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[scudo] Double frees result in chunk state error #110345

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Merged
merged 3 commits into from
Oct 16, 2024
Merged

[scudo] Double frees result in chunk state error #110345

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[scudo] Double frees result in chunk state error
cferris1000 Sep 27, 2024
b264a88
Move comment closer to usage.
cferris1000 Sep 28, 2024
87a21c3
Update from comments.
cferris1000 Sep 30, 2024
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23 changes: 14 additions & 9 deletions compiler-rt/lib/scudo/standalone/combined.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1252,22 +1252,25 @@ class Allocator {
else
Header->State = Chunk::State::Quarantined;

void *BlockBegin;
if (LIKELY(!useMemoryTagging<AllocatorConfig>(Options))) {
if (LIKELY(!useMemoryTagging<AllocatorConfig>(Options)))
Header->OriginOrWasZeroed = 0U;
if (BypassQuarantine && allocatorSupportsMemoryTagging<AllocatorConfig>())
Ptr = untagPointer(Ptr);
BlockBegin = getBlockBegin(Ptr, Header);
} else {
else
Header->OriginOrWasZeroed =
Header->ClassId && !TSDRegistry.getDisableMemInit();
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@ChiaHungDuan ChiaHungDuan Sep 30, 2024

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Small nit:

It's a multiple lines statement so I would add brackets here

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@cferris1000 cferris1000 Sep 30, 2024

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Done.

BlockBegin =
retagBlock(Options, TaggedPtr, Ptr, Header, Size, BypassQuarantine);
}

Chunk::storeHeader(Cookie, Ptr, Header);

if (BypassQuarantine) {
void *BlockBegin;
if (LIKELY(!useMemoryTagging<AllocatorConfig>(Options))) {
// Must do this after storeHeader because loadHeader uses a tagged ptr.
if (allocatorSupportsMemoryTagging<AllocatorConfig>())
Ptr = untagPointer(Ptr);
BlockBegin = getBlockBegin(Ptr, Header);
} else {
BlockBegin = retagBlock(Options, TaggedPtr, Ptr, Header, Size, true);
}

const uptr ClassId = Header->ClassId;
if (LIKELY(ClassId)) {
bool CacheDrained;
Expand All @@ -1285,6 +1288,8 @@ class Allocator {
Secondary.deallocate(Options, BlockBegin);
}
} else {
if (UNLIKELY(useMemoryTagging<AllocatorConfig>(Options)))
retagBlock(Options, TaggedPtr, Ptr, Header, Size, false);
typename TSDRegistryT::ScopedTSD TSD(TSDRegistry);
Quarantine.put(&TSD->getQuarantineCache(),
QuarantineCallback(*this, TSD->getCache()), Ptr, Size);
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21 changes: 21 additions & 0 deletions compiler-rt/lib/scudo/standalone/tests/combined_test.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -534,6 +534,27 @@ SCUDO_TYPED_TEST(ScudoCombinedDeathTest, UseAfterFree) {
}
}

SCUDO_TYPED_TEST(ScudoCombinedDeathTest, DoubleFreeFromPrimary) {
auto *Allocator = this->Allocator.get();

for (scudo::uptr SizeLog = 0U; SizeLog <= 20U; SizeLog++) {
const scudo::uptr Size = 1U << SizeLog;
if (!isPrimaryAllocation<TestAllocator<TypeParam>>(Size, 0))
break;

// Verify that a double free results in a chunk state error.
EXPECT_DEATH(
{
// Allocate from primary
void *P = Allocator->allocate(Size, Origin);
ASSERT_TRUE(P != nullptr);
Allocator->deallocate(P, Origin);
Allocator->deallocate(P, Origin);
},
"invalid chunk state");
}
}

SCUDO_TYPED_TEST(ScudoCombinedDeathTest, DisableMemoryTagging) {
auto *Allocator = this->Allocator.get();

Expand Down