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.
                
            Metrics
Affected Vendors & Products
References
        History
                    Wed, 29 Oct 2025 11:00:00 +0000
| Type | Values Removed | Values Added | 
|---|---|---|
| First Time appeared | Linux Linux linux Kernel | |
| Vendors & Products | Linux Linux linux Kernel | 
Wed, 29 Oct 2025 00:15:00 +0000
| Type | Values Removed | Values Added | 
|---|---|---|
| References |  | |
| Metrics | threat_severity 
 | cvssV3_1 
 
 | 
Tue, 28 Oct 2025 12:00:00 +0000
| Type | Values Removed | Values Added | 
|---|---|---|
| Description | 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. | |
| Title | crypto: comp - Use same definition of context alloc and free ops | |
| References |  | 
 MITRE
                        MITRE
                    Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-10-28T11:48:34.549Z
Reserved: 2025-04-16T07:20:57.159Z
Link: CVE-2025-40063
 Vulnrichment
                        Vulnrichment
                    No data.
 NVD
                        NVD
                    Status : Awaiting Analysis
Published: 2025-10-28T12:15:40.730
Modified: 2025-10-30T15:05:32.197
Link: CVE-2025-40063
 Redhat
                        Redhat