Re: [PATCH 3/3] s390/crypto: Enable CONTEXT_ANALYSIS

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Missing error check for `skcipher_walk_virt()` in `ctr_aes_crypt()` causes errors to be silently swallowed.
--

--- Patch [3]: [PATCH 3/3] s390/crypto: Enable CONTEXT_ANALYSIS ---
commit 2232f8277d7ab7cfce4ac97a8923bcf8c4ed60e3
Author: Heiko Carstens <hca@linux.ibm.com>

s390/crypto: Enable CONTEXT_ANALYSIS

Enable CONTEXT_ANALYSIS since s390's crypto code compiles now without
warnings.

> diff --git a/arch/s390/crypto/Makefile b/arch/s390/crypto/Makefile
> index 48aeb0c0ffbd6..1d64208139357 100644
> --- a/arch/s390/crypto/Makefile
> +++ b/arch/s390/crypto/Makefile
> @@ -3,6 +3,8 @@
>  # Cryptographic API
>  #
>  
> +CONTEXT_ANALYSIS := y
> +

[Severity: High]
Does this code silently swallow errors from skcipher_walk_virt()?

In arch/s390/crypto/aes_s390.c:ctr_aes_crypt():

	ret = skcipher_walk_virt(&walk, req, false);

	if (mutex_trylock(&ctrblk_lock)) {
		ret = __ctr_aes_crypt(sctx, &walk, true);
		mutex_unlock(&ctrblk_lock);
	} else {
		ret = __ctr_aes_crypt(sctx, &walk, false);
	}

If memory allocation or scatterlist setup fails during skcipher_walk_virt(),
it returns an error code (such as -ENOMEM or -EINVAL). Because ret is
immediately overwritten by __ctr_aes_crypt() without being checked, the
caller may incorrectly receive 0 (success).

This causes a silent failure where unencrypted or undecrypted data may be
consumed by the caller.

Could we add an error check before calling __ctr_aes_crypt()?

>  obj-$(CONFIG_CRYPTO_AES_S390) += aes_s390.o

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Sashiko AI review · https://sashiko.dev/#/patchset/20260804113736.1423667-1-hca@linux.ibm.com?part=3