From 05599f5769188731199ddb370ec270bccf0f7c6a Mon Sep 17 00:00:00 2001 From: Ahmad Samir <a.samirh78@gmail.com> Date: Wed, 8 Mar 2023 13:49:21 +0200 Subject: [PATCH 085/147] QFSFileEngine: fix overflow bug when using lseek64 QT_LSEEK (lseek64()) returns QT_OFF_T, which is off64_t on 32bit systems. The return from the lseek64() call was being assigned to an int, which meant that if the returned value is > INT_MAX it will overflow and the value becomes -1, and since errno would be EOVERFLOW the code would fail to open the file. Fix the issue by assigning the return value to QT_OFF_T. Thanks to Giuseppe for pointing out the issue in the code review. Found by compiling with -Wshorten-64-to-32. [ChangeLog][QtCore][QFile] Fixed a bug where opening a file in append mode may fail if the file size was bigger than INT_MAX. Pick-to: 6.5 6.4 6.2 5.15 Change-Id: Iad33e3192f37466643a1218d38e5ecc2baaa7dc9 Reviewed-by: Thiago Macieira <thiago.macieira@intel.com> (cherry picked from commit 5bffb47d6e45260953bc679e1e9582322064b753) --- src/corelib/io/qfsfileengine.cpp | 2 +- src/corelib/io/qfsfileengine_unix.cpp | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/src/corelib/io/qfsfileengine.cpp b/src/corelib/io/qfsfileengine.cpp index 3042eac2f0..a862ce9166 100644 --- a/src/corelib/io/qfsfileengine.cpp +++ b/src/corelib/io/qfsfileengine.cpp @@ -361,7 +361,7 @@ bool QFSFileEnginePrivate::openFd(QIODevice::OpenMode openMode, int fd) // Seek to the end when in Append mode. if (openMode & QFile::Append) { - int ret; + QT_OFF_T ret; do { ret = QT_LSEEK(fd, 0, SEEK_END); } while (ret == -1 && errno == EINTR); diff --git a/src/corelib/io/qfsfileengine_unix.cpp b/src/corelib/io/qfsfileengine_unix.cpp index 4610e9306c..65e921c15a 100644 --- a/src/corelib/io/qfsfileengine_unix.cpp +++ b/src/corelib/io/qfsfileengine_unix.cpp @@ -141,7 +141,7 @@ bool QFSFileEnginePrivate::nativeOpen(QIODevice::OpenMode openMode) // Seek to the end when in Append mode. if (flags & QFile::Append) { - int ret; + QT_OFF_T ret; do { ret = QT_LSEEK(fd, 0, SEEK_END); } while (ret == -1 && errno == EINTR); -- 2.40.1