sctp: validate chunk size in __rcv_asconf_lookup

mainline inclusion
from mainline-v5.14-rc1
commit b6ffe7671b24689c09faa5675dd58f93758a97ae
category: bugfix
issue: #I4589I
CVE: CVE-2021-3655

---------------------------

In one of the fallbacks that SCTP has for identifying an association for an
incoming packet, it looks for AddIp chunk (from ASCONF) and take a peek.
Thing is, at this stage nothing was validating that the chunk actually had
enough content for that, allowing the peek to happen over uninitialized
memory.

Similar check already exists in actual asconf handling in
sctp_verify_asconf().

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Yu Changchun <yuchangchun1@huawei.com>
This commit is contained in:
Marcelo Ricardo Leitner 2021-08-13 00:12:42 +08:00 committed by Zachery Wu
parent 2fed19bebe
commit 8da6a014f4

View File

@ -1125,6 +1125,9 @@ static struct sctp_association *__sctp_rcv_asconf_lookup(
union sctp_addr_param *param;
union sctp_addr paddr;
if (ntohs(ch->length) < sizeof(*asconf) + sizeof(struct sctp_paramhdr))
return NULL;
/* Skip over the ADDIP header and find the Address parameter */
param = (union sctp_addr_param *)(asconf + 1);