1 files changed, 18 insertions, 8 deletions

diff --git a/applets/applets.c b/applets/applets.c
index fb37fbea5..13b406ae5 100644
--- a/applets/applets.c
+++ b/applets/applets.c
@@ -48,14 +48,15 @@ static const char usage_messages[] = ""
 /* The -1 arises because of the {0,NULL,0,-1} entry. */
 const unsigned short NUM_APPLETS = sizeof(applets) / sizeof(applets[0]) - 1;
 
-
 const struct bb_applet *current_applet;
 const char *applet_name ATTRIBUTE_EXTERNALLY_VISIBLE;
 #if !BB_MMU
 bool re_execed;
 #endif
 
-
+#if ENABLE_FEATURE_SUID
+static uid_t ruid;  /* real uid */
+#endif
 
 #if ENABLE_FEATURE_SUID_CONFIG
 
@@ -143,6 +144,10 @@ static void parse_config_file(void)
 
         assert(!suid_config); /* Should be set to NULL by bss init. */
 
+        ruid = getuid();
+        if (ruid == 0) /* run by root - don't need to even read config file */
+                return;
+
         if ((stat(config_file, &st) != 0)       /* No config file? */
          || !S_ISREG(st.st_mode)                /* Not a regular file? */
          || (st.st_uid != 0)                    /* Not owned by root? */
@@ -324,15 +329,21 @@ static void parse_config_file(void)
         }
 }
 #else
-#define parse_config_file() ((void)0)
+static inline void parse_config_file(void)
+{
+        ruid = getuid();
+}
 #endif /* FEATURE_SUID_CONFIG */
 
 
 #if ENABLE_FEATURE_SUID
 static void check_suid(const struct bb_applet *applet)
 {
-        uid_t ruid = getuid();               /* real [ug]id */
-        uid_t rgid = getgid();
+        uid_t rgid;  /* real gid */
+
+        if (ruid == 0) /* set by parse_config_file() */
+                return; /* run by root - no need to check more */
+        rgid = getgid();
 
 #if ENABLE_FEATURE_SUID_CONFIG
         if (suid_cfg_readable) {
@@ -387,7 +398,7 @@ static void check_suid(const struct bb_applet *applet)
                 if (geteuid())
                         bb_error_msg_and_die("applet requires root privileges!");
         } else if (applet->need_suid == _BB_SUID_NEVER) {
-                xsetgid(rgid);                          /* drop all privileges */
+                xsetgid(rgid);  /* drop all privileges */
                 xsetuid(ruid);
         }
 }
@@ -636,8 +647,7 @@ int main(int argc, char **argv)
         if (s)
                 applet_name = s + 1;
 
-        if (ENABLE_FEATURE_SUID_CONFIG)
-                parse_config_file();
+        parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
 
         /* Set locale for everybody except 'init' */
         if (ENABLE_LOCALE_SUPPORT && getpid() != 1)