zcip: fix slow environment leak

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

3 files changed, 12 insertions, 6 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 0317c7d6a..6abf88218 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1485,6 +1485,9 @@ extern void selinux_or_die(void) FAST_FUNC;
  *   HOME=pw->pw_dir
  *   SHELL=shell
  * else does nothing
+ *
+ * NB: CHANGEENV and CLEARENV use setenv() - this leaks memory!
+ * If setup_environment() is used is vforked child, this leaks memory _in parent too_!
  */
 #define SETUP_ENV_CHANGEENV (1 << 0)
 #define SETUP_ENV_CLEARENV  (1 << 1)
diff --git a/networking/ifplugd.c b/networking/ifplugd.c
index c36bc9524..9bc1a075f 100644
--- a/networking/ifplugd.c
+++ b/networking/ifplugd.c
@@ -342,10 +342,8 @@ static int run_script(const char *action)
         /* r < 0 - can't exec, 0 <= r < 0x180 - exited, >=0x180 - killed by sig (r-0x180) */
         r = spawn_and_wait(argv);
 
-        unsetenv(IFPLUGD_ENV_PREVIOUS);
-        unsetenv(IFPLUGD_ENV_CURRENT);
-        free(env_PREVIOUS);
-        free(env_CURRENT);
+        bb_unsetenv_and_free(env_PREVIOUS);
+        bb_unsetenv_and_free(env_CURRENT);
 
         bb_error_msg("exit code: %d", r & 0xff);
         return (option_mask32 & FLAG_IGNORE_RETVAL) ? 0 : r;
diff --git a/networking/zcip.c b/networking/zcip.c
index 232165efa..94174a165 100644
--- a/networking/zcip.c
+++ b/networking/zcip.c
@@ -183,6 +183,7 @@ static int run(char *argv[3], const char *param, uint32_t nip)
         int status;
         const char *addr = addr; /* for gcc */
         const char *fmt = "%s %s %s" + 3;
+        char *env_ip = env_ip;
 
         argv[2] = (char*)param;
 
@@ -190,12 +191,16 @@ static int run(char *argv[3], const char *param, uint32_t nip)
 
         if (nip != 0) {
                 addr = nip_to_a(nip);
-                xsetenv("ip", addr);
+                /* Must not use setenv() repeatedly, it leaks memory. Use putenv() */
+                env_ip = xasprintf("ip=%s", addr);
+                putenv(env_ip);
                 fmt -= 3;
         }
         bb_error_msg(fmt, argv[2], argv[0], addr);
-
         status = spawn_and_wait(argv + 1);
+        if (nip != 0)
+                bb_unsetenv_and_free(env_ip);
+
         if (status < 0) {
                 bb_perror_msg("%s %s %s" + 3, argv[2], argv[0]);
                 return -errno;