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authorArd Biesheuvel <ardb@kernel.org>2021-01-02 14:59:09 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-01-12 20:16:17 +0100
commitff7397add93551647269785a03583aec2ba9f99a (patch)
treebf0c3be01f9e7536d611ddfbe6c185172be46cf7 /crypto/ecdh.c
parent9e60056b1f532520dae5333c24e2e2b944c929b7 (diff)
crypto: ecdh - avoid buffer overflow in ecdh_set_secret()
commit 0aa171e9b267ce7c52d3a3df7bc9c1fc0203dec5 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'crypto/ecdh.c')
-rw-r--r--crypto/ecdh.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/crypto/ecdh.c b/crypto/ecdh.c
index efa4ee72301f..46570b517175 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);