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| author | Ard Biesheuvel <ardb@kernel.org> | 2021-01-02 14:59:09 +0100 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2021-01-03 08:35:35 +1100 |
| commit | 4204b130b8a4d1cd2c4a0d9a5a09993e8948defe (patch) | |
| tree | 71f7b0fdd4569bb3c045f0fc657d0dba97d2b39a | |
| parent | bc856b9e798dc80d0f0d047b9221c6e1fc27db2b (diff) | |
| download | linux-crypto-4204b130b8a4d1cd2c4a0d9a5a09993e8948defe.tar.gz linux-crypto-4204b130b8a4d1cd2c4a0d9a5a09993e8948defe.zip | |
crypto: ecdh - avoid buffer overflow in ecdh_set_secret()
Pavel reports that commit 8319c80ab523 ("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: 8319c80ab523 ("crypto: ecdh - avoid unaligned accesses in ecdh_set_secret()")
Reported-by: Pavel Machek <pavel@denx.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| -rw-r--r-- | crypto/ecdh.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/crypto/ecdh.c b/crypto/ecdh.c index d56b8603..96f80c8f 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); |