fix: correct directory ownership when creating cache dirs with sudo

When running `sudo deepin-log-viewer --reportcoredump`, directories created
under ~/.cache/deepin/deepin-log-viewer/ are owned by root, causing subsequent
normal launches to fail writing to them.

Add Utils::fixDirOwnership() to chown newly created directories to the real
logged-in user (detected via lstat(homePath)) when getuid() differs from the
real user UID. Apply it to all mkpath call sites that create cache directories
under the user's home: updateRepeatCoredumpExePaths, UserLogAccess constructor,
and UserLogAccess::createExtractSubdir.

Harden fixDirOwnership() against symlink attacks: walk the target path from
root using openat(O_DIRECTORY | O_NOFOLLOW) at each level, then fchown() the
resulting fd. This prevents a non-privileged user from pre-creating a symlink
along the path to trick the privileged sudo process into chowning arbitrary
targets outside the home directory.

Add error handling for createExtractSubdir() returning empty string (mkpath
failure) at all three call sites: skip unzip and fall back to returning
original file paths directly, preventing silent file loss.

Also add qCWarning logging for unchecked mkpath return values across the
project.

PMS: TASK-395141

Author: wangrong1069

application/dbusproxy/userlogaccess.cpp

@@ -42,7 +42,13 @@ UserLogAccess::UserLogAccess(QObject *parent)
 {
     // 初始化解压根目录：~/.cache/deepin/deepin-log-viewer/user-log
     m_extractRoot = Utils::homePath + QStringLiteral("/.cache/deepin/deepin-log-viewer/user-log");
-    QDir().mkpath(m_extractRoot);
+    if (!QDir().mkpath(m_extractRoot)) {
+        qCWarning(logUserLogAccess) << "Failed to create extract root directory:" << m_extractRoot;
+    } else {
+        // mkpath 可能同时创建父目录 deepin-log-viewer，两处均需修正属主
+        Utils::fixDirOwnership(Utils::homePath + QStringLiteral("/.cache/deepin/deepin-log-viewer"));
+        Utils::fixDirOwnership(m_extractRoot);
+    }
 
     // 清理上次残留的解压子目录
     QDir rootDir(m_extractRoot);
@@ -74,7 +80,11 @@ QString UserLogAccess::createExtractSubdir()
     // 每次调用创建独立子目录，避免并发互删
     const QString subdir = m_extractRoot + QDir::separator()
                            + QStringLiteral("extract-") + QUuid::createUuid().toString(QUuid::WithoutBraces);
-    QDir().mkpath(subdir);
+    if (!QDir().mkpath(subdir)) {
+        qCWarning(logUserLogAccess) << "Failed to create extract subdirectory:" << subdir;
+        return QString();
+    }
+    Utils::fixDirOwnership(subdir);
     return subdir;
 }
 
@@ -277,10 +287,10 @@ QStringList UserLogAccess::getFileInfo(const QString &file, bool unzip)
 
         // 独立解压子目录
         QString extractDir = createExtractSubdir();
-        QString tempFileTemplate = extractDir + QDir::separator() + "Log_extract_XXXXXX.txt";
+        QString tempFileTemplate = extractDir.isEmpty() ? QString() : extractDir + QDir::separator() + "Log_extract_XXXXXX.txt";
 
         for (int i = 0; i < fileList.count(); i++) {
-            if (fileList[i].suffix().compare("gz", Qt::CaseInsensitive) == 0 && unzip) {
+            if (!tempFileTemplate.isEmpty() && fileList[i].suffix().compare("gz", Qt::CaseInsensitive) == 0 && unzip) {
                 QString unzipFile = unzipToTempFile(fileList[i].absoluteFilePath(), tempFileTemplate);
                 if (!unzipFile.isEmpty())
                     fileNamePath.append(unzipFile);
@@ -308,10 +318,10 @@ QStringList UserLogAccess::getFileInfo(const QString &file, bool unzip)
         QFileInfoList fileList = dir.entryInfoList();
 
         QString extractDir = createExtractSubdir();
-        QString tempFileTemplate = extractDir + QDir::separator() + "Log_extract_XXXXXX.txt";
+        QString tempFileTemplate = extractDir.isEmpty() ? QString() : extractDir + QDir::separator() + "Log_extract_XXXXXX.txt";
 
         for (int i = 0; i < fileList.count(); i++) {
-            if (fileList[i].suffix().compare("gz", Qt::CaseInsensitive) == 0 && unzip) {
+            if (!tempFileTemplate.isEmpty() && fileList[i].suffix().compare("gz", Qt::CaseInsensitive) == 0 && unzip) {
                 QString unzipFile = unzipToTempFile(fileList[i].absoluteFilePath(), tempFileTemplate);
                 if (!unzipFile.isEmpty())
                     fileNamePath.append(unzipFile);
@@ -350,10 +360,10 @@ QStringList UserLogAccess::getOtherFileInfo(const QString &file, bool unzip)
     QFileInfoList fileList = dir.entryInfoList();
 
