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authorArd Biesheuvel <ardb@kernel.org>2020-11-24 11:47:19 +0100
committerHerbert Xu <herbert@gondor.apana.org.au>2020-12-04 18:13:13 +1100
commit17858b140bf49961b71d4e73f1c3ea9bc8e7dda0 (patch)
tree89b0f162292703ef55bf19475fc3156da73b96f8
parent05c2a705917b77e0915cca3551583583f4eafcf8 (diff)
downloadlinux-17858b140bf49961b71d4e73f1c3ea9bc8e7dda0.tar.bz2
crypto: ecdh - avoid unaligned accesses in ecdh_set_secret()
ecdh_set_secret() casts a void* pointer to a const u64* in order to feed it into ecc_is_key_valid(). This is not generally permitted by the C standard, and leads to actual misalignment faults on ARMv6 cores. In some cases, these are fixed up in software, but this still leads to performance hits that are entirely avoidable. So let's copy the key into the ctx buffer first, which we will do anyway in the common case, and which guarantees correct alignment. Cc: <stable@vger.kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--crypto/ecdh.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/crypto/ecdh.c b/crypto/ecdh.c
index b0232d6ab4ce..d56b8603dec9 100644
--- a/crypto/ecdh.c
+++ b/crypto/ecdh.c
@@ -53,12 +53,13 @@ static int ecdh_set_secret(struct crypto_kpp *tfm, const void *buf,
return ecc_gen_privkey(ctx->curve_id, ctx->ndigits,
ctx->private_key);
- if (ecc_is_key_valid(ctx->curve_id, ctx->ndigits,
- (const u64 *)params.key, params.key_size) < 0)
- return -EINVAL;
-
memcpy(ctx->private_key, params.key, params.key_size);
+ if (ecc_is_key_valid(ctx->curve_id, ctx->ndigits,
+ ctx->private_key, params.key_size) < 0) {
+ memzero_explicit(ctx->private_key, params.key_size);
+ return -EINVAL;
+ }
return 0;
}