Fix #3950: Div by 0 during DXT4 DDS load

Signed-off-by: Jesse Yurkovich <[email protected]>
AcademySoftwareFoundation · Aug 24, 2023 · 64c1495 · 64c1495
1 parent 56c734a
commit 64c1495
Show file tree

Hide file tree

Showing 4 changed files with 15 additions and 6 deletions.
diff --git a/src/dds.imageio/ddsinput.cpp b/src/dds.imageio/ddsinput.cpp
@@ -789,12 +789,14 @@ DDSInput::internal_readimg(unsigned char* dst, int w, int h, int d)
             for (int y = 0; y < h; y++) {
                 for (int x = 0; x < w; x++) {
                     k          = (y * w + x) * 4;
-                    dst[k + 0] = (unsigned char)((int)dst[k + 0] * 255
-                                                 / (int)dst[k + 3]);
-                    dst[k + 1] = (unsigned char)((int)dst[k + 1] * 255
-                                                 / (int)dst[k + 3]);
-                    dst[k + 2] = (unsigned char)((int)dst[k + 2] * 255
-                                                 / (int)dst[k + 3]);
+                    if (dst[k + 3]) {
+                        dst[k + 0] = (unsigned char)((int)dst[k + 0] * 255
+                                                     / (int)dst[k + 3]);
+                        dst[k + 1] = (unsigned char)((int)dst[k + 1] * 255
+                                                     / (int)dst[k + 3]);
+                        dst[k + 2] = (unsigned char)((int)dst[k + 2] * 255
+                                                     / (int)dst[k + 3]);
+                    }
                 }
             }
         }

diff --git a/testsuite/dds/ref/out.txt b/testsuite/dds/ref/out.txt
@@ -208,3 +208,9 @@ src/crash-1634.dds   :   16 x    8, 1 channel, uint8 dds
 oiiotool ERROR: read : "src/crash-1635.dds": Unsupported DDS bit depth: 1048576 (maybe it's a corrupted file?)
 Full command line was:
 > oiiotool --info -v -a --hash src/crash-1635.dds
+Reading src/crash-3950.dds
+src/crash-3950.dds   :   16 x    1, 3 channel, uint8 dds
+    SHA-1: 430EFD5F1F3B2D6D48D10C3836D8FD4C83CA47C7
+    channel list: R, G, B
+    compression: "DXT4"
+    textureformat: "Plain Texture"
diff --git a/testsuite/dds/run.py b/testsuite/dds/run.py
@@ -51,3 +51,4 @@
 # Test more corrupted files or those that used to crash
 command += info_command ("src/crash-1634.dds", hash=True)
 command += info_command ("src/crash-1635.dds", hash=True)
+command += info_command ("src/crash-3950.dds", hash=True)
diff --git a/testsuite/dds/src/crash-3950.dds b/testsuite/dds/src/crash-3950.dds