From 9fcb95a105758b81ef0131cd18e2db5149f13e95 Mon Sep 17 00:00:00 2001 From: Wei Yongjun Date: Thu, 25 Dec 2008 16:58:11 -0800 Subject: sctp: Avoid memory overflow while FWD-TSN chunk is received with bad stream ID If FWD-TSN chunk is received with bad stream ID, the sctp will not do the validity check, this may cause memory overflow when overwrite the TSN of the stream ID. The FORWARD-TSN chunk is like this: FORWARD-TSN chunk Type = 192 Flags = 0 Length = 172 NewTSN = 99 Stream = 10000 StreamSequence = 0xFFFF This patch fix this problem by discard the chunk if stream ID is not less than MIS. Signed-off-by: Wei Yongjun Signed-off-by: Vlad Yasevich Signed-off-by: David S. Miller --- net/sctp/sm_statefuns.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'net') diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index 9f2a3eb656e..1c4e5d6c29c 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -3689,6 +3689,7 @@ sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep, { struct sctp_chunk *chunk = arg; struct sctp_fwdtsn_hdr *fwdtsn_hdr; + struct sctp_fwdtsn_skip *skip; __u16 len; __u32 tsn; @@ -3718,6 +3719,12 @@ sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep, if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0) goto discard_noforce; + /* Silently discard the chunk if stream-id is not valid */ + sctp_walk_fwdtsn(skip, chunk) { + if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams) + goto discard_noforce; + } + sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn)); if (len > sizeof(struct sctp_fwdtsn_hdr)) sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN, @@ -3749,6 +3756,7 @@ sctp_disposition_t sctp_sf_eat_fwd_tsn_fast( { struct sctp_chunk *chunk = arg; struct sctp_fwdtsn_hdr *fwdtsn_hdr; + struct sctp_fwdtsn_skip *skip; __u16 len; __u32 tsn; @@ -3778,6 +3786,12 @@ sctp_disposition_t sctp_sf_eat_fwd_tsn_fast( if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0) goto gen_shutdown; + /* Silently discard the chunk if stream-id is not valid */ + sctp_walk_fwdtsn(skip, chunk) { + if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams) + goto gen_shutdown; + } + sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn)); if (len > sizeof(struct sctp_fwdtsn_hdr)) sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN, -- cgit v1.2.3-70-g09d2