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[Backport] CVE-2021-30513: Type Confusion in V8
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Cherry-pick of commit originally reviewed on
https://chromium-review.googlesource.com/c/v8/v8/+/2883780:
Reland "[compiler] Fix more truncation bugs in SimplifiedLowering"

This is a reland of 47077d94492cb604e3a7f02c0d7c3c495ff6b713 without
changes. The revert was false alarm.

[M86]: Resolved simple conflicts.

Original change's description:
> [compiler] Fix more truncation bugs in SimplifiedLowering
>
> Bug: chromium:1200490
> Change-Id: I3555b6d99bdb4b4e7c302a43a82c17e8bff84ebe
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2840452
> Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
> Commit-Queue: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#74097}

(cherry picked from commit e4a580c9104e42968e8e13b8c7d933f0b2eda2a3)

(cherry picked from commit 97ad04543438f7b235b21346fdd198f81028cd5e)

Bug: chromium:1200490
Tbr: nicohartmann@chromium.org
No-Try: true
No-Presubmit: true
No-Tree-Checks: true
Change-Id: Iedddcf2d0117fa59dc9d7a3604ef203808ad2903
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Original-Commit-Position: refs/branch-heads/9.0@{#47}
Cr-Original-Branched-From: bd0108b4c88e0d6f2350cb79b5f363fbd02f3eb7-refs/heads/9.0.257@{#1}
Cr-Original-Branched-From: 349bcc6a075411f1a7ce2d866c3dfeefc2efa39d-refs/heads/master@{#73001}
Reviewed-by: Jana Grill <janagrill@google.com>
Commit-Queue: Victor-Gabriel Savu <vsavu@google.com>
Cr-Commit-Position: refs/branch-heads/8.6@{#95}
Cr-Branched-From: a64aed2333abf49e494d2a5ce24bbd14fff19f60-refs/heads/8.6.395@{#1}
Cr-Branched-From: a626bc036236c9bf92ac7b87dc40c9e538b087e3-refs/heads/master@{#69472}
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
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@GeorgNeis @mibrunin
GeorgNeis authored and mibrunin committed May 26, 2021
1 parent a7025fe commit 59c82b5
Showing 1 changed file with 43 additions and 26 deletions.
69 changes: 43 additions & 26 deletions chromium/v8/src/compiler/simplified-lowering.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -1398,17 +1398,32 @@ class RepresentationSelector {
return jsgraph_->simplified();
}

void LowerToCheckedInt32Mul(Node* node, Truncation truncation,
Type input0_type, Type input1_type) {
// If one of the inputs is positive and/or truncation is being applied,
// there is no need to return -0.
CheckForMinusZeroMode mz_mode =
truncation.IdentifiesZeroAndMinusZero() ||
IsSomePositiveOrderedNumber(input0_type) ||
IsSomePositiveOrderedNumber(input1_type)
? CheckForMinusZeroMode::kDontCheckForMinusZero
: CheckForMinusZeroMode::kCheckForMinusZero;
NodeProperties::ChangeOp(node, simplified()->CheckedInt32Mul(mz_mode));
template <Phase T>
void VisitForCheckedInt32Mul(Node* node, Truncation truncation,
Type input0_type, Type input1_type,
UseInfo input_use) {
DCHECK_EQ(node->opcode(), IrOpcode::kSpeculativeNumberMultiply);
// A -0 input is impossible or will cause a deopt.
DCHECK(BothInputsAre(node, Type::Signed32()) ||
!input_use.truncation().IdentifiesZeroAndMinusZero());

CheckForMinusZeroMode mz_mode;
Type restriction;
if (IsSomePositiveOrderedNumber(input0_type) ||
IsSomePositiveOrderedNumber(input1_type)) {
mz_mode = CheckForMinusZeroMode::kDontCheckForMinusZero;
restriction = Type::Signed32();
} else if (truncation.IdentifiesZeroAndMinusZero()) {
mz_mode = CheckForMinusZeroMode::kDontCheckForMinusZero;
restriction = Type::Signed32OrMinusZero();
} else {
mz_mode = CheckForMinusZeroMode::kCheckForMinusZero;
restriction = Type::Signed32();
}

