From d0b2f91bede3bd5e3d24dd6803e56eee959c1797 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Thu, 20 Oct 2016 00:10:27 -0300
Subject: Linux-libre 4.8.2-gnu

---
 net/sctp/inqueue.c | 72 ++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 54 insertions(+), 18 deletions(-)

(limited to 'net/sctp/inqueue.c')

diff --git a/net/sctp/inqueue.c b/net/sctp/inqueue.c
index b335ffcef..6437aa97c 100644
--- a/net/sctp/inqueue.c
+++ b/net/sctp/inqueue.c
@@ -128,13 +128,25 @@ struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue)
 	 * at this time.
 	 */
 
-	if ((chunk = queue->in_progress)) {
+	chunk = queue->in_progress;
+	if (chunk) {
 		/* There is a packet that we have been working on.
 		 * Any post processing work to do before we move on?
 		 */
 		if (chunk->singleton ||
 		    chunk->end_of_packet ||
 		    chunk->pdiscard) {
+			if (chunk->head_skb == chunk->skb) {
+				chunk->skb = skb_shinfo(chunk->skb)->frag_list;
+				goto new_skb;
+			}
+			if (chunk->skb->next) {
+				chunk->skb = chunk->skb->next;
+				goto new_skb;
+			}
+
+			if (chunk->head_skb)
+				chunk->skb = chunk->head_skb;
 			sctp_chunk_free(chunk);
 			chunk = queue->in_progress = NULL;
 		} else {
@@ -150,34 +162,58 @@ struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue)
 	if (!chunk) {
 		struct list_head *entry;
 
+next_chunk:
 		/* Is the queue empty?  */
-		if (list_empty(&queue->in_chunk_list))
+		entry = sctp_list_dequeue(&queue->in_chunk_list);
+		if (!entry)
 			return NULL;
 
-		entry = queue->in_chunk_list.next;
-		chunk = queue->in_progress =
-			list_entry(entry, struct sctp_chunk, list);
-		list_del_init(entry);
+		chunk = list_entry(entry, struct sctp_chunk, list);
 
-		/* This is the first chunk in the packet.  */
-		chunk->singleton = 1;
-		ch = (sctp_chunkhdr_t *) chunk->skb->data;
-		chunk->data_accepted = 0;
+		if ((skb_shinfo(chunk->skb)->gso_type & SKB_GSO_SCTP) == SKB_GSO_SCTP) {
+			/* GSO-marked skbs but without frags, handle
+			 * them normally
+			 */
+			if (skb_shinfo(chunk->skb)->frag_list)
+				chunk->head_skb = chunk->skb;
+
+			/* skbs with "cover letter" */
+			if (chunk->head_skb && chunk->skb->data_len == chunk->skb->len)
+				chunk->skb = skb_shinfo(chunk->skb)->frag_list;
+
+			if (WARN_ON(!chunk->skb)) {
+				__SCTP_INC_STATS(dev_net(chunk->skb->dev), SCTP_MIB_IN_PKT_DISCARDS);
+				sctp_chunk_free(chunk);
+				goto next_chunk;
+			}
+		}
 
 		if (chunk->asoc)
 			sock_rps_save_rxhash(chunk->asoc->base.sk, chunk->skb);
+
+		queue->in_progress = chunk;
+
+new_skb:
+		/* This is the first chunk in the packet.  */
+		ch = (sctp_chunkhdr_t *) chunk->skb->data;
+		chunk->singleton = 1;
+		chunk->data_accepted = 0;
+		chunk->pdiscard = 0;
+		chunk->auth = 0;
+		chunk->has_asconf = 0;
+		chunk->end_of_packet = 0;
+		if (chunk->head_skb) {
+			struct sctp_input_cb
+				*cb = SCTP_INPUT_CB(chunk->skb),
+				*head_cb = SCTP_INPUT_CB(chunk->head_skb);
+
+			cb->chunk = head_cb->chunk;
+			cb->af = head_cb->af;
+		}
 	}
 
 	chunk->chunk_hdr = ch;
 	chunk->chunk_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
-	/* In the unlikely case of an IP reassembly, the skb could be
-	 * non-linear. If so, update chunk_end so that it doesn't go past
-	 * the skb->tail.
-	 */
-	if (unlikely(skb_is_nonlinear(chunk->skb))) {
-		if (chunk->chunk_end > skb_tail_pointer(chunk->skb))
-			chunk->chunk_end = skb_tail_pointer(chunk->skb);
-	}
 	skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t));
 	chunk->subh.v = NULL; /* Subheader is no longer valid.  */
 
-- 
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