iptables: Plug memleaks in print_firewall()

When adding a rule in verbose mode, valgrind prints:

192 bytes in 1 blocks are definitely lost in loss record 1 of 2
   at 0x48417E5: malloc (vg_replace_malloc.c:381)
   by 0x486B158: xtables_malloc (xtables.c:446)
   by 0x486C1F6: xtables_find_match (xtables.c:826)
   by 0x10E684: print_match (iptables.c:115)
   by 0x10E684: print_firewall (iptables.c:169)
   by 0x10FC0C: print_firewall_line (iptables.c:196)
   by 0x10FC0C: append_entry (iptables.c:221)
   by 0x10FC0C: do_command4 (iptables.c:776)
   by 0x10E45B: iptables_main (iptables-standalone.c:59)
   by 0x49A2349: (below main) (in /lib64/libc.so.6)

200 bytes in 1 blocks are definitely lost in loss record 2 of 2
   at 0x48417E5: malloc (vg_replace_malloc.c:381)
   by 0x486B158: xtables_malloc (xtables.c:446)
   by 0x486BBD6: xtables_find_target (xtables.c:956)
   by 0x10E579: print_firewall (iptables.c:145)
   by 0x10FC0C: print_firewall_line (iptables.c:196)
   by 0x10FC0C: append_entry (iptables.c:221)
   by 0x10FC0C: do_command4 (iptables.c:776)
   by 0x10E45B: iptables_main (iptables-standalone.c:59)
   by 0x49A2349: (below main) (in /lib64/libc.so.6)

If the match/target was cloned, it needs to be freed. Basically a bug since
day 1.

Signed-off-by: Phil Sutter <phil@nwl.cc>

diff --git a/iptables/ip6tables.c b/iptables/ip6tables.c
index 062b2b152d554d25f73d594eeda8e95ce4f6ba91..1d2326570a71d321faf6c0a5afb2769c4ec17ba7 100644 (file)
--- a/iptables/ip6tables.c
+++ b/iptables/ip6tables.c
@@ -122,6 +122,9 @@ print_match(const struct xt_entry_match *m,
                        printf("%s%s ", match->name, unsupported_rev);
                else
                        printf("%s ", match->name);
+
+               if (match->next == match)
+                       free(match);
        } else {
                if (name[0])
                        printf("UNKNOWN match `%s' ", name);
@@ -179,6 +182,9 @@ print_firewall(const struct ip6t_entry *fw,
                        tg->print(&fw->ipv6, t, format & FMT_NUMERIC);
                else if (target->print)
                        printf(" %s%s", target->name, unsupported_rev);
+
+               if (target->next == target)
+                       free(target);
        } else if (t->u.target_size != sizeof(*t))
                printf("[%u bytes of unknown target data] ",
                       (unsigned int)(t->u.target_size - sizeof(*t)));

diff --git a/iptables/iptables.c b/iptables/iptables.c
index 0351b39fb7e3e1b0178d0b10ec648b7974c66bc5..d246198f49d270d1b782aae5eb1396519caad165 100644 (file)
--- a/iptables/iptables.c
+++ b/iptables/iptables.c
@@ -122,6 +122,9 @@ print_match(const struct xt_entry_match *m,
                        printf("%s%s ", match->name, unsupported_rev);
                else
                        printf("%s ", match->name);
+
+               if (match->next == match)
+                       free(match);
        } else {
                if (name[0])
                        printf("UNKNOWN match `%s' ", name);
@@ -178,6 +181,9 @@ print_firewall(const struct ipt_entry *fw,
                        tg->print(&fw->ip, t, format & FMT_NUMERIC);
                else if (target->print)
                        printf(" %s%s", target->name, unsupported_rev);
+
+               if (target->next == target)
+                       free(target);
        } else if (t->u.target_size != sizeof(*t))
                printf("[%u bytes of unknown target data] ",
                       (unsigned int)(t->u.target_size - sizeof(*t)));