From 82304e12695dd5732839a649f15eaa4ce08abfe5 Mon Sep 17 00:00:00 2001 From: John Stiles Date: Thu, 13 Apr 2023 17:58:24 -0400 Subject: [Backport] CVE-2023-2136: Integer overflow in Skia (2/2) Cherry-pick of patch originally reviewed on https://skia-review.googlesource.com/c/skia/+/673577: Enforce size limits on struct and array declarations. M108 merge issues: resources/sksl/BUILD.bazel: File doesn't exist in M108, tests are added manually to gn/sksl_tests.gni. gn/sksl_tests.gni: Conflicting rts entries tests/sksl/shared/Ossfuzz37900.* Not present in 108, skipped. src/sksl/ir/SkSLType.cpp: - Conflicting includes - MakeStructType(): - Conflicting function signature - context isn't a parameter, used ThreadContext::Context() directly. This improves error reporting by more clearly attaching the error message to the oversized type. Bug: chromium:1432603 Change-Id: I26511f08aff22072cf4913abf7be2c49940a732c Reviewed-on: https://skia-review.googlesource.com/c/skia/+/671377 Commit-Queue: John Stiles (cherry picked from commit 1cbd33ecd73523f8d4bf88e9c5576303b39e5556) Reviewed-on: https://skia-review.googlesource.com/c/skia/+/673577 Reviewed-by: John Stiles Reviewed-on: https://codereview.qt-project.org/c/qt/qtwebengine-chromium/+/474619 Reviewed-by: Allan Sandfeld Jensen --- chromium/third_party/skia/src/sksl/dsl/DSLType.cpp | 4 ++-- chromium/third_party/skia/src/sksl/ir/SkSLType.cpp | 20 +++++++++++++++++--- 2 files changed, 19 insertions(+), 5 deletions(-) diff --git a/chromium/third_party/skia/src/sksl/dsl/DSLType.cpp b/chromium/third_party/skia/src/sksl/dsl/DSLType.cpp index 5648c51c92b..aacdfb00052 100644 --- a/chromium/third_party/skia/src/sksl/dsl/DSLType.cpp +++ b/chromium/third_party/skia/src/sksl/dsl/DSLType.cpp @@ -266,7 +266,7 @@ DSLExpression DSLType::Construct(DSLType type, SkSpan argArray) { DSLType Array(const DSLType& base, int count, Position pos) { count = base.skslType().convertArraySize(ThreadContext::Context(), pos, - DSLExpression(count, pos).release()); + DSLExpression(count, pos).release()); if (!count) { return DSLType(kPoison_Type); } @@ -278,7 +278,7 @@ DSLType UnsizedArray(const DSLType& base, Position pos) { return DSLType(kPoison_Type); } return ThreadContext::SymbolTable()->addArrayDimension(&base.skslType(), - SkSL::Type::kUnsizedArray); + SkSL::Type::kUnsizedArray); } DSLType Struct(std::string_view name, SkSpan fields, Position pos) { diff --git a/chromium/third_party/skia/src/sksl/ir/SkSLType.cpp b/chromium/third_party/skia/src/sksl/ir/SkSLType.cpp index 04c1946509e..c474db149f5 100644 --- a/chromium/third_party/skia/src/sksl/ir/SkSLType.cpp +++ b/chromium/third_party/skia/src/sksl/ir/SkSLType.cpp @@ -12,10 +12,12 @@ #include "include/private/SkTFitsIn.h" #include "include/sksl/SkSLErrorReporter.h" #include "src/core/SkMathPriv.h" +#include "src/core/SkSafeMath.h" #include "src/sksl/SkSLBuiltinTypes.h" #include "src/sksl/SkSLConstantFolder.h" #include "src/sksl/SkSLContext.h" #include "src/sksl/SkSLProgramSettings.h" +#include "src/sksl/SkSLThreadContext.h" #include "src/sksl/ir/SkSLConstructorArrayCast.h" #include "src/sksl/ir/SkSLConstructorCompoundCast.h" #include "src/sksl/ir/SkSLConstructorScalarCast.h" @@ -648,6 +650,17 @@ std::unique_ptr Type::MakeScalarType(std::string_view name, const char* ab std::unique_ptr Type::MakeStructType(Position pos, std::string_view name, std::vector fields, bool interfaceBlock) { + size_t slots = 0; + for (const Field& field : fields) { + if (field.fType->isUnsizedArray()) { + continue; + } + slots = SkSafeMath::Add(slots, field.fType->slotCount()); + if (slots >= kVariableSlotLimit) { + ThreadContext::Context().fErrors->error(pos, "struct is too large"); + break; + } + } return std::make_unique(pos, name, std::move(fields), interfaceBlock); } @@ -1120,8 +1133,9 @@ bool Type::checkIfUsableInArray(const Context& context, Position arrayPos) const return true; } -SKSL_INT Type::convertArraySize(const Context& context, Position arrayPos, - std::unique_ptr size) const { +SKSL_INT Type::convertArraySize(const Context& context, + Position arrayPos, + std::unique_ptr size) const { size = context.fTypes.fInt->coerceExpression(std::move(size), context); if (!size) { return 0; @@ -1138,7 +1152,7 @@ SKSL_INT Type::convertArraySize(const Context& context, Position arrayPos, context.fErrors->error(size->fPosition, "array size must be positive"); return 0; } - if (!SkTFitsIn(count)) { + if (SkSafeMath::Mul(this->slotCount(), count) > kVariableSlotLimit) { context.fErrors->error(size->fPosition, "array size is too large"); return 0; } -- cgit v1.2.1