From dd2a4edb26e1c78823c50ba10c42f2d3de2e5ec4 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Wed, 21 Oct 2026 22:44:50 -0700 Subject: [PATCH] lib/crypto: mips: Disable Octeon SHA code on little-endian kernels Kernels built for the MIPS64-based Cavium Octeon SoCs are normally big-endian, but little-endian builds are also supported. Currently, the SHA-1, SHA-256, and SHA-512 code using the Octeon crypto co-processor is enabled in both builds. This code is untestable without the hardware. However, based on the code itself, it is implausible that it computes hash values correctly in little-endian builds. Such builds write many incorrect values to COP2: - SHA-1 and SHA-256: The 64-bit integer that contains the last two 32-bit message words of each block is written to COP2 entirely byte-reflected, due to missing endianness conversion in octeon_sha1_start() and octeon_sha256_start() to compensate for using native 64-bit loads from the message bytes. This differs from all the earlier message words which are written correctly. Furthermore, the state is written to COP2 with each 32-bit word byte-reflected within each 64-bit integer, due to incorrect use of 64-bit endianness conversion in write_octeon_64bit_hash_dword() when the state is kept in memory in native-endian 32-bit words. - SHA-512: All the 64-bit message words are written to COP2 byte-reflected, due to missing endianness conversion in write_octeon_64bit_block_sha512() and octeon_sha512_start(). The SHA-512 state words seem to be written correctly. Big-endian kernels aren't affected by these bugs. These bugs also aren't new; this code has been broken on little-endian ever since it and Octeon little-endian support were first added in v4.1. Commit d2a948d2db68 ("MIPS: Octeon: Make octeon-md5 driver endian-agnostic") made the MD5 code work on little-endian kernels by adding 64-bit endianness conversions to the COP2 macros used by MD5 (some of which are shared by SHA-1 and SHA-256, despite those algorithms keeping the state words in native-endian instead of MD5's little-endian, causing some of the strange behavior described above). However, SHA-1, SHA-256, and SHA-512 were never fixed to work on little-endian kernels. Therefore, disable the Octeon SHA-1, SHA-256, and SHA-512 code in little-endian kernels. This causes the generic code that actually computes hash values correctly to be used instead. Fixes: 82be2dcfa6a1 ("crypto: octeon - add SHA1 module") Fixes: c3d0def62001 ("crypto: octeon - add SHA256 module") Fixes: fbaa4dfd51a0 ("crypto: octeon - add SHA512 module") Cc: stable@vger.kernel.org Acked-by: Ard Biesheuvel Link: https://patch.msgid.link/20261022054450.20746-1-ebiggers@kernel.org Signed-off-by: Eric Biggers --- lib/crypto/Kconfig | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig index 56f308dd0273..83b4a211c15d 100644 --- a/lib/crypto/Kconfig +++ b/lib/crypto/Kconfig @@ -237,7 +237,7 @@ config CRYPTO_LIB_SHA1_ARCH depends on CRYPTO_LIB_SHA1 && !UML default y if ARM default y if ARM64 - default y if MIPS && CPU_CAVIUM_OCTEON + default y if MIPS && CPU_CAVIUM_OCTEON && CPU_BIG_ENDIAN default y if PPC default y if S390 default y if SPARC64 @@ -255,7 +255,7 @@ config CRYPTO_LIB_SHA256_ARCH depends on CRYPTO_LIB_SHA256 && !UML default y if ARM && !CPU_V7M default y if ARM64 - default y if MIPS && CPU_CAVIUM_OCTEON + default y if MIPS && CPU_CAVIUM_OCTEON && CPU_BIG_ENDIAN default y if PPC && SPE default y if RISCV && 64BIT && TOOLCHAIN_HAS_VECTOR_CRYPTO && \ RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS @@ -275,7 +275,7 @@ config CRYPTO_LIB_SHA512_ARCH depends on CRYPTO_LIB_SHA512 && !UML default y if ARM && !CPU_V7M default y if ARM64 - default y if MIPS && CPU_CAVIUM_OCTEON + default y if MIPS && CPU_CAVIUM_OCTEON && CPU_BIG_ENDIAN default y if RISCV && 64BIT && TOOLCHAIN_HAS_VECTOR_CRYPTO && \ RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS default y if S390