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authorSimon Hausmann <simon.hausmann@digia.com>2013-11-25 09:21:27 +0100
committerThe Qt Project <gerrit-noreply@qt-project.org>2013-11-25 17:34:51 +0100
commitce38c71b1c300f700a9ff004b7c163cc290ecae9 (patch)
treea347b2b4e55e8fb457855f111e5f9cd1921c0a48
parent87da2a2526aa03dd43254730a6e675e83c7c1342 (diff)
Fix out of bounds array access when index is integer and negativev5.2.0-rc1
When the index is a double, the branchTruncateDoubleToUInt takes care of branching when the index is negative, but when it's an integer we need to perform that check ourselves. Without the patch it's rather easy to cause the application to crash. Change-Id: If908923ddc2077b3fb3dd42350f038ff0072e8e1 Reviewed-by: Mitch Curtis <mitch.curtis@digia.com> Reviewed-by: Lars Knoll <lars.knoll@digia.com>
-rw-r--r--src/qml/compiler/qv4isel_masm.cpp13
1 files changed, 11 insertions, 2 deletions
diff --git a/src/qml/compiler/qv4isel_masm.cpp b/src/qml/compiler/qv4isel_masm.cpp
index 9d470c417d..a999dd4da1 100644
--- a/src/qml/compiler/qv4isel_masm.cpp
+++ b/src/qml/compiler/qv4isel_masm.cpp
@@ -1039,10 +1039,13 @@ void InstructionSelection::getElement(V4IR::Expr *base, V4IR::Expr *index, V4IR:
_as->and32(Assembler::TrustedImm32(QV4::Managed::SimpleArray), Assembler::ReturnValueRegister);
Assembler::Jump notSimple = _as->branch32(Assembler::Equal, Assembler::ReturnValueRegister, Assembler::TrustedImm32(0));
+ bool needNegativeCheck = false;
Assembler::Jump fallback, fallback2;
if (tindex->kind == V4IR::Temp::PhysicalRegister) {
if (tindex->type == V4IR::SInt32Type) {
+ fallback = _as->branch32(Assembler::LessThan, (Assembler::RegisterID)tindex->index, Assembler::TrustedImm32(0));
_as->move((Assembler::RegisterID) tindex->index, Assembler::ScratchRegister);
+ needNegativeCheck = true;
} else {
// double, convert and check if it's a int
fallback2 = _as->branchTruncateDoubleToUint32((Assembler::FPRegisterID) tindex->index, Assembler::ScratchRegister);
@@ -1068,13 +1071,17 @@ void InstructionSelection::getElement(V4IR::Expr *base, V4IR::Expr *index, V4IR:
isInteger.link(_as);
_as->or32(Assembler::TrustedImm32(0), Assembler::ScratchRegister);
+ needNegativeCheck = true;
}
// get data, ScratchRegister holds index
addr = _as->loadTempAddress(Assembler::ReturnValueRegister, tbase);
_as->load64(addr, Assembler::ReturnValueRegister);
Address arrayDataLen(Assembler::ReturnValueRegister, qOffsetOf(Object, arrayDataLen));
- Assembler::Jump outOfRange = _as->branch32(Assembler::GreaterThanOrEqual, Assembler::ScratchRegister, arrayDataLen);
+ Assembler::Jump outOfRange;
+ if (needNegativeCheck)
+ outOfRange = _as->branch32(Assembler::LessThan, Assembler::ScratchRegister, Assembler::TrustedImm32(0));
+ Assembler::Jump outOfRange2 = _as->branch32(Assembler::GreaterThanOrEqual, Assembler::ScratchRegister, arrayDataLen);
Address arrayData(Assembler::ReturnValueRegister, qOffsetOf(Object, arrayData));
_as->load64(arrayData, Assembler::ReturnValueRegister);
Q_ASSERT(sizeof(Property) == (1<<4));
@@ -1092,7 +1099,9 @@ void InstructionSelection::getElement(V4IR::Expr *base, V4IR::Expr *index, V4IR:
Assembler::Jump done = _as->jump();
emptyValue.link(_as);
- outOfRange.link(_as);
+ if (outOfRange.isSet())
+ outOfRange.link(_as);
+ outOfRange2.link(_as);
if (fallback.isSet())
fallback.link(_as);
if (fallback2.isSet())