path: root/net/sctp
diff options
authorXin Long <lucien.xin@gmail.com>2018-11-18 15:07:38 +0800
committerDavid S. Miller <davem@davemloft.net>2018-11-19 12:39:05 -0800
commit02968ccf0125d39b08ecef5946300a8a873c0942 (patch)
treece9c31025aa5c8c06708ac3c527a1a8ea4ff4d0a /net/sctp
parenta36b5444b1ec79ed5fedd12295626c05b4f788eb (diff)
sctp: count sk_wmem_alloc by skb truesize in sctp_packet_transmit
Now sctp increases sk_wmem_alloc by 1 when doing set_owner_w for the skb allocked in sctp_packet_transmit and decreases by 1 when freeing this skb. But when this skb goes through networking stack, some subcomponents might change skb->truesize and add the same amount on sk_wmem_alloc. However sctp doesn't know the amount to decrease by, it would cause a leak on sk->sk_wmem_alloc and the sock can never be freed. Xiumei found this issue when it hit esp_output_head() by using sctp over ipsec, where skb->truesize is added and so is sk->sk_wmem_alloc. Since sctp has used sk_wmem_queued to count for writable space since Commit cd305c74b0f8 ("sctp: use sk_wmem_queued to check for writable space"), it's ok to fix it by counting sk_wmem_alloc by skb truesize in sctp_packet_transmit. Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible") Reported-by: Xiumei Mu <xmu@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sctp')
1 files changed, 1 insertions, 20 deletions
diff --git a/net/sctp/output.c b/net/sctp/output.c
index 67939ad99c01..88dfa6ae1fb4 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -396,25 +396,6 @@ finish:
return retval;
-static void sctp_packet_release_owner(struct sk_buff *skb)
- sk_free(skb->sk);
-static void sctp_packet_set_owner_w(struct sk_buff *skb, struct sock *sk)
- skb_orphan(skb);
- skb->sk = sk;
- skb->destructor = sctp_packet_release_owner;
- /*
- * The data chunks have already been accounted for in sctp_sendmsg(),
- * therefore only reserve a single byte to keep socket around until
- * the packet has been transmitted.
- */
- refcount_inc(&sk->sk_wmem_alloc);
static void sctp_packet_gso_append(struct sk_buff *head, struct sk_buff *skb)
if (SCTP_OUTPUT_CB(head)->last == head)
@@ -601,7 +582,7 @@ int sctp_packet_transmit(struct sctp_packet *packet, gfp_t gfp)
if (!head)
goto out;
skb_reserve(head, packet->overhead + MAX_HEADER);
- sctp_packet_set_owner_w(head, sk);
+ skb_set_owner_w(head, sk);
/* set sctp header */
sh = skb_push(head, sizeof(struct sctphdr));