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authorGonglei <arei.gonglei@huawei.com>2014-05-28 21:21:35 +0800
committerGerd Hoffmann <kraxel@redhat.com>2014-06-02 16:30:52 +0200
commitb52991537c0efe27ee0c1955eb28a4584226d8b5 (patch)
tree7dda35d44b58adf22bb35d8e845dfef961b1c5e7
parent4006617552892a1fe3a5a1f4d103613404abc409 (diff)
downloadfocaccia-qemu-b52991537c0efe27ee0c1955eb28a4584226d8b5.tar.gz
focaccia-qemu-b52991537c0efe27ee0c1955eb28a4584226d8b5.zip
vnc-enc-tight: Fix divide-by-zero in tight_detect_smooth_image{16,24,32}
Spotted by Coverity:

(1) Event assignment:  Assigning: "pixels" = "0".
(2) Event cond_true:  Condition "y < h", taking true branch
(3) Event cond_false:  Condition "x < w", taking false branch
(4) Event loop_end:  Reached end of loop
(5) Event divide_by_zero:  In expression "(stats[0] + stats[1]) * 100U / pixels",
division by expression "pixels" which may be zero has undefined behavior.

290     DEFINE_DETECT_FUNCTION(16)
291     DEFINE_DETECT_FUNCTION(32)

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
-rw-r--r--ui/vnc-enc-tight.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/ui/vnc-enc-tight.c b/ui/vnc-enc-tight.c
index 59b59c0c79..f02352cc46 100644
--- a/ui/vnc-enc-tight.c
+++ b/ui/vnc-enc-tight.c
@@ -181,6 +181,10 @@ tight_detect_smooth_image24(VncState *vs, int w, int h)
         }
     }
 
+    if (pixels == 0) {
+        return 0;
+    }
+
     /* 95% smooth or more ... */
     if (stats[0] * 33 / pixels >= 95) {
         return 0;
@@ -267,7 +271,9 @@ tight_detect_smooth_image24(VncState *vs, int w, int h)
                 y += w;                                                 \
             }                                                           \
         }                                                               \
-                                                                        \
+        if (pixels == 0) {                                              \
+            return 0;                                                   \
+        }                                                               \
         if ((stats[0] + stats[1]) * 100 / pixels >= 90) {               \
             return 0;                                                   \
         }                                                               \