Commit message: ipv6_sockglue: Fix a missing-check bug in ip6_ra_control()

In function ip6_ra_control(), the pointer new_ra is allocated a memory
space via kmalloc(). And it is used in the following codes. However,
when there is a memory allocation error, kmalloc() fails. Thus null
pointer dereference may happen. And it will cause the kernel to crash.
Therefore, we should check the return value and handle the error.

Signed-off-by: Gen Zhang <blackgod016574@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
CVE: CVE-2019-12378
CWE: CWE-476
Vulnerability description: An issue was discovered in ip6_ra_control in net/ipv6/ipv6_sockglue.c in the Linux kernel through 5.1.5. There is an unchecked kmalloc of new_ra, which might allow an attacker to cause a denial of service (NULL pointer dereference and system crash). NOTE: This has been disputed as not an issue

Project: net
File: ipv6_sockglue.c

static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
		    char __user *optval, int __user *optlen, unsigned int flags)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	int len;
	int val;

	if (ip6_mroute_opt(optname))
		return ip6_mroute_getsockopt(sk, optname, optval, optlen);

	if (get_user(len, optlen))
		return -EFAULT;
	switch (optname) {
	case IPV6_ADDRFORM:
		if (sk->sk_protocol != IPPROTO_UDP &&
		    sk->sk_protocol != IPPROTO_UDPLITE &&
		    sk->sk_protocol != IPPROTO_TCP)
			return -ENOPROTOOPT;
		if (sk->sk_state != TCP_ESTABLISHED)
			return -ENOTCONN;
		val = sk->sk_family;
		break;
	case MCAST_MSFILTER:
	{
		struct group_filter gsf;
		int err;

		if (len < GROUP_FILTER_SIZE(0))
			return -EINVAL;
		if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0)))
			return -EFAULT;
		if (gsf.gf_group.ss_family != AF_INET6)
			return -EADDRNOTAVAIL;
		lock_sock(sk);
		err = ip6_mc_msfget(sk, &gsf,
			(struct group_filter __user *)optval, optlen);
		release_sock(sk);
		return err;
	}

	case IPV6_2292PKTOPTIONS:
	{
		struct msghdr msg;
		struct sk_buff *skb;

		if (sk->sk_type != SOCK_STREAM)
			return -ENOPROTOOPT;

		msg.msg_control = optval;
		msg.msg_controllen = len;
		msg.msg_flags = flags;

		lock_sock(sk);
		skb = np->pktoptions;
		if (skb)
			ip6_datagram_recv_ctl(sk, &msg, skb);
		release_sock(sk);
		if (!skb) {
			if (np->rxopt.bits.rxinfo) {
				struct in6_pktinfo src_info;
				src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif :
					np->sticky_pktinfo.ipi6_ifindex;
				src_info.ipi6_addr = np->mcast_oif ? sk->sk_v6_daddr : np->sticky_pktinfo.ipi6_addr;
				put_cmsg(&msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
			}
			if (np->rxopt.bits.rxhlim) {
				int hlim = np->mcast_hops;
				put_cmsg(&msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
			}
			if (np->rxopt.bits.rxtclass) {
				int tclass = (int)ip6_tclass(np->rcv_flowinfo);

				put_cmsg(&msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
			}
			if (np->rxopt.bits.rxoinfo) {
				struct in6_pktinfo src_info;
				src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif :
					np->sticky_pktinfo.ipi6_ifindex;
				src_info.ipi6_addr = np->mcast_oif ? sk->sk_v6_daddr :
								     np->sticky_pktinfo.ipi6_addr;
				put_cmsg(&msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
			}
			if (np->rxopt.bits.rxohlim) {
				int hlim = np->mcast_hops;
				put_cmsg(&msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
			}
			if (np->rxopt.bits.rxflow) {
				__be32 flowinfo = np->rcv_flowinfo;

				put_cmsg(&msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
			}
		}
		len -= msg.msg_controllen;
		return put_user(len, optlen);
	}
	case IPV6_MTU:
	{
		struct dst_entry *dst;

		val = 0;
		rcu_read_lock();
		dst = __sk_dst_get(sk);
		if (dst)
			val = dst_mtu(dst);
		rcu_read_unlock();
		if (!val)
			return -ENOTCONN;
		break;
	}

	case IPV6_V6ONLY:
		val = sk->sk_ipv6only;
		break;

	case IPV6_RECVPKTINFO:
		val = np->rxopt.bits.rxinfo;
		break;

	case IPV6_2292PKTINFO:
		val = np->rxopt.bits.rxoinfo;
		break;

