netlink: test for all flags of the NLM_F_DUMP composite

Due to NLM_F_DUMP is composed of two bits, NLM_F_ROOT | NLM_F_MATCH,
when doing "if (x & NLM_F_DUMP)", it tests for _either_ of the bits
being set. Because NLM_F_MATCH's value overlaps with NLM_F_EXCL,
non-dump requests with NLM_F_EXCL set are mistaken as dump requests.

Substitute the condition to test for _all_ bits being set.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/rtnetlink.c

@@ -1820,7 +1820,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	if (kind != 2 && security_netlink_recv(skb, CAP_NET_ADMIN))
 		return -EPERM;
 
-	if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
+	if (kind == 2 && (nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {
 		struct sock *rtnl;
 		rtnl_dumpit_func dumpit;
 

net/ipv4/inet_diag.c

@@ -858,7 +858,7 @@ static int inet_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	    nlmsg_len(nlh) < hdrlen)
 		return -EINVAL;
 
-	if (nlh->nlmsg_flags & NLM_F_DUMP) {
+	if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {
 		if (nlmsg_attrlen(nlh, hdrlen)) {
 			struct nlattr *attr;
 

net/netfilter/nf_conntrack_netlink.c

@@ -928,7 +928,7 @@ ctnetlink_get_conntrack(struct sock *ctnl, struct sk_buff *skb,
 	u16 zone;
 	int err;
 
-	if (nlh->nlmsg_flags & NLM_F_DUMP)
+	if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP)
 		return netlink_dump_start(ctnl, skb, nlh, ctnetlink_dump_table,
 					  ctnetlink_done);
 
@@ -1790,7 +1790,7 @@ ctnetlink_get_expect(struct sock *ctnl, struct sk_buff *skb,
 	u16 zone;
 	int err;
 
-	if (nlh->nlmsg_flags & NLM_F_DUMP) {
+	if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {
 		return netlink_dump_start(ctnl, skb, nlh,
 					  ctnetlink_exp_dump_table,
 					  ctnetlink_exp_done);

net/netlink/genetlink.c

@@ -519,7 +519,7 @@ static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	    security_netlink_recv(skb, CAP_NET_ADMIN))
 		return -EPERM;
 
-	if (nlh->nlmsg_flags & NLM_F_DUMP) {
+	if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {
 		if (ops->dumpit == NULL)
 			return -EOPNOTSUPP;
 

net/xfrm/xfrm_user.c

@@ -2187,7 +2187,7 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 
 	if ((type == (XFRM_MSG_GETSA - XFRM_MSG_BASE) ||
 	     type == (XFRM_MSG_GETPOLICY - XFRM_MSG_BASE)) &&
-	    (nlh->nlmsg_flags & NLM_F_DUMP)) {
+	    (nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {
 		if (link->dump == NULL)
 			return -EINVAL;