From 20067f737dc05a495c99a063d135dfecb56b3e4f Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 11 Nov 2025 12:29:46 -0800 Subject: [PATCH] lib/crypto: arm/curve25519: Disable on CPU_BIG_ENDIAN 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 Link: https://lore.kernel.org/r/20251104054906.716914-1-ebiggers@kernel.org Signed-off-by: Eric Biggers Signed-off-by: Sasha Levin --- 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 149a5bd6b88c..d3d318df0e38 100644 --- a/arch/arm/crypto/Kconfig +++ b/arch/arm/crypto/Kconfig @@ -166,7 +166,7 @@ config CRYPTO_NHPOLY1305_NEON config CRYPTO_CURVE25519_NEON tristate "NEON accelerated Curve25519 scalar multiplication library" - depends on KERNEL_MODE_NEON + depends on KERNEL_MODE_NEON && !CPU_BIG_ENDIAN select CRYPTO_LIB_CURVE25519_GENERIC select CRYPTO_ARCH_HAVE_LIB_CURVE25519