From 84b3268027641401bb8ad4427a90a3cce2eb86f5 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 26 Feb 2020 19:47:34 +0100 Subject: [PATCH] netlink: Use netlink header as base to calculate bad attribute offset Userspace might send a batch that is composed of several netlink messages. The netlink_ack() function must use the pointer to the netlink header as base to calculate the bad attribute offset. Fixes: 2d4bc93368f5 ("netlink: extended ACK reporting") Signed-off-by: Pablo Neira Ayuso Signed-off-by: David S. Miller --- net/netlink/af_netlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index edf3e285e242..5313f1cec170 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2434,7 +2434,7 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, in_skb->len)) WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS, (u8 *)extack->bad_attr - - in_skb->data)); + (u8 *)nlh)); } else { if (extack->cookie_len) WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE,