From 3fe720d1e27b16ac19c4fba412dae3acc375d029 Mon Sep 17 00:00:00 2001
From: Bruno Herrera <bruherrera@gmail.com>
Date: Mon, 25 Sep 2017 07:34:34 -0600
Subject: [PATCH] Fixes for problems found by Coverity in the apps/ repository:

    nshlib/nsh_parse.c: Avoid truncating the strcmp result into a unsigned char variable.

    nshlib/nsh_netcmds.c: Check for valid hostip before using it.

    nshlib/nsh_ddcmd.c: Fix resouce leak when 'if=' or 'of=' params are repeated in the command line.  For example:

       dd if=/dev/null if=/dev/zero of=/dev/null or
       dd if=/dev/zero of=/dev/zero of=/dev/null
---
 nshlib/nsh_ddcmd.c   | 12 +++++++++++-
 nshlib/nsh_netcmds.c | 27 +++++++++++++++------------
 nshlib/nsh_parse.c   |  6 +++---
 3 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/nshlib/nsh_ddcmd.c b/nshlib/nsh_ddcmd.c
index 88d934d1a..7f2e82bac 100644
--- a/nshlib/nsh_ddcmd.c
+++ b/nshlib/nsh_ddcmd.c
@@ -246,10 +246,20 @@ int cmd_dd(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
     {
       if (strncmp(argv[i], "if=", 3) == 0)
         {
+          if (infile != NULL)
+            {
+              free(infile);
+            }
+
           infile = nsh_getfullpath(vtbl, &argv[i][3]);
         }
       else if (strncmp(argv[i], "of=", 3) == 0)
         {
+          if (outfile != NULL)
+            {
+              free(outfile);
+            }
+
           outfile = nsh_getfullpath(vtbl, &argv[i][3]);
         }
       else if (strncmp(argv[i], "bs=", 3) == 0)
@@ -267,7 +277,7 @@ int cmd_dd(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
     }
 
 #ifndef CAN_PIPE_FROM_STD
-  if (!infile || !outfile)
+  if (infile == NULL || outfile == NULL)
     {
       nsh_output(vtbl, g_fmtargrequired, g_dd);
       goto errout_with_paths;
diff --git a/nshlib/nsh_netcmds.c b/nshlib/nsh_netcmds.c
index 3d20116de..d48cc69cf 100644
--- a/nshlib/nsh_netcmds.c
+++ b/nshlib/nsh_netcmds.c
@@ -997,21 +997,24 @@ int cmd_ifconfig(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
   else
 #endif
     {
+      if (hostip != NULL)
+        {
 #if defined(CONFIG_NSH_DHCPC)
-      if (!strcmp(hostip, "dhcp"))
-        {
-          /* Set DHCP addr */
+          if (!strcmp(hostip, "dhcp"))
+            {
+              /* Set DHCP addr */
 
-          ninfo("DHCPC Mode\n");
-          gip = addr.s_addr = 0;
-        }
-      else
+              ninfo("DHCPC Mode\n");
+              gip = addr.s_addr = 0;
+            }
+          else
 #endif
-        {
-          /* Set host IP address */
+            {
+              /* Set host IP address */
 
-          ninfo("Host IP: %s\n", hostip);
-          gip = addr.s_addr = inet_addr(hostip);
+              ninfo("Host IP: %s\n", hostip);
+              gip = addr.s_addr = inet_addr(hostip);
+            }
         }
 
       netlib_set_ipv4addr(ifname, &addr);
@@ -1020,7 +1023,7 @@ int cmd_ifconfig(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
 
 #ifdef CONFIG_NET_IPv6
 #ifdef CONFIG_NET_IPv4
-  if (inet6)
+  if (inet6i != NULL)
 #endif
     {
 #warning Missing Logic
diff --git a/nshlib/nsh_parse.c b/nshlib/nsh_parse.c
index 1dca1825b..5fe259779 100644
--- a/nshlib/nsh_parse.c
+++ b/nshlib/nsh_parse.c
@@ -1497,10 +1497,10 @@ static int nsh_loop(FAR struct nsh_vtbl_s *vtbl, FAR char **ppcmd,
     {
       /* Check if the command is preceded by "while" or "until" */
 
-      whilematch = strcmp(cmd, "while");
-      untilmatch = strcmp(cmd, "until");
+      whilematch = strcmp(cmd, "while") == 0;
+      untilmatch = strcmp(cmd, "until") == 0;
 
-      if (whilematch == 0 || untilmatch == 0)
+      if (whilematch || untilmatch)
         {
           uint8_t state;