crypto: ecdh - fix big endian bug in ECC library
commit f398243e9fd6a3a059c1ea7b380c40628dbf0c61 upstream.
The elliptic curve arithmetic library used by the EC-DH KPP implementation
assumes big endian byte order, and unconditionally reverses the byte
and word order of multi-limb quantities. On big endian systems, the byte
reordering is not necessary, while the word ordering needs to be retained.
So replace the __swab64() invocation with a call to be64_to_cpu() which
should do the right thing for both little and big endian builds.
Fixes: 3c4b23901a0c ("crypto: ecdh - Add ECDH software support")
Cc: <stable@vger.kernel.org> # v4.9+
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/crypto/ecc.c b/crypto/ecc.c
index 414c78a..7cf6c3e 100644
--- a/crypto/ecc.c
+++ b/crypto/ecc.c
@@ -897,10 +897,11 @@
static inline void ecc_swap_digits(const u64 *in, u64 *out,
unsigned int ndigits)
{
+ const __be64 *src = (__force __be64 *)in;
int i;
for (i = 0; i < ndigits; i++)
- out[i] = __swab64(in[ndigits - 1 - i]);
+ out[i] = be64_to_cpu(src[ndigits - 1 - i]);
}
int ecc_is_key_valid(unsigned int curve_id, unsigned int ndigits,