X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=crypto%2Fdh_helper.c;h=7f00c771fe8d7cee3bbe3d7921fc137bab4c3d40;hb=b7ac7ece186e66dcaac11c7032017f34bc37b0b2;hp=8ba8a3f826200c611e4e340df4502dab2b112c40;hpb=954e6e03c61d233eae810f8da65270c224fe2fa4;p=mirror_ubuntu-artful-kernel.git

diff --git a/crypto/dh_helper.c b/crypto/dh_helper.c
index 8ba8a3f82620..7f00c771fe8d 100644
--- a/crypto/dh_helper.c
+++ b/crypto/dh_helper.c
@@ -83,6 +83,14 @@ int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params)
 	if (secret.len != crypto_dh_key_len(params))
 		return -EINVAL;
 
+	/*
+	 * Don't permit the buffer for 'key' or 'g' to be larger than 'p', since
+	 * some drivers assume otherwise.
+	 */
+	if (params->key_size > params->p_size ||
+	    params->g_size > params->p_size)
+		return -EINVAL;
+
 	/* Don't allocate memory. Set pointers to data within
 	 * the given buffer
 	 */
@@ -90,6 +98,14 @@ int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params)
 	params->p = (void *)(ptr + params->key_size);
 	params->g = (void *)(ptr + params->key_size + params->p_size);
 
+	/*
+	 * Don't permit 'p' to be 0.  It's not a prime number, and it's subject
+	 * to corner cases such as 'mod 0' being undefined or
+	 * crypto_kpp_maxsize() returning 0.
+	 */
+	if (memchr_inv(params->p, 0, params->p_size) == NULL)
+		return -EINVAL;
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(crypto_dh_decode_key);