xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

crypto: ecc - Actually remove stack VLA usage

Browse Source 
On the quest to remove all VLAs from the kernel[1], this avoids VLAs
by just using the maximum allocation size (4 bytes) for stack arrays.
All the VLAs in ecc were either 3 or 4 bytes (or a multiple), so just
make it 4 bytes all the time. Initialization routines are adjusted to
check that ndigits does not end up larger than the arrays.

This includes a removal of the earlier attempt at this fix from
commit a963834b4742 ("crypto/ecc: Remove stack VLA usage")

[1] https://lkml.org/lkml/2018/3/7/621

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Kees Cook
2018-03-30 09:55:44 -07:00
committed by Herbert Xu
parent 3a488aaec6
commit d5c3b17898
3 changed files with 33 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
crypto/ecdh.c
View File

@@ -30,8 +30,8 @@ static inline struct ecdh_ctx *ecdh_get_ctx(struct crypto_kpp *tfm)
static unsigned int ecdh_supported_curve(unsigned int curve_id)
{
switch (curve_id) {
case ECC_CURVE_NIST_P192: return 3;
case ECC_CURVE_NIST_P256: return 4;
case ECC_CURVE_NIST_P192: return ECC_CURVE_NIST_P192_DIGITS;
case ECC_CURVE_NIST_P256: return ECC_CURVE_NIST_P256_DIGITS;
default: return 0;
}
}