From 1ace2d21f92cd9f8b09ab974ef9abf5c89463ea0 Mon Sep 17 00:00:00 2001 From: Marc Mutz Date: Wed, 7 Sep 2022 16:47:49 +0200 Subject: [PATCH] qUncompress: use existing MaxByteArraySize MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ... instead of rolling your own. Since MaxByteArraySize already adjusts for the trailing NUL byte in QByteArray, the odd 'len >= max' now become a more natural 'len > max'. Rename the limit variable to MaxDecompressedSize, which is more specific, and remove comments that now look out of place. As a drive-by, re-arrange an else branch that, had it stayed, would have required an adjusted if branch to require braces around a single-line statement. Task-number: QTBUG-104972 Change-Id: I6805dab8391b7e51db30d99b1b8968434062d12d Reviewed-by: Thiago Macieira Reviewed-by: Qt CI Bot (cherry picked from commit b84f4be6b78feec617b8d97b00a8231c15d83f67) Reviewed-by: Mårten Nordheim --- src/corelib/text/qbytearray.cpp | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) diff --git a/src/corelib/text/qbytearray.cpp b/src/corelib/text/qbytearray.cpp index a3aecd282c6..c3342616589 100644 --- a/src/corelib/text/qbytearray.cpp +++ b/src/corelib/text/qbytearray.cpp @@ -632,11 +632,9 @@ QByteArray qUncompress(const uchar* data, qsizetype nbytes) size_t expectedSize = size_t((data[0] << 24) | (data[1] << 16) | (data[2] << 8) | (data[3] )); size_t len = qMax(expectedSize, 1ul); - constexpr size_t maxPossibleSize = MaxAllocSize - sizeof(QByteArray::Data); - if (len >= maxPossibleSize) { - // QByteArray does not support that huge size anyway. + constexpr size_t MaxDecompressedSize = size_t(MaxByteArraySize); + if (len > MaxDecompressedSize) return invalidCompressedData(); - } Q_ASSERT(len <= size_t((std::numeric_limits::max)())); QByteArray::DataPointer d(QByteArray::Data::allocate(qsizetype(len))); @@ -662,18 +660,16 @@ QByteArray qUncompress(const uchar* data, qsizetype nbytes) return QByteArray(); case Z_BUF_ERROR: - static_assert(maxPossibleSize <= (std::numeric_limits::max)() / 2, + static_assert(MaxDecompressedSize <= (std::numeric_limits::max)() / 2, "oops, next line may overflow"); len *= 2; - if (len >= maxPossibleSize) { - // QByteArray does not support that huge size anyway. + if (len > MaxDecompressedSize) return invalidCompressedData(); - } else { - // grow the block - d->reallocate(d->allocatedCapacity()*2, QArrayData::Grow); - if (d.data() == nullptr) // reallocation failed - return invalidCompressedData(); - } + + d->reallocate(d->allocatedCapacity() * 2, QArrayData::Grow); + if (d.data() == nullptr) // reallocation failed + return invalidCompressedData(); + continue; case Z_DATA_ERROR: