CVE-2025-40063

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

crypto: comp – Use same definition of context alloc and free ops

In commit 42d9f6c77479 (“crypto: acomp – Move scomp stream allocation
code into acomp”), the crypto_acomp_streams struct was made to rely on
having the alloc_ctx and free_ctx operations defined in the same order
as the scomp_alg struct. But in that same commit, the alloc_ctx and
free_ctx members of scomp_alg may be randomized by structure layout
randomization, since they are contained in a pure ops structure
(containing only function pointers). If the pointers within scomp_alg
are randomized, but those in crypto_acomp_streams are not, then
the order may no longer match. This fixes the problem by removing the
union from scomp_alg so that both crypto_acomp_streams and scomp_alg
will share the same definition of alloc_ctx and free_ctx, ensuring
they will always have the same layout.

More information : https://git.kernel.org/stable/c/779d3b6f2d32c5f1da6163e959abe1e1ffe2945b