     QString extractDir = createExtractSubdir();
-    QString tempFileTemplate = extractDir + QDir::separator() + "Log_extract_XXXXXX.txt";
+    QString tempFileTemplate = extractDir.isEmpty() ? QString() : extractDir + QDir::separator() + "Log_extract_XXXXXX.txt";
 
     for (int i = 0; i < fileList.count(); i++) {
-        if (fileList[i].suffix().compare("gz", Qt::CaseInsensitive) == 0 && unzip) {
+        if (!tempFileTemplate.isEmpty() && fileList[i].suffix().compare("gz", Qt::CaseInsensitive) == 0 && unzip) {
             QString unzipFile = unzipToTempFile(fileList[i].absoluteFilePath(), tempFileTemplate);
             if (!unzipFile.isEmpty())
                 fileNamePath.append(unzipFile);

application/logbackend.cpp

@@ -2079,7 +2079,8 @@ bool LogBackend::getOutDirPath(const QString &path)
     QDir dir(tmpPath);
     if (!dir.exists()) {
         qCDebug(logApp) << "LogBackend::getOutDirPath dir does not exist, creating directory";
-         dir.mkpath(dir.absolutePath());
+         if (!dir.mkpath(dir.absolutePath()))
+             qCWarning(logApp) << "Failed to create output directory:" << dir.absolutePath();
          m_newDir = dir.exists();
          if (m_newDir)
              tmpPath = dir.absolutePath();

application/logsettings.cpp

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: 2019 - 2022 UnionTech Software Technology Co., Ltd.
+// SPDX-FileCopyrightText: 2019-2026 UnionTech Software Technology Co., Ltd.
 //
 // SPDX-License-Identifier: GPL-3.0-or-later
 
@@ -40,7 +40,8 @@ LogSettings::LogSettings(QObject *parent)
     QDir infoPath(Utils::getConfigPath());
     if (!infoPath.exists()) {
         qCDebug(logApp) << "Info path does not exist, creating it";
-        infoPath.mkpath(Utils::getConfigPath());
+        if (!infoPath.mkpath(Utils::getConfigPath()))
+            qCWarning(logApp) << "Failed to create config directory:" << Utils::getConfigPath();
     }
 
     m_configPath = infoPath.filePath("wininfo-config.conf");

application/utils.cpp

@@ -11,6 +11,10 @@
 
 #include <math.h>
 #include <pwd.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <fcntl.h>
 
 #include <QUrl>
 #include <QDir>
@@ -105,7 +109,8 @@ QString Utils::getAppDataPath()
 
     QString path = dir.filePath(qApp->applicationName());
     if (!dir.exists(path))
-        dir.mkpath(path);
+        if (!dir.mkpath(path))
+            qCWarning(logApp) << "Failed to create app data directory:" << path;
     qCDebug(logApp) << "App data path:" << path;
     return path;
 }
@@ -353,6 +358,59 @@ QString Utils::mkMutiDir(const QString &path)
     return parentDir + "/" + dirname;
 }
 
