From fd16931a2f518a32753920ff20895e5cf04c8ff1 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Sun, 13 Dec 2020 15:39:29 +0100 Subject: [PATCH 1/2] crypto: arm/chacha-neon - add missing counter increment Commit 86cd97ec4b943af3 ("crypto: arm/chacha-neon - optimize for non-block size multiples") refactored the chacha block handling in the glue code in a way that may result in the counter increment to be omitted when calling chacha_block_xor_neon() to process a full block. This violates the skcipher API, which requires that the output IV is suitable for handling more input as long as the preceding input has been presented in round multiples of the block size. Also, the same code is exposed via the chacha library interface whose callers may actually rely on this increment to occur even for final blocks that are smaller than the chacha block size. So increment the counter after calling chacha_block_xor_neon(). Fixes: 86cd97ec4b943af3 ("crypto: arm/chacha-neon - optimize for non-block size multiples") Reported-by: Eric Biggers Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- arch/arm/crypto/chacha-glue.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm/crypto/chacha-glue.c b/arch/arm/crypto/chacha-glue.c index 7b5cf8430c6d..cdde8fd01f8f 100644 --- a/arch/arm/crypto/chacha-glue.c +++ b/arch/arm/crypto/chacha-glue.c @@ -60,6 +60,7 @@ static void chacha_doneon(u32 *state, u8 *dst, const u8 *src, chacha_block_xor_neon(state, d, s, nrounds); if (d != dst) memcpy(dst, buf, bytes); + state[12]++; } } From 0aa171e9b267ce7c52d3a3df7bc9c1fc0203dec5 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Sat, 2 Jan 2021 14:59:09 +0100 Subject: [PATCH 2/2] crypto: ecdh - avoid buffer overflow in ecdh_set_secret() Pavel reports that commit 17858b140bf4 ("crypto: ecdh - avoid unaligned accesses in ecdh_set_secret()") fixes one problem but introduces another: the unconditional memcpy() introduced by that commit may overflow the target buffer if the source data is invalid, which could be the result of intentional tampering. So check params.key_size explicitly against the size of the target buffer before validating the key further. Fixes: 17858b140bf4 ("crypto: ecdh - avoid unaligned accesses in ecdh_set_secret()") Reported-by: Pavel Machek Cc: Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- crypto/ecdh.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/crypto/ecdh.c b/crypto/ecdh.c index d56b8603dec9..96f80c8f8e30 100644 --- a/crypto/ecdh.c +++ b/crypto/ecdh.c @@ -39,7 +39,8 @@ static int ecdh_set_secret(struct crypto_kpp *tfm, const void *buf, struct ecdh params; unsigned int ndigits; - if (crypto_ecdh_decode_key(buf, len, ¶ms) < 0) + if (crypto_ecdh_decode_key(buf, len, ¶ms) < 0 || + params.key_size > sizeof(ctx->private_key)) return -EINVAL; ndigits = ecdh_supported_curve(params.curve_id);