commit 6bc264aee686a8b814e4be1f49e25f1443151c48
author Jamie Madill <jmadill@chromium.org> Sat Mar 31 15:36:05 2018 -0400
committer Commit Bot <commit-bot@chromium.org> Tue Apr 03 17:45:06 2018 +0000
tree ebbbf528ddbcfb199dcea373e75830213a1a5df5
parent 94bbed1e2387130e58b3d59d489343b291129e57

Fix potential bad access in LinkProgram.

This could happen when linking a program with missing attachments
and shaders that have no compiled sources.

Also re-enables the EGL program cache control tests, which were
disabled due to a wrong extension name check.

Bug: chromium:827158
Change-Id: I181f878093c6e3a4acc51552ade8e7c084733a3d
Reviewed-on: https://chromium-review.googlesource.com/989262
Reviewed-by: Luc Ferron <lucferron@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

src/libANGLE/Program.cpp

diff --git a/src/libANGLE/Program.cpp b/src/libANGLE/Program.cpp
index ee934e0..b1080d8 100644
--- a/src/libANGLE/Program.cpp
+++ b/src/libANGLE/Program.cpp
@@ -1049,9 +1049,16 @@
     double startTime = platform->currentTime(platform);
 
     unlink();
+    mInfoLog.reset();
+
+    // Validate we have properly attached shaders before checking the cache.
+    if (!linkValidateShaders(context, mInfoLog))
+    {
+        return NoError();
+    }
 
     ProgramHash programHash;
-    auto *cache = context->getMemoryProgramCache();
+    MemoryProgramCache *cache = context->getMemoryProgramCache();
     if (cache)
     {
         ANGLE_TRY_RESULT(cache->getProgram(context, this, &mState, &programHash), mLinked);
@@ -1068,12 +1075,9 @@
 
     // Cache load failed, fall through to normal linking.
     unlink();
-    mInfoLog.reset();
 
-    if (!linkValidateShaders(context, mInfoLog))
-    {
-        return NoError();
-    }
+    // Re-link shaders after the unlink call.
+    ASSERT(linkValidateShaders(context, mInfoLog));
 
     if (mState.mAttachedComputeShader)
     {
@@ -1284,6 +1288,7 @@
     mValidated = false;
 
     mLinked = false;
+    mInfoLog.reset();
 }
 
 bool Program::isLinked() const