Commit 7ef36fea authored by Houcheng Lin's avatar Houcheng Lin Committed by Luis Henriques

netfilter: nf_log: release skbuff on nlmsg put failure

commit b51d3fa3 upstream.

The kernel should reserve enough room in the skb so that the DONE
message can always be appended.  However, in case of e.g. new attribute
erronously not being size-accounted for, __nfulnl_send() will still
try to put next nlmsg into this full skbuf, causing the skb to be stuck
forever and blocking delivery of further messages.

Fix issue by releasing skb immediately after nlmsg_put error and
WARN() so we can track down the cause of such size mismatch.

[ fw@strlen.de: add tailroom/len info to WARN ]
Signed-off-by: default avatarHoucheng Lin <houcheng@gmail.com>
Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
parent 87f00629
......@@ -346,26 +346,25 @@ nfulnl_alloc_skb(struct net *net, u32 peer_portid, unsigned int inst_size,
return skb;
}
static int
static void
__nfulnl_send(struct nfulnl_instance *inst)
{
int status = -1;
if (inst->qlen > 1) {
struct nlmsghdr *nlh = nlmsg_put(inst->skb, 0, 0,
NLMSG_DONE,
sizeof(struct nfgenmsg),
0);
if (!nlh)
if (WARN_ONCE(!nlh, "bad nlskb size: %u, tailroom %d\n",
inst->skb->len, skb_tailroom(inst->skb))) {
kfree_skb(inst->skb);
goto out;
}
}
status = nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid,
MSG_DONTWAIT);
nfnetlink_unicast(inst->skb, inst->net, inst->peer_portid,
MSG_DONTWAIT);
out:
inst->qlen = 0;
inst->skb = NULL;
out:
return status;
}
static void
......
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