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-rw-r--r--net/sctp/sm_statefuns.c59
1 files changed, 44 insertions, 15 deletions
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 2b9a832b29a7..8cdba51ec076 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -636,8 +636,9 @@ sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
*/
chunk->subh.cookie_hdr =
(struct sctp_signed_cookie *)chunk->skb->data;
- skb_pull(chunk->skb,
- ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t));
+ if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
+ sizeof(sctp_chunkhdr_t)))
+ goto nomem;
/* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
* "Z" will reply with a COOKIE ACK chunk after building a TCB
@@ -965,7 +966,8 @@ sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
*/
chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
- skb_pull(chunk->skb, paylen);
+ if (!pskb_pull(chunk->skb, paylen))
+ goto nomem;
reply = sctp_make_heartbeat_ack(asoc, chunk,
chunk->subh.hb_hdr, paylen);
@@ -1860,8 +1862,9 @@ sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
* are in good shape.
*/
chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
- skb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
- sizeof(sctp_chunkhdr_t));
+ if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
+ sizeof(sctp_chunkhdr_t)))
+ goto nomem;
/* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
* of a duplicate COOKIE ECHO match the Verification Tags of the
@@ -5151,7 +5154,9 @@ static int sctp_eat_data(const struct sctp_association *asoc,
int tmp;
__u32 tsn;
int account_value;
+ struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
struct sock *sk = asoc->base.sk;
+ int rcvbuf_over = 0;
data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
@@ -5162,10 +5167,16 @@ static int sctp_eat_data(const struct sctp_association *asoc,
/* ASSERT: Now skb->data is really the user data. */
/*
- * if we are established, and we have used up our receive
- * buffer memory, drop the frame
- */
- if (asoc->state == SCTP_STATE_ESTABLISHED) {
+ * If we are established, and we have used up our receive buffer
+ * memory, think about droping the frame.
+ * Note that we have an opportunity to improve performance here.
+ * If we accept one chunk from an skbuff, we have to keep all the
+ * memory of that skbuff around until the chunk is read into user
+ * space. Therefore, once we accept 1 chunk we may as well accept all
+ * remaining chunks in the skbuff. The data_accepted flag helps us do
+ * that.
+ */
+ if ((asoc->state == SCTP_STATE_ESTABLISHED) && (!chunk->data_accepted)) {
/*
* If the receive buffer policy is 1, then each
* association can allocate up to sk_rcvbuf bytes
@@ -5176,9 +5187,25 @@ static int sctp_eat_data(const struct sctp_association *asoc,
account_value = atomic_read(&asoc->rmem_alloc);
else
account_value = atomic_read(&sk->sk_rmem_alloc);
-
- if (account_value > sk->sk_rcvbuf)
- return SCTP_IERROR_IGNORE_TSN;
+ if (account_value > sk->sk_rcvbuf) {
+ /*
+ * We need to make forward progress, even when we are
+ * under memory pressure, so we always allow the
+ * next tsn after the ctsn ack point to be accepted.
+ * This lets us avoid deadlocks in which we have to
+ * drop frames that would otherwise let us drain the
+ * receive queue.
+ */
+ if ((sctp_tsnmap_get_ctsn(map) + 1) != tsn)
+ return SCTP_IERROR_IGNORE_TSN;
+
+ /*
+ * We're going to accept the frame but we should renege
+ * to make space for it. This will send us down that
+ * path later in this function.
+ */
+ rcvbuf_over = 1;
+ }
}
/* Process ECN based congestion.
@@ -5226,6 +5253,7 @@ static int sctp_eat_data(const struct sctp_association *asoc,
datalen -= sizeof(sctp_data_chunk_t);
deliver = SCTP_CMD_CHUNK_ULP;
+ chunk->data_accepted = 1;
/* Think about partial delivery. */
if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
@@ -5242,7 +5270,8 @@ static int sctp_eat_data(const struct sctp_association *asoc,
* large spill over.
*/
if (!asoc->rwnd || asoc->rwnd_over ||
- (datalen > asoc->rwnd + asoc->frag_point)) {
+ (datalen > asoc->rwnd + asoc->frag_point) ||
+ rcvbuf_over) {
/* If this is the next TSN, consider reneging to make
* room. Note: Playing nice with a confused sender. A
@@ -5250,8 +5279,8 @@ static int sctp_eat_data(const struct sctp_association *asoc,
* space and in the future we may want to detect and
* do more drastic reneging.
*/
- if (sctp_tsnmap_has_gap(&asoc->peer.tsn_map) &&
- (sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + 1) == tsn) {
+ if (sctp_tsnmap_has_gap(map) &&
+ (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
deliver = SCTP_CMD_RENEGE;
} else {