This is a note to let you know that I've just added the patch titled crypto: ecdh_helper - Ensure 'len >= secret.len' in decode_key() to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: crypto-ecdh_helper-ensure-len-secret.len-in-decode_k.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 35f9f257a30f0fb5074a4ed455e01daa55310790 Author: Daniele Alessandrelli <daniele.alessandrelli@xxxxxxxxx> Date: Wed Feb 3 11:28:37 2021 +0000 crypto: ecdh_helper - Ensure 'len >= secret.len' in decode_key() [ Upstream commit a53ab94eb6850c3657392e2d2ce9b38c387a2633 ] The length ('len' parameter) passed to crypto_ecdh_decode_key() is never checked against the length encoded in the passed buffer ('buf' parameter). This could lead to an out-of-bounds access when the passed length is less than the encoded length. Add a check to prevent that. Fixes: 3c4b23901a0c7 ("crypto: ecdh - Add ECDH software support") Signed-off-by: Daniele Alessandrelli <daniele.alessandrelli@xxxxxxxxx> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/crypto/ecdh_helper.c b/crypto/ecdh_helper.c index 66fcb2ea81544..fca63b559f655 100644 --- a/crypto/ecdh_helper.c +++ b/crypto/ecdh_helper.c @@ -67,6 +67,9 @@ int crypto_ecdh_decode_key(const char *buf, unsigned int len, if (secret.type != CRYPTO_KPP_SECRET_TYPE_ECDH) return -EINVAL; + if (unlikely(len < secret.len)) + return -EINVAL; + ptr = ecdh_unpack_data(¶ms->curve_id, ptr, sizeof(params->curve_id)); ptr = ecdh_unpack_data(¶ms->key_size, ptr, sizeof(params->key_size)); if (secret.len != crypto_ecdh_key_len(params))