commit 44e8241c51f762aafa50ed116da68fd6ecdcc954 upstream.
On big endian arm kernels, the arm optimized Curve25519 code produces incorrect outputs and fails the Curve25519 test. This has been true ever since this code was added.
It seems that hardly anyone (or even no one?) actually uses big endian arm kernels. But as long as they're ostensibly supported, we should disable this code on them so that it's not accidentally used.
Note: for future-proofing, use !CPU_BIG_ENDIAN instead of CPU_LITTLE_ENDIAN. Both of these are arch-specific options that could get removed in the future if big endian support gets dropped.
Fixes: d8f1308a025f ("crypto: arm/curve25519 - wire up NEON implementation") Cc: stable@vger.kernel.org Acked-by: Ard Biesheuvel ardb@kernel.org Link: https://lore.kernel.org/r/20251104054906.716914-1-ebiggers@kernel.org Signed-off-by: Eric Biggers ebiggers@kernel.org --- arch/arm/crypto/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/crypto/Kconfig b/arch/arm/crypto/Kconfig index 3858c4d4cb98..f6323b84631f 100644 --- a/arch/arm/crypto/Kconfig +++ b/arch/arm/crypto/Kconfig @@ -2,11 +2,11 @@
menu "Accelerated Cryptographic Algorithms for CPU (arm)"
config CRYPTO_CURVE25519_NEON tristate "Public key crypto: Curve25519 (NEON)" - depends on KERNEL_MODE_NEON + depends on KERNEL_MODE_NEON && !CPU_BIG_ENDIAN select CRYPTO_LIB_CURVE25519_GENERIC select CRYPTO_ARCH_HAVE_LIB_CURVE25519 help Curve25519 algorithm
base-commit: f6e38ae624cf7eb96fb444a8ca2d07caa8d9c8fe