From 10b3bf54406bb7f4e78da9bb2a485c5c986678ad Mon Sep 17 00:00:00 2001 From: Xin Long Date: Fri, 14 Jul 2017 22:07:33 +0800 Subject: [PATCH] sctp: fix an array overflow when all ext chunks are set Marcelo noticed an array overflow caused by commit c28445c3cb07 ("sctp: add reconf_enable in asoc ep and netns"), in which sctp would add SCTP_CID_RECONF into extensions when reconf_enable is set in sctp_make_init and sctp_make_init_ack. Then now when all ext chunks are set, 4 ext chunk ids can be put into extensions array while extensions array size is 3. It would cause a kernel panic because of this overflow. This patch is to fix it by defining extensions array size is 4 in both sctp_make_init and sctp_make_init_ack. Fixes: c28445c3cb07 ("sctp: add reconf_enable in asoc ep and netns") Signed-off-by: Xin Long Signed-off-by: David S. Miller --- net/sctp/sm_make_chunk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 4e16b02ed832..6110447fe51d 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -228,7 +228,7 @@ struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, sctp_adaptation_ind_param_t aiparam; sctp_supported_ext_param_t ext_param; int num_ext = 0; - __u8 extensions[3]; + __u8 extensions[4]; struct sctp_paramhdr *auth_chunks = NULL, *auth_hmacs = NULL; @@ -396,7 +396,7 @@ struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, sctp_adaptation_ind_param_t aiparam; sctp_supported_ext_param_t ext_param; int num_ext = 0; - __u8 extensions[3]; + __u8 extensions[4]; struct sctp_paramhdr *auth_chunks = NULL, *auth_hmacs = NULL, *auth_random = NULL; -- 2.20.1