[PATCH 4.4 10/20] netlink: avoid a double skb free in genlmsg_mcast()

Greg Kroah-Hartman
2018-03-29T18:00:46Z

From: Nicolas Dichtel <nicolas.dichtel@6wind.com>

[ Upstream commit 02a2385f37a7c6594c9d89b64c4a1451276f08eb ]

nlmsg_multicast() consumes always the skb, thus the original skb must be
freed only when this function is called with a clone.

Fixes: cb9f7a9a5c96 ("netlink: ensure to loop over all netns in genlmsg_multicast_allns()")
Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/netlink/genetlink.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -1143,7 +1143,7 @@ static int genlmsg_mcast(struct sk_buff
if (!err)
delivered = true;
else if (err != -ESRCH)
- goto error;
+ return err;
return delivered ? 0 : -ESRCH;
error:
kfree_skb(skb);