secure: change insecure system function

system() -> fork() + execve()

Change-Id: I0a8a062013dddfbce03f11ddb6e02962775eb3e9
Signed-off-by: Sooyoung Ha <yoosah.ha@samsung.com>

diff --git a/src/sdb.c b/src/sdb.c
index 7b81403..f614bfb 100644 (file)
--- a/src/sdb.c
+++ b/src/sdb.c
@@ -1671,6 +1671,29 @@ static int init_sdk_userinfo() {
     return 0;
 }
 
+static int safe_system(char *cmd, char *argv[], char *envp[]) {
+    pid_t pid;
+    int status;
+
+    pid = fork();
+    switch (pid) {
+        case -1:
+            return -1;
+        case 0:
+            execve(cmd, argv, envp);
+            D("- exec '%s' failed: (errno:%d) -\n", cmd, errno);
+            exit(-1);
+        default:
+            for (;;) {
+                pid_t p = waitpid(pid, &status, 0);
+                if (p == pid) {
+                    break;
+                }
+            }
+    }
+    return 0;
+}
+
 static void init_sdk_requirements() {
     struct stat st;
 
@@ -1684,11 +1707,35 @@ static void init_sdk_requirements() {
 
     if (g_sdk_home_dir != NULL && stat(g_sdk_home_dir, &st) == 0) {
         if (st.st_uid != g_sdk_user_id || st.st_gid != g_sdk_group_id) {
-            char cmd[128];
-            snprintf(cmd, sizeof(cmd), "/usr/bin/chown %s:%s %s -R", SDK_USER_NAME, SDK_USER_NAME, g_sdk_home_dir);
-            if (system(cmd) < 0) {
+            char* cmd = "/usr/bin/chown";
+            char params[128];
+            char* envp[128];
+            int envp_cnt = 0;
+            int i = 0;
+
+            envp[envp_cnt++] = g_strdup("TERM=linux");
+            envp[envp_cnt++] = g_strdup("DISPLAY=:0");
+            envp[envp_cnt] = NULL;
+
+            snprintf(params, sizeof(params), "%s %s:%s %s -R", cmd, SDK_USER_NAME, SDK_USER_NAME, g_sdk_home_dir);
+
+            char* args[] = {
+                cmd,
+                params,
+                NULL,
+            };
+            if (safe_system(cmd, args, envp) < 0) {
                 D("failed to change ownership to sdk user to %s\n", g_sdk_home_dir);
             }
+
+            /* free environment variables */
+            if (envp_cnt > 0) {
+                for (i = 0; i < envp_cnt; i++) {
+                    if (envp[i]) {
+                        g_free(envp[i]);
+                    }
+                }
+            }
         }
     }