lash: make -c work; crush buffer overrun and free of non-malloced ptr

(from Mats Erik Andersson <mats.andersson64@comhem.se>)

diff --git a/shell/lash.c b/shell/lash.c
index 99b6173bf67b80a29565465f5b84bdefb1145479..58d770fd84b6facfc7a3b8985875bbf8d241649f 100644 (file)
--- a/shell/lash.c
+++ b/shell/lash.c
@@ -114,7 +114,7 @@ static int builtin_read(struct child_prog *cmd);
 /* function prototypes for shell stuff */
 static void checkjobs(struct jobset *job_list);
 static void remove_job(struct jobset *j_list, struct job *job);
-static int get_command(FILE * source, char *command);
+static int get_command_bufsiz(FILE * source, char *command);
 static int parse_command(char **command_ptr, struct job *job, int *inbg);
 static int run_command(struct job *newjob, int inbg, int outpipe[2]);
 static int pseudo_exec(struct child_prog *cmd) ATTRIBUTE_NORETURN;
@@ -649,15 +649,14 @@ static inline const char* setup_prompt_string(void)
 static line_input_t *line_input_state;
 #endif
 
-static int get_command(FILE * source, char *command)
+static int get_command_bufsiz(FILE * source, char *command)
 {
        const char *prompt_str;
 
        if (source == NULL) {
                if (local_pending_command) {
                        /* a command specified (-c option): return it & mark it done */
-                       strcpy(command, local_pending_command);
-                       free(local_pending_command);
+                       strncpy(command, local_pending_command, BUFSIZ);
                        local_pending_command = NULL;
                        return 0;
                }
@@ -1363,12 +1362,12 @@ static int busy_loop(FILE * input)
                        checkjobs(&job_list);
 
                        if (!next_command) {
-                               if (get_command(input, command))
+                               if (get_command_bufsiz(input, command))
                                        break;
                                next_command = command;
                        }
 
-                       if (! expand_arguments(next_command)) {
+                       if (!expand_arguments(next_command)) {
                                free(command);
                                command = xzalloc(BUFSIZ);
                                next_command = NULL;
@@ -1455,8 +1454,6 @@ static void free_memory(void)
        if (cwd && cwd != bb_msg_unknown) {
                free((char*)cwd);
        }
-       if (local_pending_command)
-               free(local_pending_command);
 
        if (job_list.fg && !job_list.fg->running_progs) {
                remove_job(&job_list, job_list.fg);
@@ -1538,7 +1535,7 @@ int lash_main(int argc_l, char **argv_l)
 
        opt = getopt32(argc_l, argv_l, "+ic:", &local_pending_command);
 #define LASH_OPT_i (1<<0)
-#define LASH_OPT_c (1<<2)
+#define LASH_OPT_c (1<<1)
        if (opt & LASH_OPT_c) {
                input = NULL;
                optind++;