From: Marcelo Ricardo Leitner marcelo.leitner@gmail.com
mainline inclusion from mainline-5.14-rc1 commit b6ffe7671b24689c09faa5675dd58f93758a97ae bugzilla: 177765 https://gitee.com/openeuler/kernel/issues/I4DDEL CVE: CVE-2021-3655
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
--------------------------------
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: Chen Jun chenjun102@huawei.com Reviewed-by: Yue Haibing yuehaibing@huawei.com Reviewed-by: Xiu Jianfeng xiujianfeng@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- net/sctp/input.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/sctp/input.c b/net/sctp/input.c index ddb5b5c2550e..49c49a4d203f 100644 --- a/net/sctp/input.c +++ b/net/sctp/input.c @@ -1168,6 +1168,9 @@ 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);