hwclock: alloate date_resp parsing buffer in interpret_date_string()

This makes overflowing the variable in question impossible.

Reviewed-by: J William Piggott <elseifthen@gmx.com>
Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/sys-utils/hwclock.c b/sys-utils/hwclock.c
index c5be96f542ed8209d54410926cd0e01a0d01eea5..e78929260c314d571931e981216f542a14ff4d4a 100644 (file)
--- a/sys-utils/hwclock.c
+++ b/sys-utils/hwclock.c
@@ -680,9 +680,10 @@ static int interpret_date_string(const struct hwclock_control *ctl,
                                 time_t *const time_p)
 {
        FILE *date_child_fp;
-       char date_resp[100];
+       char *date_command;
+       char *date_resp = NULL;
+       size_t len = 0;
        const char magic[] = "seconds-into-epoch=";
-       char date_command[100];
        int retcode;            /* our eventual return code */
        int rc;                 /* local return code */
 
@@ -705,7 +706,7 @@ static int interpret_date_string(const struct hwclock_control *ctl,
                return 12;
        }
 
-       sprintf(date_command, "date --date=\"%s\" +%s%%s",
+       xasprintf(&date_command, "date --date=\"%s\" +%s%%s",
                ctl->date_opt, magic);
        if (ctl->debug)
                printf(_("Issuing date command: %s\n"), date_command);
@@ -714,11 +715,15 @@ static int interpret_date_string(const struct hwclock_control *ctl,
        if (date_child_fp == NULL) {
                warn(_("Unable to run 'date' program in /bin/sh shell. "
                            "popen() failed"));
+               free(date_command);
                return 10;
        }
 
-       if (!fgets(date_resp, sizeof(date_resp), date_child_fp))
-               date_resp[0] = '\0';    /* in case fgets fails */
+       if (getline(&date_resp, &len, date_child_fp) < 0) {
+               warn(_("getline() failed"));
+               free(date_command);
+               return 15;
+       }
        if (ctl->debug)
                printf(_("response from date command = %s\n"), date_resp);
        if (strncmp(date_resp, magic, sizeof(magic) - 1) != 0) {
@@ -750,6 +755,8 @@ static int interpret_date_string(const struct hwclock_control *ctl,
                                       ctl->date_opt, *time_p);
                }
        }
+       free(date_command);
+       free(date_resp);
        pclose(date_child_fp);
 
        return retcode;