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authorArd Biesheuvel <ardb@kernel.org>2021-01-02 14:59:09 +0100
committerHerbert Xu <herbert@gondor.apana.org.au>2021-01-03 08:35:35 +1100
commit0aa171e9b267ce7c52d3a3df7bc9c1fc0203dec5 (patch)
treef998a01d4f059ea5092a6d370e8d3a8832ec6a73 /crypto
parentfd16931a2f518a32753920ff20895e5cf04c8ff1 (diff)
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 <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>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/ecdh.c3
1 files changed, 2 insertions, 1 deletions
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, &params) < 0)
+ if (crypto_ecdh_decode_key(buf, len, &params) < 0 ||
+ params.key_size > sizeof(ctx->private_key))
return -EINVAL;
ndigits = ecdh_supported_curve(params.curve_id);