From: Ard Biesheuvel ardb@kernel.org
commit 17858b140bf49961b71d4e73f1c3ea9bc8e7dda0 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- crypto/ecdh.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
--- a/crypto/ecdh.c +++ b/crypto/ecdh.c @@ -57,12 +57,13 @@ static int ecdh_set_secret(struct crypto 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; }