From f1533cce60d1f84378c1dd925f9ef1038fa93507 Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Thu, 7 Jul 2016 09:39:29 -0300 Subject: [PATCH] sctp: fix panic when sending auth chunks 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: 90017accff61 ("sctp: Add GSO support") Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/output.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/net/sctp/output.c b/net/sctp/output.c index 1541a91d6d9d..2e9223bb1b3a 100644 --- a/net/sctp/output.c +++ b/net/sctp/output.c @@ -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; } -- 2.20.1