	case IPV6_RECVHOPLIMIT:
		val = np->rxopt.bits.rxhlim;
		break;

	case IPV6_2292HOPLIMIT:
		val = np->rxopt.bits.rxohlim;
		break;

	case IPV6_RECVRTHDR:
		val = np->rxopt.bits.srcrt;
		break;

	case IPV6_2292RTHDR:
		val = np->rxopt.bits.osrcrt;
		break;

	case IPV6_HOPOPTS:
	case IPV6_RTHDRDSTOPTS:
	case IPV6_RTHDR:
	case IPV6_DSTOPTS:
	{
		struct ipv6_txoptions *opt;

		lock_sock(sk);
		opt = rcu_dereference_protected(np->opt,
						lockdep_sock_is_held(sk));
		len = ipv6_getsockopt_sticky(sk, opt, optname, optval, len);
		release_sock(sk);
		/* check if ipv6_getsockopt_sticky() returns err code */
		if (len < 0)
			return len;
		return put_user(len, optlen);
	}

	case IPV6_RECVHOPOPTS:
		val = np->rxopt.bits.hopopts;
		break;

	case IPV6_2292HOPOPTS:
		val = np->rxopt.bits.ohopopts;
		break;

	case IPV6_RECVDSTOPTS:
		val = np->rxopt.bits.dstopts;
		break;

	case IPV6_2292DSTOPTS:
		val = np->rxopt.bits.odstopts;
		break;

	case IPV6_TCLASS:
		val = np->tclass;
		break;

	case IPV6_RECVTCLASS:
		val = np->rxopt.bits.rxtclass;
		break;

	case IPV6_FLOWINFO:
		val = np->rxopt.bits.rxflow;
		break;

	case IPV6_RECVPATHMTU:
		val = np->rxopt.bits.rxpmtu;
		break;

	case IPV6_PATHMTU:
	{
		struct dst_entry *dst;
		struct ip6_mtuinfo mtuinfo;

		if (len < sizeof(mtuinfo))
			return -EINVAL;

		len = sizeof(mtuinfo);
		memset(&mtuinfo, 0, sizeof(mtuinfo));

		rcu_read_lock();
		dst = __sk_dst_get(sk);
		if (dst)
			mtuinfo.ip6m_mtu = dst_mtu(dst);
		rcu_read_unlock();
		if (!mtuinfo.ip6m_mtu)
			return -ENOTCONN;

		if (put_user(len, optlen))
			return -EFAULT;
		if (copy_to_user(optval, &mtuinfo, len))
			return -EFAULT;

		return 0;
	}

	case IPV6_TRANSPARENT:
		val = inet_sk(sk)->transparent;
		break;

	case IPV6_FREEBIND:
		val = inet_sk(sk)->freebind;
		break;

	case IPV6_RECVORIGDSTADDR:
		val = np->rxopt.bits.rxorigdstaddr;
		break;

	case IPV6_UNICAST_HOPS:
	case IPV6_MULTICAST_HOPS:
	{
		struct dst_entry *dst;

		if (optname == IPV6_UNICAST_HOPS)
			val = np->hop_limit;
		else
			val = np->mcast_hops;

		if (val < 0) {
			rcu_read_lock();
			dst = __sk_dst_get(sk);
			if (dst)
				val = ip6_dst_hoplimit(dst);
			rcu_read_unlock();
		}

		if (val < 0)
			val = sock_net(sk)->ipv6.devconf_all->hop_limit;
		break;
	}

	case IPV6_MULTICAST_LOOP:
		val = np->mc_loop;
		break;

	case IPV6_MULTICAST_IF:
		val = np->mcast_oif;
		break;

	case IPV6_MULTICAST_ALL:
		val = np->mc_all;
		break;

	case IPV6_UNICAST_IF:
		val = (__force int)htonl((__u32) np->ucast_oif);
		break;

	case IPV6_MTU_DISCOVER:
		val = np->pmtudisc;
		break;

	case IPV6_RECVERR:
		val = np->recverr;
		break;

	case IPV6_FLOWINFO_SEND:
		val = np->sndflow;
		break;

	case IPV6_FLOWLABEL_MGR:
	{
		struct in6_flowlabel_req freq;
		int flags;

		if (len < sizeof(freq))
			return -EINVAL;

		if (copy_from_user(&freq, optval, sizeof(freq)))
			return -EFAULT;

		if (freq.flr_action != IPV6_FL_A_GET)
			return -EINVAL;

		len = sizeof(freq);
		flags = freq.flr_flags;

