From 629d2823abf957bcbcba32154f1f6fd49bdb850c Mon Sep 17 00:00:00 2001 From: Xin Long Date: Wed, 20 Oct 2021 07:42:41 -0400 Subject: sctp: use init_tag from inithdr for ABORT chunk [ Upstream commit 4f7019c7eb33967eb87766e0e4602b5576873680 ] Currently Linux SCTP uses the verification tag of the existing SCTP asoc when failing to process and sending the packet with the ABORT chunk. This will result in the peer accepting the ABORT chunk and removing the SCTP asoc. One could exploit this to terminate a SCTP asoc. This patch is to fix it by always using the initiate tag of the received INIT chunk for the ABORT chunk to be sent. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/sctp/sm_statefuns.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/sctp/sm_statefuns.c') diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index a9ba6f2bb8c8..b83f90bb1a6e 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -6027,6 +6027,7 @@ static struct sctp_packet *sctp_ootb_pkt_new(struct net *net, * yet. */ switch (chunk->chunk_hdr->type) { + case SCTP_CID_INIT: case SCTP_CID_INIT_ACK: { sctp_initack_chunk_t *initack; -- cgit v1.2.3 From c0b5302e3a74997b57985b561e776269d1951ac7 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Wed, 20 Oct 2021 07:42:45 -0400 Subject: sctp: add vtag check in sctp_sf_violation [ Upstream commit aa0f697e45286a6b5f0ceca9418acf54b9099d99 ] sctp_sf_violation() is called when processing HEARTBEAT_ACK chunk in cookie_wait state, and some other places are also using it. The vtag in the chunk's sctphdr should be verified, otherwise, as later in chunk length check, it may send abort with the existent asoc's vtag, which can be exploited by one to cook a malicious chunk to terminate a SCTP asoc. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/sctp/sm_statefuns.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'net/sctp/sm_statefuns.c') diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index b83f90bb1a6e..53bb631ec490 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -4337,6 +4337,9 @@ sctp_disposition_t sctp_sf_violation(struct net *net, { struct sctp_chunk *chunk = arg; + if (!sctp_vtag_verify(chunk, asoc)) + return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); + /* Make sure that the chunk has a valid length. */ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, -- cgit v1.2.3