netfilter: nf_log: release skbuff on nlmsg put failure

commit b51d3fa364885a2c1e1668f88776c67c95291820 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: Houcheng Lin <houcheng@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Houcheng Lin 2014-10-23 10:36:08 +02:00 committed by Greg Kroah-Hartman
parent 07b170693a
commit 0bf7a5e16a
1 changed files with 8 additions and 9 deletions

View File

@ -348,26 +348,25 @@ nfulnl_alloc_skb(u32 peer_portid, unsigned int inst_size, unsigned int pkt_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