From: Marcelo Ricardo Leitner
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
Signed-off-by: David S. Miller
Signed-off-by: Yang Yingliang
Reviewed-by: Xiu Jianfeng
Reviewed-by: Yue Haibing
Signed-off-by: Yang Yingliang
Signed-off-by: Yu Changchun
---
net/sctp/input.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/sctp/input.c b/net/sctp/input.c
index 07bd59a98205..0b09f296df2d 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -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);
--
2.22.0
