| From: Xin Long <lucien.xin@gmail.com> |
| Date: Thu, 26 Apr 2018 14:13:57 +0800 |
| Subject: sctp: handle two v4 addrs comparison in sctp_inet6_cmp_addr |
| |
| commit d625329b06e46bd20baf9ee40847d11982569204 upstream. |
| |
| 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 <lucien.xin@gmail.com> |
| Acked-by: Neil Horman <nhorman@tuxdriver.com> |
| Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| net/sctp/ipv6.c | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| --- a/net/sctp/ipv6.c |
| +++ b/net/sctp/ipv6.c |
| @@ -840,6 +840,9 @@ static int sctp_inet6_cmp_addr(const uni |
| 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); |
| } |
| |