+void Utils::fixDirOwnership(const QString &dirPath)
+{
+    // 仅处理 homePath 目录下的路径，避免误改其他目录属主
+    if (!dirPath.startsWith(Utils::homePath + QLatin1Char('/'))) {
+        qCWarning(logApp) << "fixDirOwnership: dirPath is not under homePath, skip:" << dirPath;
+        return;
+    }
+
+    // 使用 lstat 获取 homePath 属主，不跟随符号链接
+    struct stat st;
+    if (lstat(Utils::homePath.toUtf8().constData(), &st) != 0) {
+        qCWarning(logApp) << "fixDirOwnership: failed to lstat homePath:" << Utils::homePath << "error:" << strerror(errno);
+        return;
+    }
+    uid_t realUID = st.st_uid;
+    gid_t realGID = st.st_gid;
+    if (getuid() == realUID) {
+        return;
+    }
+
+    // 从根目录逐级 openat(O_DIRECTORY | O_NOFOLLOW) 打开目标路径，
+    // 任一组件是符号链接则 openat 失败，拒绝继续，防止 symlink 攻击。
+    int fd = open("/", O_DIRECTORY);
+    if (fd < 0) {
+        qCWarning(logApp) << "fixDirOwnership: failed to open root directory:" << strerror(errno);
+        return;
+    }
+
+    QByteArray pathBytes = dirPath.toUtf8();
+    char *path = pathBytes.data();
+    char *saveptr = nullptr;
+    char *component = strtok_r(path, "/", &saveptr);
+    while (component != nullptr) {
+        int nextFd = openat(fd, component, O_DIRECTORY | O_NOFOLLOW);
+        if (nextFd < 0) {
+            qCWarning(logApp) << "fixDirOwnership: refused to traverse component" << component
+                              << "(possible symlink), error:" << strerror(errno);
+            close(fd);
+            return;
+        }
+        close(fd);
+        fd = nextFd;
+        component = strtok_r(nullptr, "/", &saveptr);
+    }
+
+    if (fchown(fd, realUID, realGID) != 0) {
+        qCWarning(logApp) << "fixDirOwnership: failed to fchown" << dirPath
+                          << "to uid:" << realUID << "gid:" << realGID
+                          << "error:" << strerror(errno);
+    }
+    close(fd);
+}
+
 bool Utils::checkAuthorization(const QString &actionId, qint64 applicationPid)
 {
     qCDebug(logApp) << "Checking authorization for action:" << actionId << "pid:" << applicationPid;
@@ -583,7 +641,11 @@ void Utils::updateRepeatCoredumpExePaths(const QList<LOG_REPEAT_COREDUMP_INFO> &
     // 目录不存在，则创建目录
     if (!QFileInfo::exists(fi.absolutePath())) {
         QDir dir;
-        dir.mkpath(fi.absolutePath());
+        if (!dir.mkpath(fi.absolutePath())) {
+            qCWarning(logApp) << "Failed to create directory:" << fi.absolutePath();
+        } else {
+            Utils::fixDirOwnership(fi.absolutePath());
+        }
     }
 
     // 确定当前时间范围的崩溃数据高频重复路径

application/utils.h

@@ -83,6 +83,8 @@ class Utils : public QObject
     // 查找所有物理网络接口
     static QStringList getPhysicalInterfaces();
     static QStringList expandPathWithWildcardIterator(const QString &pathWithWildcard);
+    // 修正目录属主：当进程 UID 与真实登录用户 UID 不一致时，chown 为真实用户
+    static void fixDirOwnership(const QString &dirPath);
     // 执行cmd命令
     static QByteArray executeCmd(const QString& cmd, const QStringList& args = QStringList(), const QString& workPath = QString());
     static QByteArray processCmdWithArgs(const QString &cmdStr, const QString &workPath, const QStringList &args);

logViewerService/main.cpp

@@ -50,7 +50,8 @@ int main(int argc, char *argv[])
                           .arg(qApp->applicationName());
 
     if (!dirCheck.exists(LogPath)) {
-        dirCheck.mkpath(LogPath);
+        if (!dirCheck.mkpath(LogPath))
+            qCWarning(logService) << "Failed to create log directory:" << LogPath;
     }
     QString serviceLogPath=LogPath+QString("%1.log").arg(qApp->applicationName());
     Dtk::Core::DLogManager::setlogFilePath(serviceLogPath);

logViewerService/opslogexport.cpp

@@ -190,7 +190,10 @@ bool OpsLogExport::path_exists(const string &path)
 
 bool OpsLogExport::create_directories(const string &path)
 {
-    return QDir(QString::fromStdString(path)).mkpath(".");
+    bool ok = QDir(QString::fromStdString(path)).mkpath(".");
+    if (!ok)
+        qWarning() << "Failed to create directories:" << QString::fromStdString(path);
+    return ok;
 }
 
 void OpsLogExport::copy_file_or_dir(const string &src, const string &dst_dir)
@@ -207,7 +210,8 @@ void OpsLogExport::copy_file_or_dir(const string &src, const string &dst_dir)
     if (srcInfo.isSymLink()) return;
     if (srcInfo.isFile()) {
         // 单个文件：确保目标目录存在后用 QFile::copy
-        QDir().mkpath(qDst);
+        if (!QDir().mkpath(qDst))
+            qWarning() << "Failed to create directory:" << qDst;
         QString dstFile = qDst + "/" + srcInfo.fileName();
         QFile::remove(dstFile);  // QFile::copy 要求目标不存在
         QFile::copy(qSrc, dstFile);