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>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 750db57f3bb3..a5f7535aab5b 100644
--- a/net/core/rtnetlink.c
+++ b/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;