From 56978d25f4e585bfd4b7f05526f4d62f51a188c8 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Thu, 14 Mar 2019 22:57:51 +0800 Subject: [PATCH] crypto: arm64/crct10dif - revert to C code for short inputs mainline inclusion from mainline-5.0 commit d72b9d4acd54 category: bugfix bugzilla: 11173 CVE: NA ------------------------------------------------- The SIMD routine ported from x86 used to have a special code path for inputs < 16 bytes, which got lost somewhere along the way. Instead, the current glue code aligns the input pointer to 16 bytes, which is not really necessary on this architecture (although it could be beneficial to performance to expose aligned data to the the NEON routine), but this could result in inputs of less than 16 bytes to be passed in. This not only fails the new extended tests that Eric has implemented, it also results in the code reading past the end of the input, which could potentially result in crashes when dealing with less than 16 bytes of input at the end of a page which is followed by an unmapped page. So update the glue code to only invoke the NEON routine if the input is at least 16 bytes. Reported-by: Eric Biggers Reviewed-by: Eric Biggers Fixes: 6ef5737f3931 ("crypto: arm64/crct10dif - port x86 SSE implementation to arm64") Cc: # v4.10+ Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu Signed-off-by: Chen Zhou Reviewed-by: Yang Yingliang Signed-off-by: Yang Yingliang --- arch/arm64/crypto/crct10dif-ce-glue.c | 25 ++++++------------------- 1 file changed, 6 insertions(+), 19 deletions(-) diff --git a/arch/arm64/crypto/crct10dif-ce-glue.c b/arch/arm64/crypto/crct10dif-ce-glue.c index 96f0cae4a022..617bcfc1b080 100644 --- a/arch/arm64/crypto/crct10dif-ce-glue.c +++ b/arch/arm64/crypto/crct10dif-ce-glue.c @@ -36,26 +36,13 @@ static int crct10dif_update(struct shash_desc *desc, const u8 *data, unsigned int length) { u16 *crc = shash_desc_ctx(desc); - unsigned int l; - if (unlikely((u64)data % CRC_T10DIF_PMULL_CHUNK_SIZE)) { - l = min_t(u32, length, CRC_T10DIF_PMULL_CHUNK_SIZE - - ((u64)data % CRC_T10DIF_PMULL_CHUNK_SIZE)); - - *crc = crc_t10dif_generic(*crc, data, l); - - length -= l; - data += l; - } - - if (length > 0) { - if (may_use_simd()) { - kernel_neon_begin(); - *crc = crc_t10dif_pmull(*crc, data, length); - kernel_neon_end(); - } else { - *crc = crc_t10dif_generic(*crc, data, length); - } + if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && may_use_simd()) { + kernel_neon_begin(); + *crc = crc_t10dif_pmull(*crc, data, length); + kernel_neon_end(); + } else { + *crc = crc_t10dif_generic(*crc, data, length); } return 0; -- GitLab