		memset(&freq, 0, sizeof(freq));

		val = ipv6_flowlabel_opt_get(sk, &freq, flags);
		if (val < 0)
			return val;

		if (put_user(len, optlen))
			return -EFAULT;
		if (copy_to_user(optval, &freq, len))
			return -EFAULT;

		return 0;
	}

	case IPV6_ADDR_PREFERENCES:
		val = 0;

		if (np->srcprefs & IPV6_PREFER_SRC_TMP)
			val |= IPV6_PREFER_SRC_TMP;
		else if (np->srcprefs & IPV6_PREFER_SRC_PUBLIC)
			val |= IPV6_PREFER_SRC_PUBLIC;
		else {
			/* XXX: should we return system default? */
			val |= IPV6_PREFER_SRC_PUBTMP_DEFAULT;
		}

		if (np->srcprefs & IPV6_PREFER_SRC_COA)
			val |= IPV6_PREFER_SRC_COA;
		else
			val |= IPV6_PREFER_SRC_HOME;
		break;

	case IPV6_MINHOPCOUNT:
		val = np->min_hopcount;
		break;

	case IPV6_DONTFRAG:
		val = np->dontfrag;
		break;

	case IPV6_AUTOFLOWLABEL:
		val = ip6_autoflowlabel(sock_net(sk), np);
		break;

	case IPV6_RECVFRAGSIZE:
		val = np->rxopt.bits.recvfragsize;
		break;

	case IPV6_ROUTER_ALERT_ISOLATE:
		val = np->rtalert_isolate;
		break;

	default:
		return -ENOPROTOOPT;
	}
	len = min_t(unsigned int, sizeof(int), len);
	if (put_user(len, optlen))
		return -EFAULT;
	if (copy_to_user(optval, &val, len))
		return -EFAULT;
	return 0;
}

Project: net
File: ipv6_sockglue.c

int ipv6_getsockopt(struct sock *sk, int level, int optname,
		    char __user *optval, int __user *optlen)
{
	int err;

	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
		return udp_prot.getsockopt(sk, level, optname, optval, optlen);

	if (level != SOL_IPV6)
		return -ENOPROTOOPT;

	err = do_ipv6_getsockopt(sk, level, optname, optval, optlen, 0);
#ifdef CONFIG_NETFILTER
	/* we need to exclude all possible ENOPROTOOPTs except default case */
	if (err == -ENOPROTOOPT && optname != IPV6_2292PKTOPTIONS) {
		int len;

		if (get_user(len, optlen))
			return -EFAULT;

		err = nf_getsockopt(sk, PF_INET6, optname, optval, &len);
		if (err >= 0)
			err = put_user(len, optlen);
	}
#endif
	return err;
}

Project: net
File: ipv6_sockglue.c

struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
					   struct ipv6_txoptions *opt)
{
	if (inet_sk(sk)->is_icsk) {
		if (opt &&
		    !((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) &&
		    inet_sk(sk)->inet_daddr != LOOPBACK4_IPV6) {
			struct inet_connection_sock *icsk = inet_csk(sk);
			icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
			icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
		}
	}
	opt = xchg((__force struct ipv6_txoptions **)&inet6_sk(sk)->opt,
		   opt);
	sk_dst_reset(sk);

	return opt;
}

Project: net
File: ipv6_sockglue.c

int ipv6_setsockopt(struct sock *sk, int level, int optname,
		    char __user *optval, unsigned int optlen)
{
	int err;

	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
		return udp_prot.setsockopt(sk, level, optname, optval, optlen);

	if (level != SOL_IPV6)
		return -ENOPROTOOPT;

	err = do_ipv6_setsockopt(sk, level, optname, optval, optlen);
#ifdef CONFIG_NETFILTER
	/* we need to exclude all possible ENOPROTOOPTs except default case */
	if (err == -ENOPROTOOPT && optname != IPV6_IPSEC_POLICY &&
			optname != IPV6_XFRM_POLICY)
		err = nf_setsockopt(sk, PF_INET6, optname, optval, optlen);
#endif
	return err;
}

Project: net
File: ipv6_sockglue.c

int ip6_ra_control(struct sock *sk, int sel)
{
	struct ip6_ra_chain *ra, *new_ra, **rap;

