sctp: fix panic when sending auth chunks (f1533cce) · Commits · 戴 / test

When we introduced GSO support, if using auth the auth chunk was being left queued on the packet even after the final segment was generated. Later on sctp_transmit_packet it calls sctp_packet_reset, which zeroed the packet len while not accounting for this left-over. This caused more space to be used the next packet due to the chunk still being queued, but space which wasn't allocated as its size wasn't accounted. The fix is to only queue it back when we know that we are going to generate another segment. Fixes: ("sctp: Add GSO support") Signed-off-by:

Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/sctp/output.c

+15 −3

Original line number	Diff line number	Diff line
		@@ -582,9 +582,7 @@ int sctp_packet_transmit(struct sctp_packet *packet, gfp_t gfp)
		*/
		pkt_size -= WORD_ROUND(chunk->skb->len);

		if (chunk == packet->auth && !list_empty(&packet->chunk_list))
		list_add(&chunk->list, &packet->chunk_list);
		else if (!sctp_chunk_is_data(chunk))
		if (!sctp_chunk_is_data(chunk) && chunk != packet->auth)
		sctp_chunk_free(chunk);

		if (!pkt_size)
		@@ -605,6 +603,18 @@ int sctp_packet_transmit(struct sctp_packet *packet, gfp_t gfp)
		(struct sctp_auth_chunk *)auth,
		gfp);

		if (packet->auth) {
		if (!list_empty(&packet->chunk_list)) {
		/* We will generate more packets, so re-queue
		* auth chunk.
		*/
		list_add(&chunk->list, &packet->chunk_list);
		} else {
		sctp_chunk_free(packet->auth);
		packet->auth = NULL;
		}
		}

		if (!gso)
		break;

		@@ -735,6 +745,8 @@ err:
		}
		goto out;
		nomem:
		if (packet->auth && list_empty(&packet->auth->list))
		sctp_chunk_free(packet->auth);
		err = -ENOMEM;
		goto err;
		}

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