From b82457eaa658153449d9eab728b19927311e88db Mon Sep 17 00:00:00 2001 From: Andrew Tridgell Date: Sun, 27 Jul 2014 21:14:47 +1000 Subject: [PATCH] FollowMe: avoid integer underflow in mavlink txspace check --- FollowMe/simplegcs.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/FollowMe/simplegcs.cpp b/FollowMe/simplegcs.cpp index 2c2c25fe0f..8b3dafab5d 100644 --- a/FollowMe/simplegcs.cpp +++ b/FollowMe/simplegcs.cpp @@ -65,8 +65,8 @@ void simplegcs_send_heartbeat(mavlink_channel_t chan) { bool simplegcs_try_send_statustext(mavlink_channel_t chan, const char *text, int len) { - int payload_space = comm_get_txspace(chan) - MAVLINK_NUM_NON_PAYLOAD_BYTES; - if (payload_space < MAVLINK_MSG_ID_STATUSTEXT_LEN) return false; + uint16_t txspace = comm_get_txspace(chan); + if (payload_space < MAVLINK_MSG_ID_STATUSTEXT_LEN+MAVLINK_NUM_NON_PAYLOAD_BYTES) return false; char statustext[50] = { 0 }; if (len < 50) {