lineedit: plug memory leak

1 files changed, 12 insertions, 5 deletions

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index a018a53ff..a66398a95 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -81,8 +81,9 @@ static int num_ok_lines = 1;
 #endif
 
 #if ENABLE_FEATURE_GETUSERNAME_AND_HOMEDIR
-static char *user_buf = (char*)"";
-static char *home_pwd_buf = (char*)"";
+static const char null_str[] = "";
+static char *user_buf;
+static char *home_pwd_buf = (char*)null_str;
 #endif
 
 /* Put 'command_ps[cursor]', cursor++.
@@ -311,7 +312,7 @@ static void username_tab_completion(char *ud, char *with_shash_flg)
 
         if (with_shash_flg) {           /* "~/..." or "~user/..." */
                 char *sav_ud = ud - 1;
-                char *home = 0;
+                char *home = NULL;
                 char *temp;
 
                 if (*ud == '/') {       /* "~/..."     */
@@ -1119,7 +1120,7 @@ static void parse_prompt(const char *prmt_ptr)
                                 switch (c) {
 #if ENABLE_FEATURE_GETUSERNAME_AND_HOMEDIR
                                 case 'u':
-                                        pbuf = user_buf;
+                                        pbuf = user_buf ? user_buf : (char*)"";
                                         break;
 #endif
                                 case 'h':
@@ -1143,7 +1144,7 @@ static void parse_prompt(const char *prmt_ptr)
                                 case 'w':
                                         pbuf = pwd_buf;
                                         l = strlen(home_pwd_buf);
-                                        if (home_pwd_buf[0] != 0
+                                        if (l != 0
                                          && strncmp(home_pwd_buf, pbuf, l) == 0
                                          && (pbuf[l]=='/' || pbuf[l]=='\0')
                                          && strlen(pwd_buf+l)<PATH_MAX
@@ -1310,8 +1311,14 @@ int read_line_input(const char* prompt, char* command, int maxsize, line_input_t
 
                 entry = getpwuid(geteuid());
                 if (entry) {
+                        /* If we enter read_line_input for the Nth time,
+                         * they may be already allocated! Need to free. */
+                        free(user_buf);
+                        if (home_pwd_buf != null_str);
+                                free(home_pwd_buf);
                         user_buf = xstrdup(entry->pw_name);
                         home_pwd_buf = xstrdup(entry->pw_dir);
+                        /* They are not freed on exit (too small to bother) */
                 }
         }
 #endif