| Message ID | 20191023095044.12319-1-ard.biesheuvel@linaro.org |
|---|---|
| State | Accepted |
| Commit | f398243e9fd6a3a059c1ea7b380c40628dbf0c61 |
| Headers | show |
| Series | crypto: ecdh - fix big endian bug in ECC library | expand |
On Wed, Oct 23, 2019 at 11:50:44AM +0200, Ard Biesheuvel wrote: > 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. > > Cc: <stable@vger.kernel.org> # v4.9+ > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > crypto/ecc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) Patch applied. Thanks. -- Email: Herbert Xu <herbert@gondor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
diff --git a/crypto/ecc.c b/crypto/ecc.c index dfe114bc0c4a..8ee787723c5c 100644 --- a/crypto/ecc.c +++ b/crypto/ecc.c @@ -1284,10 +1284,11 @@ EXPORT_SYMBOL(ecc_point_mult_shamir); 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,
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. Cc: <stable@vger.kernel.org> # v4.9+ Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- crypto/ecc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) -- 2.20.1