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Diffstat (limited to 'src/corelib/serialization/qdatastream.cpp')
| -rw-r--r-- | src/corelib/serialization/qdatastream.cpp | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/src/corelib/serialization/qdatastream.cpp b/src/corelib/serialization/qdatastream.cpp index fda399512dc..0c2174b9723 100644 --- a/src/corelib/serialization/qdatastream.cpp +++ b/src/corelib/serialization/qdatastream.cpp @@ -164,6 +164,27 @@ QT_BEGIN_NAMESPACE If no full packet is received, this code restores the stream to the initial position, after which you need to wait for more data to arrive. + \section1 Corruption and Security + + QDataStream is not resilient against corrupted data inputs and should + therefore not be used for security-sensitive situations, even when using + transactions. Transactions will help determine if a valid input can + currently be decoded with the data currently available on an asynchronous + device, but will assume that the data that is available is correctly + formed. + + Additionally, many QDataStream demarshalling operators will allocate memory + based on information found in the stream. Those operators perform no + verification on whether the requested amount of memory is reasonable or if + it is compatible with the amount of data available in the stream (example: + demarshalling a QByteArray or QString may see the request for allocation of + several gigabytes of data). + + QDataStream should not be used on content whose provenance cannot be + trusted. Applications should be designed to attempt to decode only streams + whose provenance is at least as trustworthy as that of the application + itself or its plugins. + \sa QTextStream, QVariant */ |