From f9a670e10d274274fda7fd74220dfd1048dd332e Mon Sep 17 00:00:00 2001 From: Xin Long Date: Thu, 26 Apr 2018 14:13:57 +0800 Subject: [PATCH] sctp: handle two v4 addrs comparison in sctp_inet6_cmp_addr [ Upstream commit d625329b06e46bd20baf9ee40847d11982569204 ] Since sctp ipv6 socket also supports v4 addrs, it's possible to compare two v4 addrs in pf v6 .cmp_addr, sctp_inet6_cmp_addr. However after Commit 1071ec9d453a ("sctp: do not check port in sctp_inet6_cmp_addr"), it no longer calls af1->cmp_addr, which in this case is sctp_v4_cmp_addr, but calls __sctp_v6_cmp_addr where it handles them as two v6 addrs. It would cause a out of bounds crash. syzbot found this crash when trying to bind two v4 addrs to a v6 socket. This patch fixes it by adding the process for two v4 addrs in sctp_inet6_cmp_addr. Fixes: 1071ec9d453a ("sctp: do not check port in sctp_inet6_cmp_addr") Reported-by: syzbot+cd494c1dd681d4d93ebb@syzkaller.appspotmail.com Signed-off-by: Xin Long Acked-by: Neil Horman Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sctp/ipv6.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c index e031797ad311..f4d5efb1d231 100644 --- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -864,6 +864,9 @@ static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) return 1; + if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET) + return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr; + return __sctp_v6_cmp_addr(addr1, addr2); } -- 2.20.1