Guard traversers used during parsing against stack overflow
Traversers used during parsing can be vulnerable to stack overflow
since the AST has not yet been validated for max depth. Make sure to
check for traversal depth in traversers used during parsing.
We set the maximum traversal depth in ValidateGlobalInitializer and
ValidateSwitchStatementList to 256, which matches the default value
for validating general AST complexity. The depth check is on
regardless of compiler options. In case the traversers go over the
maximum traversal depth, they fail validation.
BUG=angleproject:2453
TEST=angle_unittests
Change-Id: I89ba576e8ef69663ba35d7b9050a6da319f1757c
Reviewed-on: https://chromium-review.googlesource.com/995795
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>
diff --git a/src/compiler/translator/IsASTDepthBelowLimit.cpp b/src/compiler/translator/IsASTDepthBelowLimit.cpp
index 756c194..73cb9d1 100644
--- a/src/compiler/translator/IsASTDepthBelowLimit.cpp
+++ b/src/compiler/translator/IsASTDepthBelowLimit.cpp
@@ -18,24 +18,10 @@
class MaxDepthTraverser : public TIntermTraverser
{
public:
- MaxDepthTraverser(int depthLimit) : TIntermTraverser(true, true, false), mDepthLimit(depthLimit)
+ MaxDepthTraverser(int depthLimit) : TIntermTraverser(true, false, false, nullptr)
{
+ setMaxAllowedDepth(depthLimit);
}
-
- bool visitBinary(Visit, TIntermBinary *) override { return depthCheck(); }
- bool visitUnary(Visit, TIntermUnary *) override { return depthCheck(); }
- bool visitTernary(Visit, TIntermTernary *) override { return depthCheck(); }
- bool visitSwizzle(Visit, TIntermSwizzle *) override { return depthCheck(); }
- bool visitIfElse(Visit, TIntermIfElse *) override { return depthCheck(); }
- bool visitAggregate(Visit, TIntermAggregate *) override { return depthCheck(); }
- bool visitBlock(Visit, TIntermBlock *) override { return depthCheck(); }
- bool visitLoop(Visit, TIntermLoop *) override { return depthCheck(); }
- bool visitBranch(Visit, TIntermBranch *) override { return depthCheck(); }
-
- protected:
- bool depthCheck() const { return mMaxDepth < mDepthLimit; }
-
- int mDepthLimit;
};
} // anonymous namespace