Linux Kernel CVE-2025-40182

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

crypto: skcipher - Fix reqsize handling

Commit afddce13ce81d ("crypto: api - Add reqsize to crypto_alg") introduced cra_reqsize field in crypto_alg struct to replace type specific reqsize fields. It looks like this was introduced specifically for ahash and acomp from the commit description as subsequent commits add necessary changes in these alg frameworks.

However, this is being recommended for use in all crypto algs [1] instead of setting reqsize using crypto_*_set_reqsize(). Using cra_reqsize in skcipher algorithms, hence, causes memory corruptions and crashes as the underlying functions in the algorithm framework have not been updated to set the reqsize properly from cra_reqsize. [2]

Add proper set_reqsize calls in the skcipher init function to properly initialize reqsize for these algorithms in the framework.

[1]: https://lore.kernel.org/linux-crypto/aCL8BxpHr5OpT04k@gondor.apana.org.au/ [2]: https://gist.github.com/Pratham-T/24247446f1faf4b7843e4014d5089f6b

The affected product is the Linux kernel, specifically the crypto/skcipher symmetric-cipher framework, in versions that adopted the cra_reqsize field from commit afddce13ce81d ('crypto: api - Add reqsize to crypto_alg') for skcipher algorithms. No CPE strings, exact tagged version numbers, or distribution-specific advisories were provided in the input; affected versions must be derived from the introducing commit and the stable-tree fix commits at https://git.kernel.org/stable/c/229c586b5e86979badb7cb0d38717b88a9e95ddd and https://git.kernel.org/stable/c/f041339d6b9a5a46437f0c48fc7279c92af7a513. Any kernel build or driver that registers an skcipher algorithm declaring cra_reqsize instead of calling crypto_skcipher_set_reqsize() is exposed.