Details
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Bug
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Resolution: Unresolved
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P2: Important
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None
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5.12.10
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None
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All
Description
build qt with enabled ubsan.
Launch wayland compositor examples.
ubsan reports sub overflow in qrect.h on code:
Q_DECL_CONSTEXPR inline int QRect::width() const Q_DECL_NOTHROW { return x2 - x1 + 1; }
The reason of overflow is next code in file qwaylandsurface.cpp:
static QRegion infiniteRegion() { return QRegion(QRect(QPoint(std::numeric_limits<int>::min(), std::numeric_limits<int>::min()), QPoint(std::numeric_limits<int>::max(), std::numeric_limits<int>::max()))); }
as you can see, with()function will calculate
INT_MAX - INT_MIN +1;
this is real overflow.
I checked on master:
it is also has this issue.