Fixes the crash reported in Bugzilla #1131 where a malformed parameter that
specifies the table option during a restore can create an invalid pointer.
It was discovered during fuzz testing that options like '-ftf'
can cause a segfault. A parameter that includes a 't' is not currently
filtered correctly.

Improves the filtering to:
Filter a beginning '-' followed by a character other than '-' and then a 't'
anywhere in the parameter. This filters parameters like '-ftf'.
Filter a beginning '--t'. Because the getopt_long function allows abbreviations,
any parameter beginning with '--t' will be treated as '--table'. As no other
iptables option begins with a 't' this won't filter out other options.

Signed-off-by: Oliver Ford <ojf...@gmail.com>
---
 iptables/ip6tables-restore.c |  9 +++++----
 iptables/iptables-restore.c  |  9 +++++----
 iptables/iptables-xml.c      | 11 +++++------
 iptables/xtables-restore.c   |  9 +++++----
 4 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/iptables/ip6tables-restore.c b/iptables/ip6tables-restore.c
index 39a881d..46e9fae 100644
--- a/iptables/ip6tables-restore.c
+++ b/iptables/ip6tables-restore.c
@@ -165,11 +165,12 @@ static void add_param_to_argv(char *parsestart)
                        param_buffer[param_len] = '\0';
 
                        /* check if table name specified */
-                       if (!strncmp(param_buffer, "-t", 2)
-                            || !strncmp(param_buffer, "--table", 8)) {
+                       if ((param_buffer[0] == '-' && param_buffer[1] != '-'
+                               && strchr(param_buffer, 't'))
+                               || !strncmp(param_buffer, "--t", 3)) {
                                xtables_error(PARAMETER_PROBLEM,
-                               "The -t option (seen in line %u) cannot be "
-                               "used in ip6tables-restore.\n", line);
+                                       "The -t option (seen in line %u) cannot 
be "
+                                       "used in ip6tables-restore.\n", line);
                                exit(1);
                        }
 
diff --git a/iptables/iptables-restore.c b/iptables/iptables-restore.c
index 876fe06..9b06395 100644
--- a/iptables/iptables-restore.c
+++ b/iptables/iptables-restore.c
@@ -162,11 +162,12 @@ static void add_param_to_argv(char *parsestart)
                        param_buffer[param_len] = '\0';
 
                        /* check if table name specified */
-                       if (!strncmp(param_buffer, "-t", 2)
-                           || !strncmp(param_buffer, "--table", 8)) {
+                       if ((param_buffer[0] == '-' && param_buffer[1] != '-'
+                               && strchr(param_buffer, 't'))
+                               || !strncmp(param_buffer, "--t", 3)) {
                                xtables_error(PARAMETER_PROBLEM,
-                               "The -t option (seen in line %u) cannot be "
-                               "used in iptables-restore.\n", line);
+                                       "The -t option (seen in line %u) cannot 
be "
+                                       "used in iptables-restore.\n", line);
                                exit(1);
                        }
 
diff --git a/iptables/iptables-xml.c b/iptables/iptables-xml.c
index 2e093b5..d836ff4 100644
--- a/iptables/iptables-xml.c
+++ b/iptables/iptables-xml.c
@@ -819,13 +819,12 @@ iptables_xml_main(int argc, char *argv[])
                                        *(param_buffer + param_len) = '\0';
 
                                        /* check if table name specified */
-                                       if (!strncmp(param_buffer, "-t", 3)
-                                           || !strncmp(param_buffer,
-                                                       "--table", 8)) {
+                                       if ((param_buffer[0] == '-' && 
param_buffer[1] != '-'
+                                               && strchr(param_buffer, 't'))
+                                               || !strncmp(param_buffer, 
"--t", 3)) {
                                                xtables_error(PARAMETER_PROBLEM,
-                                                          "Line %u seems to 
have a "
-                                                          "-t table option.\n",
-                                                          line);
+                                                       "Line %u seems to have 
a "
+                                                       "-t table option.\n", 
line);
                                                exit(1);
                                        }
 
diff --git a/iptables/xtables-restore.c b/iptables/xtables-restore.c
index 15824f0..994e04e 100644
--- a/iptables/xtables-restore.c
+++ b/iptables/xtables-restore.c
@@ -136,11 +136,12 @@ static void add_param_to_argv(char *parsestart)
                        param_buffer[param_len] = '\0';
 
                        /* check if table name specified */
-                       if (!strncmp(param_buffer, "-t", 2)
-                           || !strncmp(param_buffer, "--table", 8)) {
+                       if ((param_buffer[0] == '-' && param_buffer[1] != '-'
+                               && strchr(param_buffer, 't'))
+                               || !strncmp(param_buffer, "--t", 3)) {
                                xtables_error(PARAMETER_PROBLEM,
-                               "The -t option (seen in line %u) cannot be "
-                               "used in xtables-restore.\n", line);
+                                       "The -t option (seen in line %u) cannot 
be "
+                                       "used in xtables-restore.\n", line);
                                exit(1);
                        }
 
-- 
2.11.0

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