1 files changed, 41 insertions, 3 deletions

diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index 03ead8a9e90cc..4d0da7042affb 100644
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -25,6 +25,7 @@
 #include <linux/uaccess.h>
 #include <net/sock.h>
 #include <linux/init.h>
+#include <linux/sched/signal.h>
 
 #include <net/netlink.h>
 #include <linux/netfilter/nfnetlink.h>
@@ -37,6 +38,8 @@ MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER);
 	rcu_dereference_protected(table[(id)].subsys, \
 				  lockdep_nfnl_is_held((id)))
 
+#define NFNL_MAX_ATTR_COUNT	32
+
 static struct {
 	struct mutex				mutex;
 	const struct nfnetlink_subsystem __rcu	*subsys;
@@ -76,6 +79,13 @@ EXPORT_SYMBOL_GPL(lockdep_nfnl_is_held);
 
 int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n)
 {
+	u8 cb_id;
+
+	/* Sanity-check attr_count size to avoid stack buffer overflow. */
+	for (cb_id = 0; cb_id < n->cb_count; cb_id++)
+		if (WARN_ON(n->cb[cb_id].attr_count > NFNL_MAX_ATTR_COUNT))
+			return -EINVAL;
+
 	nfnl_lock(n->subsys_id);
 	if (table[n->subsys_id].subsys) {
 		nfnl_unlock(n->subsys_id);
@@ -185,11 +195,17 @@ replay:
 	{
 		int min_len = nlmsg_total_size(sizeof(struct nfgenmsg));
 		u8 cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type);
-		struct nlattr *cda[ss->cb[cb_id].attr_count + 1];
+		struct nlattr *cda[NFNL_MAX_ATTR_COUNT + 1];
 		struct nlattr *attr = (void *)nlh + min_len;
 		int attrlen = nlh->nlmsg_len - min_len;
 		__u8 subsys_id = NFNL_SUBSYS_ID(type);
 
+		/* Sanity-check NFNL_MAX_ATTR_COUNT */
+		if (ss->cb[cb_id].attr_count > NFNL_MAX_ATTR_COUNT) {
+			rcu_read_unlock();
+			return -ENOMEM;
+		}
+
 		err = nla_parse(cda, ss->cb[cb_id].attr_count, attr, attrlen,
 				ss->cb[cb_id].policy, extack);
 		if (err < 0) {
@@ -330,6 +346,13 @@ replay:
 	while (skb->len >= nlmsg_total_size(0)) {
 		int msglen, type;
 
+		if (fatal_signal_pending(current)) {
+			nfnl_err_reset(&err_list);
+			err = -EINTR;
+			status = NFNL_BATCH_FAILURE;
+			goto done;
+		}
+
 		memset(&extack, 0, sizeof(extack));
 		nlh = nlmsg_hdr(skb);
 		err = 0;
@@ -379,10 +402,16 @@ replay:
 		{
 			int min_len = nlmsg_total_size(sizeof(struct nfgenmsg));
 			u8 cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type);
-			struct nlattr *cda[ss->cb[cb_id].attr_count + 1];
+			struct nlattr *cda[NFNL_MAX_ATTR_COUNT + 1];
 			struct nlattr *attr = (void *)nlh + min_len;
 			int attrlen = nlh->nlmsg_len - min_len;
 
+			/* Sanity-check NFTA_MAX_ATTR */
+			if (ss->cb[cb_id].attr_count > NFNL_MAX_ATTR_COUNT) {
+				err = -ENOMEM;
+				goto ack;
+			}
+
 			err = nla_parse(cda, ss->cb[cb_id].attr_count, attr,
 					attrlen, ss->cb[cb_id].policy, NULL);
 			if (err < 0)
@@ -441,10 +470,19 @@ done:
 		kfree_skb(skb);
 		goto replay;
 	} else if (status == NFNL_BATCH_DONE) {
-		ss->commit(net, oskb);
+		err = ss->commit(net, oskb);
+		if (err == -EAGAIN) {
+			status |= NFNL_BATCH_REPLAY;
+			goto done;
+		} else if (err) {
+			ss->abort(net, oskb);
+			netlink_ack(oskb, nlmsg_hdr(oskb), err, NULL);
+		}
 	} else {
 		ss->abort(net, oskb);
 	}
+	if (ss->cleanup)
+		ss->cleanup(net);
 
 	nfnl_err_deliver(&err_list, oskb);
 	nfnl_unlock(subsys_id);