Commit 84b32680 authored Feb 26, 2020 by Pablo Neira Ayuso Committed by David S. Miller Feb 29, 2020

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: 2d4bc933 ("netlink: extended ACK reporting")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent d64c7a08

net/netlink/af_netlink.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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,

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