1 files changed, 15 insertions, 14 deletions

diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 24e556e..2f5ef5b 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -168,11 +168,12 @@ get_entry(const void *base, unsigned int offset)
 
 /* All zeroes == unconditional rule. */
 /* Mildly perf critical (only if packet tracing is on) */
-static inline bool unconditional(const struct ipt_ip *ip)
+static inline bool unconditional(const struct ipt_entry *e)
 {
 	static const struct ipt_ip uncond;
 
-	return memcmp(ip, &uncond, sizeof(uncond)) == 0;
+	return e->target_offset == sizeof(struct ipt_entry) &&
+	       memcmp(&e->ip, &uncond, sizeof(uncond)) == 0;
 #undef FWINV
 }
 
@@ -230,11 +231,10 @@ get_chainname_rulenum(const struct ipt_entry *s, const struct ipt_entry *e,
 	} else if (s == e) {
 		(*rulenum)++;
 
-		if (s->target_offset == sizeof(struct ipt_entry) &&
+		if (unconditional(s) &&
 		    strcmp(t->target.u.kernel.target->name,
 			   XT_STANDARD_TARGET) == 0 &&
-		   t->verdict < 0 &&
-		   unconditional(&s->ip)) {
+		   t->verdict < 0) {
 			/* Tail of chains: STANDARD target (return/policy) */
 			*comment = *chainname == hookname
 				? comments[NF_IP_TRACE_COMMENT_POLICY]
@@ -468,11 +468,10 @@ mark_source_chains(const struct xt_table_info *newinfo,
 			e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
 
 			/* Unconditional return/END. */
-			if ((e->target_offset == sizeof(struct ipt_entry) &&
+			if ((unconditional(e) &&
 			     (strcmp(t->target.u.user.name,
 				     XT_STANDARD_TARGET) == 0) &&
-			     t->verdict < 0 && unconditional(&e->ip)) ||
-			    visited) {
+			     t->verdict < 0) || visited) {
 				unsigned int oldpos, size;
 
 				if ((strcmp(t->target.u.user.name,
@@ -705,7 +704,7 @@ static bool check_underflow(const struct ipt_entry *e)
 	const struct xt_entry_target *t;
 	unsigned int verdict;
 
-	if (!unconditional(&e->ip))
+	if (!unconditional(e))
 		return false;
 	t = ipt_get_target_c(e);
 	if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
@@ -727,7 +726,8 @@ check_entry_size_and_hooks(struct ipt_entry *e,
 	unsigned int h;
 
 	if ((unsigned long)e % __alignof__(struct ipt_entry) != 0 ||
-	    (unsigned char *)e + sizeof(struct ipt_entry) >= limit) {
+	    (unsigned char *)e + sizeof(struct ipt_entry) >= limit ||
+	    (unsigned char *)e + e->next_offset > limit) {
 		duprintf("Bad offset %p\n", e);
 		return -EINVAL;
 	}
@@ -747,9 +747,9 @@ check_entry_size_and_hooks(struct ipt_entry *e,
 			newinfo->hook_entry[h] = hook_entries[h];
 		if ((unsigned char *)e - base == underflows[h]) {
 			if (!check_underflow(e)) {
-				pr_err("Underflows must be unconditional and "
-				       "use the STANDARD target with "
-				       "ACCEPT/DROP\n");
+				pr_debug("Underflows must be unconditional and "
+					 "use the STANDARD target with "
+					 "ACCEPT/DROP\n");
 				return -EINVAL;
 			}
 			newinfo->underflow[h] = underflows[h];
@@ -1484,7 +1484,8 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
 
 	duprintf("check_compat_entry_size_and_hooks %p\n", e);
 	if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0 ||
-	    (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit) {
+	    (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit ||
+	    (unsigned char *)e + e->next_offset > limit) {
 		duprintf("Bad offset %p, limit = %p\n", e, limit);
 		return -EINVAL;
 	}