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-rw-r--r--crypto/dh_helper.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/crypto/dh_helper.c b/crypto/dh_helper.c
index 8ba8a3f82620..24fdb2ecaa85 100644
--- a/crypto/dh_helper.c
+++ b/crypto/dh_helper.c
@@ -28,12 +28,12 @@ static inline const u8 *dh_unpack_data(void *dst, const void *src, size_t size)
return src + size;
}
-static inline int dh_data_size(const struct dh *p)
+static inline unsigned int dh_data_size(const struct dh *p)
{
return p->key_size + p->p_size + p->g_size;
}
-int crypto_dh_key_len(const struct dh *p)
+unsigned int crypto_dh_key_len(const struct dh *p)
{
return DH_KPP_SECRET_MIN_SIZE + dh_data_size(p);
}
@@ -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);