VisitBinop<T>(node, input_use, MachineRepresentation::kWord32, restriction);
if (lower<T>())
NodeProperties::ChangeOp(node, simplified()->CheckedInt32Mul(mz_mode));
}

void ChangeToInt32OverflowOp(Node* node) {
Expand Down Expand Up @@ -1600,12 +1615,22 @@ class RepresentationSelector {
VisitBinop<T>(node, lhs_use, rhs_use, MachineRepresentation::kWord32);
if (lower<T>()) DeferReplacement(node, lowering->Int32Mod(node));
} else if (BothInputsAre(node, Type::Unsigned32OrMinusZeroOrNaN())) {
Type const restriction =
truncation.IdentifiesZeroAndMinusZero() &&
TypeOf(node->InputAt(0)).Maybe(Type::MinusZero())
? Type::Unsigned32OrMinusZero()
: Type::Unsigned32();
VisitBinop<T>(node, lhs_use, rhs_use, MachineRepresentation::kWord32,
Type::Unsigned32());
restriction);
if (lower<T>()) ChangeToUint32OverflowOp(node);
} else {
Type const restriction =
truncation.IdentifiesZeroAndMinusZero() &&
TypeOf(node->InputAt(0)).Maybe(Type::MinusZero())
? Type::Signed32OrMinusZero()
: Type::Signed32();
VisitBinop<T>(node, lhs_use, rhs_use, MachineRepresentation::kWord32,
Type::Signed32());
restriction);
if (lower<T>()) ChangeToInt32OverflowOp(node);
}
return;
Expand Down Expand Up @@ -2165,23 +2190,17 @@ class RepresentationSelector {
// If both inputs and feedback are int32, use the overflow op.
if (hint == NumberOperationHint::kSignedSmall ||
hint == NumberOperationHint::kSigned32) {
VisitBinop<T>(node, UseInfo::TruncatingWord32(),
MachineRepresentation::kWord32, Type::Signed32());
if (lower<T>()) {
LowerToCheckedInt32Mul(node, truncation, input0_type,
input1_type);
}
VisitForCheckedInt32Mul<T>(node, truncation, input0_type,
input1_type,
UseInfo::TruncatingWord32());
return;
}
}

if (hint == NumberOperationHint::kSignedSmall ||
hint == NumberOperationHint::kSigned32) {
VisitBinop<T>(node, CheckedUseInfoAsWord32FromHint(hint),
MachineRepresentation::kWord32, Type::Signed32());
if (lower<T>()) {
LowerToCheckedInt32Mul(node, truncation, input0_type, input1_type);
}
VisitForCheckedInt32Mul<T>(node, truncation, input0_type, input1_type,
CheckedUseInfoAsWord32FromHint(hint));
return;
}

Expand Down Expand Up @@ -3901,7 +3920,6 @@ template <>
void RepresentationSelector::SetOutput<RETYPE>(
Node* node, MachineRepresentation representation, Type restriction_type) {
NodeInfo* const info = GetInfo(node);
DCHECK(info->restriction_type().Is(restriction_type));
DCHECK(restriction_type.Is(info->restriction_type()));
info->set_output(representation);
}
Expand All @@ -3911,7 +3929,6 @@ void RepresentationSelector::SetOutput<LOWER>(
Node* node, MachineRepresentation representation, Type restriction_type) {
NodeInfo* const info = GetInfo(node);
DCHECK_EQ(info->representation(), representation);
DCHECK(info->restriction_type().Is(restriction_type));
DCHECK(restriction_type.Is(info->restriction_type()));
USE(info);
}
Expand Down

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