[PATCH 12/12] btmon: fix segfault caused by buffer over-read

[PATCH 12/12] btmon: fix segfault caused by buffer over-read

[Matias Karhumaa]

Fix segfault caused by buffer over-read in service_rsp function of
monitor/sdp.c.

This bug can be triggered locally reading malformed btmon capture file
and also over the air by sending specifically crafted SDP Search
Attribute response to device running btmon.

Bug was found by fuzzing btmon with AFL.
---
 monitor/sdp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/monitor/sdp.c b/monitor/sdp.c
index 13a8807c7..36708f426 100644
--- a/monitor/sdp.c
+++ b/monitor/sdp.c
@@ -585,6 +585,10 @@ static void service_rsp(const struct l2cap_frame *frame, struct tid_data *tid)
 	}
 
 	count = get_be16(frame->data + 2);
+	if (count * 4 > frame->size) {
+		print_text(COLOR_ERROR, "invalid record count");
+                return;
+	}
 
 	print_field("Total record count: %d", get_be16(frame->data));
 	print_field("Current record count: %d", count);
-- 
2.17.1