[PATCH 7/8] netfilter: nf_log: release skbuff on nlmsg put failure
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2014-10-27 21:36:42
Also in:
netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Houcheng Lin <redacted> 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 <redacted> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- net/netfilter/nfnetlink_log.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index 2d02eac3..5f1be5b 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c@@ -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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1.7.10.4