From cfb63e86ff0ebfd7419d1cb85a6c55d4b9380613 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Wed, 23 Oct 2019 11:50:44 +0200 Subject: [PATCH] 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: # v4.9+ Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/ecc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/crypto/ecc.c b/crypto/ecc.c index 3b422e24e647e..65ee29dda063f 100644 --- a/crypto/ecc.c +++ b/crypto/ecc.c @@ -898,10 +898,11 @@ static void ecc_point_mult(struct ecc_point *result, 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]); } static int __ecc_is_key_valid(const struct ecc_curve *curve, -- 2.39.2