From 1071ec9d453a38023579714b64a951a2fb982071 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Thu, 12 Apr 2018 14:24:31 +0800 Subject: [PATCH] sctp: do not check port in sctp_inet6_cmp_addr pf->cmp_addr() is called before binding a v6 address to the sock. It should not check ports, like in sctp_inet_cmp_addr. But sctp_inet6_cmp_addr checks the addr by invoking af(6)->cmp_addr, sctp_v6_cmp_addr where it also compares the ports. This would cause that setsockopt(SCTP_SOCKOPT_BINDX_ADD) could bind multiple duplicated IPv6 addresses after Commit 40b4f0fd74e4 ("sctp: lack the check for ports in sctp_v6_cmp_addr"). This patch is to remove af->cmp_addr called in sctp_inet6_cmp_addr, but do the proper check for both v6 addrs and v4mapped addrs. v1->v2: - define __sctp_v6_cmp_addr to do the common address comparison used for both pf and af v6 cmp_addr. Fixes: 40b4f0fd74e4 ("sctp: lack the check for ports in sctp_v6_cmp_addr") Reported-by: Jianwen Ji Signed-off-by: Xin Long Acked-by: Neil Horman Signed-off-by: David S. Miller --- net/sctp/ipv6.c | 74 ++++++++++++++++++++++++------------------------- 1 file changed, 37 insertions(+), 37 deletions(-) diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c index 31083b5035ec..2e3f7b75a8ec 100644 --- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -556,44 +556,47 @@ static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, addr->v6.sin6_scope_id = 0; } +static int __sctp_v6_cmp_addr(const union sctp_addr *addr1, + const union sctp_addr *addr2) +{ + if (addr1->sa.sa_family != addr2->sa.sa_family) { + if (addr1->sa.sa_family == AF_INET && + addr2->sa.sa_family == AF_INET6 && + ipv6_addr_v4mapped(&addr2->v6.sin6_addr) && + addr2->v6.sin6_addr.s6_addr32[3] == + addr1->v4.sin_addr.s_addr) + return 1; + + if (addr2->sa.sa_family == AF_INET && + addr1->sa.sa_family == AF_INET6 && + ipv6_addr_v4mapped(&addr1->v6.sin6_addr) && + addr1->v6.sin6_addr.s6_addr32[3] == + addr2->v4.sin_addr.s_addr) + return 1; + + return 0; + } + + if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr)) + return 0; + + /* If this is a linklocal address, compare the scope_id. */ + if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) && + addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id && + addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id) + return 0; + + return 1; +} + /* Compare addresses exactly. * v4-mapped-v6 is also in consideration. */ static int sctp_v6_cmp_addr(const union sctp_addr *addr1, const union sctp_addr *addr2) { - if (addr1->sa.sa_family != addr2->sa.sa_family) { - if (addr1->sa.sa_family == AF_INET && - addr2->sa.sa_family == AF_INET6 && - ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) { - if (addr2->v6.sin6_port == addr1->v4.sin_port && - addr2->v6.sin6_addr.s6_addr32[3] == - addr1->v4.sin_addr.s_addr) - return 1; - } - if (addr2->sa.sa_family == AF_INET && - addr1->sa.sa_family == AF_INET6 && - ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) { - if (addr1->v6.sin6_port == addr2->v4.sin_port && - addr1->v6.sin6_addr.s6_addr32[3] == - addr2->v4.sin_addr.s_addr) - return 1; - } - return 0; - } - if (addr1->v6.sin6_port != addr2->v6.sin6_port) - return 0; - if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr)) - return 0; - /* If this is a linklocal address, compare the scope_id. */ - if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) { - if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id && - (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) { - return 0; - } - } - - return 1; + return __sctp_v6_cmp_addr(addr1, addr2) && + addr1->v6.sin6_port == addr2->v6.sin6_port; } /* Initialize addr struct to INADDR_ANY. */ @@ -875,8 +878,8 @@ static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, const union sctp_addr *addr2, struct sctp_sock *opt) { - struct sctp_af *af1, *af2; struct sock *sk = sctp_opt2sk(opt); + struct sctp_af *af1, *af2; af1 = sctp_get_af_specific(addr1->sa.sa_family); af2 = sctp_get_af_specific(addr2->sa.sa_family); @@ -892,10 +895,7 @@ 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 != addr2->sa.sa_family) - return 0; - - return af1->cmp_addr(addr1, addr2); + return __sctp_v6_cmp_addr(addr1, addr2); } /* Verify that the provided sockaddr looks bindable. Common verification,