From b2f543949acd1ba64313fdad9e672ef47550d773 Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Wed, 5 Sep 2018 16:55:11 +0200 Subject: net/af_iucv: fix skb handling on HiperTransport xmit error When sending an skb, afiucv_hs_send() bails out on various error conditions. But currently the caller has no way of telling whether the skb was freed or not - resulting in potentially either a) leaked skbs from iucv_send_ctrl(), or b) double-free's from iucv_sock_sendmsg(). As dev_queue_xmit() will always consume the skb (even on error), be consistent and also free the skb from all other error paths. This way callers no longer need to care about managing the skb. Signed-off-by: Julian Wiedmann Reviewed-by: Ursula Braun Signed-off-by: David S. Miller --- net/iucv/af_iucv.c | 34 +++++++++++++++++++++++----------- 1 file changed, 23 insertions(+), 11 deletions(-) (limited to 'net/iucv') diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c index 01000c14417f..e2f16a0173a9 100644 --- a/net/iucv/af_iucv.c +++ b/net/iucv/af_iucv.c @@ -351,20 +351,28 @@ static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock, memcpy(&phs_hdr->iucv_hdr, imsg, sizeof(struct iucv_message)); skb->dev = iucv->hs_dev; - if (!skb->dev) - return -ENODEV; - if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(skb->dev)) - return -ENETDOWN; + if (!skb->dev) { + err = -ENODEV; + goto err_free; + } + if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(skb->dev)) { + err = -ENETDOWN; + goto err_free; + } if (skb->len > skb->dev->mtu) { - if (sock->sk_type == SOCK_SEQPACKET) - return -EMSGSIZE; - else - skb_trim(skb, skb->dev->mtu); + if (sock->sk_type == SOCK_SEQPACKET) { + err = -EMSGSIZE; + goto err_free; + } + skb_trim(skb, skb->dev->mtu); } skb->protocol = cpu_to_be16(ETH_P_AF_IUCV); nskb = skb_clone(skb, GFP_ATOMIC); - if (!nskb) - return -ENOMEM; + if (!nskb) { + err = -ENOMEM; + goto err_free; + } + skb_queue_tail(&iucv->send_skb_q, nskb); err = dev_queue_xmit(skb); if (net_xmit_eval(err)) { @@ -375,6 +383,10 @@ static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock, WARN_ON(atomic_read(&iucv->msg_recv) < 0); } return net_xmit_eval(err); + +err_free: + kfree_skb(skb); + return err; } static struct sock *__iucv_get_sock_by_name(char *nm) @@ -1167,7 +1179,7 @@ static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg, err = afiucv_hs_send(&txmsg, sk, skb, 0); if (err) { atomic_dec(&iucv->msg_sent); - goto fail; + goto out; } } else { /* Classic VM IUCV transport */ skb_queue_tail(&iucv->send_skb_q, skb); -- cgit v1.2.3-59-g8ed1b