sdp: Fix buffer overflow

sdp_append_buf shall check if there is enough space to store the data
before copying it.

An independent security researcher, Julian Rauchberger, has reported
this vulnerability to Beyond Security’s SecuriTeam Secure Disclosure
program.

1 files changed, 6 insertions, 0 deletions

diff --git a/lib/sdp.c b/lib/sdp.c
index eb408a948..84311eda1 100644
--- a/lib/sdp.c
+++ b/lib/sdp.c
@@ -2834,6 +2834,12 @@ void sdp_append_to_buf(sdp_buf_t *dst, uint8_t *data, uint32_t len)
 	SDPDBG("Append src size: %d", len);
 	SDPDBG("Append dst size: %d", dst->data_size);
 	SDPDBG("Dst buffer size: %d", dst->buf_size);
+
+	if (dst->data_size + len > dst->buf_size) {
+		SDPERR("Cannot append");
+		return;
+	}
+
 	if (dst->data_size == 0 && dtd == 0) {
 		/* create initial sequence */
 		*p = SDP_SEQ8;