1 files changed, 24 insertions, 0 deletions

diff --git a/tools/thermal/tmon/tmon.c b/tools/thermal/tmon/tmon.c
index b30f531173e4..059e0becb386 100644
--- a/tools/thermal/tmon/tmon.c
+++ b/tools/thermal/tmon/tmon.c
@@ -142,6 +142,7 @@ static void start_syslog(void)
 static void prepare_logging(void)
 {
         int i;
+        struct stat logstat;
 
         if (!logging)
                 return;
@@ -152,6 +153,29 @@ static void prepare_logging(void)
                 return;
         }
 
+        if (lstat(TMON_LOG_FILE, &logstat) < 0) {
+                syslog(LOG_ERR, "Unable to stat log file %s\n", TMON_LOG_FILE);
+                fclose(tmon_log);
+                tmon_log = NULL;
+                return;
+        }
+
+        /* The log file must be a regular file owned by us */
+        if (S_ISLNK(logstat.st_mode)) {
+                syslog(LOG_ERR, "Log file is a symlink.  Will not log\n");
+                fclose(tmon_log);
+                tmon_log = NULL;
+                return;
+        }
+
+        if (logstat.st_uid != getuid()) {
+                syslog(LOG_ERR, "We don't own the log file.  Not logging\n");
+                fclose(tmon_log);
+                tmon_log = NULL;
+                return;
+        }
+
+
         fprintf(tmon_log, "#----------- THERMAL SYSTEM CONFIG -------------\n");
         for (i = 0; i < ptdata.nr_tz_sensor; i++) {
                 char binding_str[33]; /* size of long + 1 */