xtables: arp: Store target entry properly and compare them relevantly
Fixes a segfault issue when deleting a rule.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/iptables/nft-arp.c b/iptables/nft-arp.c
index 10c7b63..0460066 100644
--- a/iptables/nft-arp.c
+++ b/iptables/nft-arp.c
@@ -276,17 +276,16 @@
fw->arp.invflags |= ipt_to_arpt_flags(flags);
}
-static void nft_arp_parse_target(struct xtables_target *t, void *data)
+static void nft_arp_parse_target(struct xtables_target *target, void *data)
{
struct arpt_entry *fw = data;
- size_t size = sizeof(struct arpt_entry);
- struct xt_entry_target **target;
+ struct xt_entry_target **t;
- fw->target_offset = size;
- fw->next_offset = size + t->t->u.target_size;
+ fw->target_offset = offsetof(struct arpt_entry, elems);
+ fw->next_offset = fw->target_offset + target->t->u.target_size;
- target = (void *) fw + fw->target_offset;
- *target = t->t;
+ t = (void *) &fw->elems;
+ *t = target->t;
}
static void nft_arp_parse_immediate(const char *jumpto, bool nft_goto,
@@ -297,10 +296,13 @@
target = xtables_find_target(XT_STANDARD_TARGET,
XTF_LOAD_MUST_SUCCEED);
- size = sizeof(struct xt_entry_target) + target->size;
+
+ size = XT_ALIGN(sizeof(struct xt_entry_target)) + target->size;
+
target->t = xtables_calloc(1, size);
target->t->u.target_size = size;
strcpy(target->t->u.user.name, jumpto);
+ target->t->u.user.revision = target->revision;
nft_arp_parse_target(target, data);
}
@@ -598,16 +600,11 @@
struct arpt_entry *fw = data;
struct xt_entry_target *t_fw, *t_this;
char *targname_fw, *targname_this;
- struct xtables_target *target_fw, *target_this;
struct arpt_entry this = {};
/* Delete by matching rule case */
nft_rule_to_arpt_entry(r, &this);
- DEBUGP("comparing with... ");
-
-/* nft_rule_print_save(&this, r, NFT_RULE_APPEND, 0); */
-
if (!ops->is_same(fw, &this))
return false;
@@ -617,19 +614,20 @@
targname_fw = t_fw->u.user.name;
targname_this = t_this->u.user.name;
- target_fw = xtables_find_target(targname_fw, XTF_TRY_LOAD);
- target_this = xtables_find_target(targname_this, XTF_TRY_LOAD);
-
- if (target_fw != NULL && target_this != NULL) {
- if (!compare_targets(target_fw, target_this)) {
+ if (!strcmp(targname_fw, targname_this) &&
+ (!strcmp(targname_fw, "mangle") ||
+ !strcmp(targname_fw, "CLASSIFY"))) {
+ if (memcmp(t_fw->data, t_this->data,
+ t_fw->u.user.target_size - sizeof(*t_fw)) != 0) {
DEBUGP("Different target\n");
return false;
}
- } else {
- if (strcmp(targname_fw, targname_this) != 0) {
- DEBUGP("Different verdict\n");
- return false;
- }
+ return true;
+ }
+
+ if (strcmp(targname_fw, targname_this) != 0) {
+ DEBUGP("Different verdict\n");
+ return false;
}
return true;
diff --git a/iptables/nft-shared.h b/iptables/nft-shared.h
index 3d1f433..7260fdd 100644
--- a/iptables/nft-shared.h
+++ b/iptables/nft-shared.h
@@ -178,11 +178,11 @@
#include <linux/netfilter_arp/arp_tables.h>
-static inline struct xt_entry_target *nft_arp_get_target(struct arpt_entry *fw)
+static inline struct xt_entry_target *nft_arp_get_target(struct arpt_entry *fw)
{
struct xt_entry_target **target;
- target = (void *) fw + fw->target_offset;
+ target = (void *) &fw->elems;
return *target;
}
diff --git a/iptables/xtables-arp.c b/iptables/xtables-arp.c
index 407fb06..8072d90 100644
--- a/iptables/xtables-arp.c
+++ b/iptables/xtables-arp.c
@@ -819,12 +819,12 @@
size = sizeof(struct arpt_entry);
- e = xtables_malloc(size + target->u.target_size);
+ e = xtables_malloc(size);
*e = *fw;
- e->target_offset = size;
- e->next_offset = size + target->u.target_size;
+ e->target_offset = offsetof(struct arpt_entry, elems);
+ e->next_offset = e->target_offset + target->u.target_size;
- t = (void *) e + e->target_offset;
+ t = (void *) &e->elems;
*t = target;
return e;
