diff options
| author | Xin Long <lucien.xin@gmail.com> | 2018-01-15 17:02:00 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-01-16 14:24:20 -0500 |
| commit | c5006b8aa74599ce19104b31d322d2ea9ff887cc (patch) | |
| tree | 116feac3332f40168ff3ba971256564bcb9b2b3f /net/sctp | |
| parent | a0ff660058b88d12625a783ce9e5c1371c87951f (diff) | |
sctp: do not allow the v4 socket to bind a v4mapped v6 address
The check in sctp_sockaddr_af is not robust enough to forbid binding a
v4mapped v6 addr on a v4 socket.
The worse thing is that v4 socket's bind_verify would not convert this
v4mapped v6 addr to a v4 addr. syzbot even reported a crash as the v4
socket bound a v6 addr.
This patch is to fix it by doing the common sa.sa_family check first,
then AF_INET check for v4mapped v6 addrs.
Fixes: 7dab83de50c7 ("sctp: Support ipv6only AF_INET6 sockets.")
Reported-by: syzbot+7b7b518b1228d2743963@syzkaller.appspotmail.com
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sctp')
| -rw-r--r-- | net/sctp/socket.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/net/sctp/socket.c b/net/sctp/socket.c index feb2ca69827a..039fcb618c34 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -335,16 +335,14 @@ static struct sctp_af *sctp_sockaddr_af(struct sctp_sock *opt, if (len < sizeof (struct sockaddr)) return NULL; + if (!opt->pf->af_supported(addr->sa.sa_family, opt)) + return NULL; + /* V4 mapped address are really of AF_INET family */ if (addr->sa.sa_family == AF_INET6 && - ipv6_addr_v4mapped(&addr->v6.sin6_addr)) { - if (!opt->pf->af_supported(AF_INET, opt)) - return NULL; - } else { - /* Does this PF support this AF? */ - if (!opt->pf->af_supported(addr->sa.sa_family, opt)) - return NULL; - } + ipv6_addr_v4mapped(&addr->v6.sin6_addr) && + !opt->pf->af_supported(AF_INET, opt)) + return NULL; /* If we get this far, af is valid. */ af = sctp_get_af_specific(addr->sa.sa_family); |