From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xin Long Date: Thu, 26 Apr 2018 06:13:57 +0000 Subject: [PATCH net] sctp: handle two v4 addrs comparison in sctp_inet6_cmp_addr Message-Id: <17bfe46d7b9941f2283043f45ea5644c166c32c3.1524723237.git.lucien.xin@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: network dev , linux-sctp@vger.kernel.org Cc: davem@davemloft.net, Marcelo Ricardo Leitner , Neil Horman , syzkaller@googlegroups.com 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 --- net/sctp/ipv6.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c index 2e3f7b7..4224711 100644 --- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -895,6 +895,9 @@ 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); } -- 2.1.0