From aa0f697e45286a6b5f0ceca9418acf54b9099d99 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 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 --- 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 96a069d725e9..36328ab88bdd 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -4669,6 +4669,9 @@ enum sctp_disposition 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(struct sctp_chunkhdr))) return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, -- cgit v1.2.3