Make sure we can read QXLPathSeg structures

start pointer points to a QXLPathSeg structure.
Before reading from the structure, make sure the structure is contained
in the memory range checked.

Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
Acked-by: Christophe Fergeau <cfergeau@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/server/red_parse_qxl.c b/server/red_parse_qxl.c
index f21bfa55..281faad6 100644
--- a/server/red_parse_qxl.c
+++ b/server/red_parse_qxl.c
@@ -256,7 +256,7 @@ static SpicePath *red_get_path(RedMemSlotInfo *slots, int group_id,
 
     start = (QXLPathSeg*)data;
     end = (QXLPathSeg*)(data + size);
-    while (start < end) {
+    while (start+1 < end) {
         n_segments++;
         count = start->count;
         segment_size = sizeof(SpicePathSeg) + count * sizeof(SpicePointFix);
@@ -272,7 +272,7 @@ static SpicePath *red_get_path(RedMemSlotInfo *slots, int group_id,
     seg = (SpicePathSeg*)&red->segments[n_segments];
     n_segments = 0;
     mem_size2 = sizeof(*red);
-    while (start < end) {
+    while (start+1 < end) {
         red->segments[n_segments++] = seg;
         count = start->count;