From d2c0fc2b5f1c07c1e0acb1c0127578066b6f9b8e Mon Sep 17 00:00:00 2001 From: Edward Welbourne Date: Tue, 24 Nov 2020 12:45:11 +0100 Subject: [PATCH] Bounds-check time-zone offsets when parsing Parsing of time-zone offsets should check the offset string conforms to the expected format and has valid values in its fields. The QDateTime parser, fromOffsetString(), neglected the bounds check on hours; the QTzTimeZonePrivate parser, parsePosixTime(), neglected all upper bounds checks, only checking against negative valus. Drive-by - refined phrasing of a comment. Fixes: QTBUG-88656 Change-Id: If04cdbe65064108eaa87c42310527783ad21b4c0 Reviewed-by: Thiago Macieira (cherry picked from commit 380d97e1bd15e753907c378a070bdf7f1c1cf06e) Reviewed-by: Edward Welbourne --- src/corelib/time/qdatetime.cpp | 2 +- src/corelib/time/qtimezoneprivate_tz.cpp | 27 ++++++++++++++++----------- 2 files changed, 17 insertions(+), 12 deletions(-) diff --git a/src/corelib/time/qdatetime.cpp b/src/corelib/time/qdatetime.cpp index e824787880c..a2816e87f4a 100644 --- a/src/corelib/time/qdatetime.cpp +++ b/src/corelib/time/qdatetime.cpp @@ -240,7 +240,7 @@ static int fromOffsetString(QStringView offsetString, bool *valid) noexcept const QStringView hhRef = time.left(qMin(hhLen, time.size())); bool ok = false; const int hour = C.toInt(hhRef, &ok); - if (!ok) + if (!ok || hour > 23) // More generous than QTimeZone::MaxUtcOffsetSecs return 0; const QStringView mmRef = time.mid(qMin(mmIndex, time.size())); diff --git a/src/corelib/time/qtimezoneprivate_tz.cpp b/src/corelib/time/qtimezoneprivate_tz.cpp index b816b4ecff2..adc590878d7 100644 --- a/src/corelib/time/qtimezoneprivate_tz.cpp +++ b/src/corelib/time/qtimezoneprivate_tz.cpp @@ -394,29 +394,34 @@ static int parsePosixTime(const char *begin, const char *end) // Format "hh[:mm[:ss]]" int hour, min = 0, sec = 0; - // Note that the calls to qstrtoll do *not* check the end pointer, which - // means they proceed until they find a non-digit. We check that we're - // still in range at the end, but we may have read from past end. It's the - // caller's responsibility to ensure that begin is part of a - // null-terminated string. + // Note that the calls to qstrtoll do *not* check against the end pointer, + // which means they proceed until they find a non-digit. We check that we're + // still in range at the end, but we may have read past end. It's the + // caller's responsibility to ensure that begin is part of a null-terminated + // string. + const int maxHour = QTimeZone::MaxUtcOffsetSecs / 3600; bool ok = false; - hour = qstrtoll(begin, &begin, 10, &ok); - if (!ok || hour < 0) + const char *cut = begin; + hour = qstrtoll(begin, &cut, 10, &ok); + if (!ok || hour < 0 || hour > maxHour || cut > begin + 2) return INT_MIN; + begin = cut; if (begin < end && *begin == ':') { // minutes ++begin; - min = qstrtoll(begin, &begin, 10, &ok); - if (!ok || min < 0) + min = qstrtoll(begin, &cut, 10, &ok); + if (!ok || min < 0 || min > 59 || cut > begin + 2) return INT_MIN; + begin = cut; if (begin < end && *begin == ':') { // seconds ++begin; - sec = qstrtoll(begin, &begin, 10, &ok); - if (!ok || sec < 0) + sec = qstrtoll(begin, &cut, 10, &ok); + if (!ok || sec < 0 || sec > 59 || cut > begin + 2) return INT_MIN; + begin = cut; } } -- 2.16.3