diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 03db95a..35c4e85 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2508,8 +2508,8 @@ int skb_splice_bits(struct sk_buff *skb, unsigned int offset, unsigned int flags); void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); unsigned int skb_zerocopy_headlen(const struct sk_buff *from); -void skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, - int len, int hlen); +int skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, + int len, int hlen); void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len); int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen); void skb_scrub_packet(struct sk_buff *skb, bool xnet); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 3f14c63..73f0291 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2127,25 +2127,31 @@ EXPORT_SYMBOL_GPL(skb_zerocopy_headlen); * * The `hlen` as calculated by skb_zerocopy_headlen() specifies the * headroom in the `to` buffer. + * + * Return value: + * 0: everything is OK + * -ENOMEM: couldn't orphan frags of from due to lack of memory + * -EFAULT: skb_copy_bits() found some problem with geometry */ -void +int skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen) { int i, j = 0; int plen = 0; /* length of skb->head fragment */ + int ret; struct page *page; unsigned int offset; BUG_ON(!from->head_frag && !hlen); /* dont bother with small payloads */ - if (len <= skb_tailroom(to)) { - skb_copy_bits(from, 0, skb_put(to, len), len); - return; - } + if (len <= skb_tailroom(to)) + return skb_copy_bits(from, 0, skb_put(to, len), len); if (hlen) { - skb_copy_bits(from, 0, skb_put(to, hlen), hlen); + ret = skb_copy_bits(from, 0, skb_put(to, hlen), hlen); + if (unlikely(ret)) + return ret; len -= hlen; } else { plen = min_t(int, skb_headlen(from), len); @@ -2163,6 +2169,11 @@ skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen) to->len += len + plen; to->data_len += len + plen; + if (unlikely(skb_orphan_frags(from, GFP_ATOMIC))) { + skb_tx_error(from); + return -ENOMEM; + } + for (i = 0; i < skb_shinfo(from)->nr_frags; i++) { if (!len) break; @@ -2173,6 +2184,8 @@ skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen) j++; } skb_shinfo(to)->nr_frags = j; + + return 0; } EXPORT_SYMBOL_GPL(skb_zerocopy); diff --git a/net/netfilter/nfnetlink_queue_core.c b/net/netfilter/nfnetlink_queue_core.c index f072fe8..108120f 100644 --- a/net/netfilter/nfnetlink_queue_core.c +++ b/net/netfilter/nfnetlink_queue_core.c @@ -354,13 +354,16 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, skb = nfnetlink_alloc_skb(net, size, queue->peer_portid, GFP_ATOMIC); - if (!skb) + if (!skb) { + skb_tx_error(entskb); return NULL; + } nlh = nlmsg_put(skb, 0, 0, NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET, sizeof(struct nfgenmsg), 0); if (!nlh) { + skb_tx_error(entskb); kfree_skb(skb); return NULL; } @@ -488,13 +491,15 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, nla->nla_type = NFQA_PAYLOAD; nla->nla_len = nla_attr_size(data_len); - skb_zerocopy(skb, entskb, data_len, hlen); + if (skb_zerocopy(skb, entskb, data_len, hlen)) + goto nla_put_failure; } nlh->nlmsg_len = skb->len; return skb; nla_put_failure: + skb_tx_error(entskb); kfree_skb(skb); net_err_ratelimited("nf_queue: error creating packet message\n"); return NULL; diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c index c53fe0c..63b5471 100644 --- a/net/openvswitch/datapath.c +++ b/net/openvswitch/datapath.c @@ -464,7 +464,9 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb, } nla->nla_len = nla_attr_size(skb->len); - skb_zerocopy(user_skb, skb, skb->len, hlen); + err = skb_zerocopy(user_skb, skb, skb->len, hlen); + if (err) + goto out; /* Pad OVS_PACKET_ATTR_PACKET if linear copy was performed */ if (!(dp->user_features & OVS_DP_F_UNALIGNED)) { @@ -478,6 +480,7 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb, err = genlmsg_unicast(ovs_dp_get_net(dp), user_skb, upcall_info->portid); out: + skb_tx_error(skb); kfree_skb(nskb); return err; }