closed, removal failed and we
ended up with a leak.

Unfortunately, it had been fixed the wrong way. Dentry of gang
directory was no longer pinned, and rmdir on close was gone.
One problem was that failure of open kept calling simple_rmdir()
as cleanup, which meant an unbalanced dput(). Another bug was
in the success case – gang creation incremented link count on
root directory, but that was no longer undone when gang got
destroyed.

Fix consists of
* reverting the commit in question
* adding a counter to gang, protected by ->i_rwsem
of gang directory inode.
* having it set to 1 at creation time, dropped
in both spufs_dir_close() and spufs_gang_close() and bumped
in spufs_create_context(), provided that it’s not 0.
* using simple_recursive_removal() to take the gang
directory out when counter reaches zero.

More information : https://git.kernel.org/stable/c/029d8c711f5e5fe8cf63e8a4a1a140a06e224e45