SCTP : Fix to process bundled ASCONF chunk correctly

If ASCONF chunk is bundled with other chunks as the first chunk, when
process the ASCONF parameters, full packet data will be process as the
parameters of the ASCONF chunk, not only the real parameters. So if you
send a ASCONF chunk bundled with other chunks, you will get an unexpect
result.
This problem also exists when ASCONF-ACK chunk is bundled with other chunks.

This patch fix this problem.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index c377e4e8f653..5de4729fe993 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -2848,10 +2848,11 @@ struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
 
         __be16  err_code;
         int     length = 0;
-        int     chunk_len = asconf->skb->len;
+        int     chunk_len;
         __u32   serial;
         int     all_param_pass = 1;
 
+        chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
         hdr = (sctp_addiphdr_t *)asconf->skb->data;
         serial = ntohl(hdr->serial);
 
@@ -2990,7 +2991,7 @@ static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
         sctp_addip_param_t      *asconf_ack_param;
         sctp_errhdr_t           *err_param;
         int                     length;
-        int                     asconf_ack_len = asconf_ack->skb->len;
+        int                     asconf_ack_len;
         __be16                  err_code;
 
         if (no_err)
@@ -2998,6 +2999,9 @@ static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
         else
                 err_code = SCTP_ERROR_REQ_REFUSED;
 
+        asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
+                             sizeof(sctp_chunkhdr_t);
+
         /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
          * the first asconf_ack parameter.
          */