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Unified Diff: src/zone.cc

Issue 1930873002: Fix overflow issue in Zone::New (Closed) Base URL: https://chromium.googlesource.com/v8/v8.git@master
Patch Set: windows likes casts Created 4 years, 8 months ago
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Index: src/zone.cc
diff --git a/src/zone.cc b/src/zone.cc
index 461ee73745de5ebcaf8caf295e12e89854d65f86..a10b63612e484962870ab2004c6bf2a7ff44f49a 100644
--- a/src/zone.cc
+++ b/src/zone.cc
@@ -104,7 +104,10 @@ void* Zone::New(size_t size) {
Address result = position_;
const size_t size_with_redzone = size + kASanRedzoneBytes;
- if (limit_ < position_ + size_with_redzone) {
+ const uintptr_t limit = reinterpret_cast<uintptr_t>(limit_);
+ const uintptr_t position = reinterpret_cast<uintptr_t>(position_);
+ // position_ > limit_ can be true after the alignment correction above.
+ if (limit < position || size_with_redzone > limit - position) {
result = NewExpand(size_with_redzone);
} else {
position_ += size_with_redzone;
@@ -221,7 +224,10 @@ Address Zone::NewExpand(size_t size) {
// Make sure the requested size is already properly aligned and that
// there isn't enough room in the Zone to satisfy the request.
DCHECK_EQ(size, RoundDown(size, kAlignment));
- DCHECK_LT(limit_, position_ + size);
+ DCHECK(limit_ < position_ ||
+ reinterpret_cast<uintptr_t>(limit_) -
+ reinterpret_cast<uintptr_t>(position_) <
+ size);
// Compute the new segment size. We use a 'high water mark'
// strategy, where we increase the segment size every time we expand
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