AZL-96093

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

keys: make keyring key-chunk byte order agree with keyringdiffobjects()

keyringgetkeychunk() loads description bytes into the index chunk low address first, while keyringdiff_objects() numbers the first differing bit from the low end and folds the absolute byte index into the level without removing the inline-prefix offset the level already carries. The two disagree on byte order and bit position, so the array can be told two keys first differ at a bit that does not differ in the chunk the walker uses, letting crafted descriptions collide into one node.

Load the chunk in the order keyringdiffobjects() assumes and drop the inline-prefix length when folding the byte index into the level. This only changes the in-memory ordering used to place keys within a keyring; add, search and read of non-colliding keys are unaffected.