	/* RA packet may be delivered ONLY to IPPROTO_RAW socket */
	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num != IPPROTO_RAW)
		return -ENOPROTOOPT;

	new_ra = (sel >= 0) ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
	if (sel >= 0 && !new_ra)
		return -ENOMEM;

	write_lock_bh(&ip6_ra_lock);
	for (rap = &ip6_ra_chain; (ra = *rap) != NULL; rap = &ra->next) {
		if (ra->sk == sk) {
			if (sel >= 0) {
				write_unlock_bh(&ip6_ra_lock);
				kfree(new_ra);
				return -EADDRINUSE;
			}

			*rap = ra->next;
			write_unlock_bh(&ip6_ra_lock);

			sock_put(sk);
			kfree(ra);
			return 0;
		}
	}
	if (!new_ra) {
		write_unlock_bh(&ip6_ra_lock);
		return -ENOBUFS;
	}
	new_ra->sk = sk;
	new_ra->sel = sel;
	new_ra->next = ra;
	*rap = new_ra;
	sock_hold(sk);
	write_unlock_bh(&ip6_ra_lock);
	return 0;
}

Project: net
File: ipv6_sockglue.c

static bool setsockopt_needs_rtnl(int optname)
{
	switch (optname) {
	case IPV6_ADDRFORM:
	case IPV6_ADD_MEMBERSHIP:
	case IPV6_DROP_MEMBERSHIP:
	case IPV6_JOIN_ANYCAST:
	case IPV6_LEAVE_ANYCAST:
	case MCAST_JOIN_GROUP:
	case MCAST_LEAVE_GROUP:
	case MCAST_JOIN_SOURCE_GROUP:
	case MCAST_LEAVE_SOURCE_GROUP:
	case MCAST_BLOCK_SOURCE:
	case MCAST_UNBLOCK_SOURCE:
	case MCAST_MSFILTER:
		return true;
	}
	return false;
}

Project: net
File: ipv6_sockglue.c

int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
			   char __user *optval, unsigned int optlen)
{
	int err;

	if (level == SOL_IP && sk->sk_type != SOCK_RAW) {
		if (udp_prot.compat_setsockopt != NULL)
			return udp_prot.compat_setsockopt(sk, level, optname,
							  optval, optlen);
		return udp_prot.setsockopt(sk, level, optname, optval, optlen);
	}

	if (level != SOL_IPV6)
		return -ENOPROTOOPT;

	if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
		return compat_mc_setsockopt(sk, level, optname, optval, optlen,
			ipv6_setsockopt);

	err = do_ipv6_setsockopt(sk, level, optname, optval, optlen);
#ifdef CONFIG_NETFILTER
	/* we need to exclude all possible ENOPROTOOPTs except default case */
	if (err == -ENOPROTOOPT && optname != IPV6_IPSEC_POLICY &&
	    optname != IPV6_XFRM_POLICY)
		err = compat_nf_setsockopt(sk, PF_INET6, optname, optval,
					   optlen);
#endif
	return err;
}

Project: net
File: ipv6_sockglue.c

int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
			   char __user *optval, int __user *optlen)
{
	int err;

	if (level == SOL_IP && sk->sk_type != SOCK_RAW) {
		if (udp_prot.compat_getsockopt != NULL)
			return udp_prot.compat_getsockopt(sk, level, optname,
							  optval, optlen);
		return udp_prot.getsockopt(sk, level, optname, optval, optlen);
	}

	if (level != SOL_IPV6)
		return -ENOPROTOOPT;

	if (optname == MCAST_MSFILTER)
		return compat_mc_getsockopt(sk, level, optname, optval, optlen,
			ipv6_getsockopt);

	err = do_ipv6_getsockopt(sk, level, optname, optval, optlen,
				 MSG_CMSG_COMPAT);
#ifdef CONFIG_NETFILTER
	/* we need to exclude all possible ENOPROTOOPTs except default case */
	if (err == -ENOPROTOOPT && optname != IPV6_2292PKTOPTIONS) {
		int len;

		if (get_user(len, optlen))
			return -EFAULT;

		err = compat_nf_getsockopt(sk, PF_INET6, optname, optval, &len);
		if (err >= 0)
			err = put_user(len, optlen);
	}
#endif
	return err;
}

Project: net
File: ipv6_sockglue.c

static int ipv6_getsockopt_sticky(struct sock *sk, struct ipv6_txoptions *opt,
				  int optname, char __user *optval, int len)
{
	struct ipv6_opt_hdr *hdr;

	if (!opt)
		return 0;

	switch (optname) {
	case IPV6_HOPOPTS:
		hdr = opt->hopopt;
		break;
	case IPV6_RTHDRDSTOPTS:
		hdr = opt->dst0opt;
		break;
	case IPV6_RTHDR:
		hdr = (struct ipv6_opt_hdr *)opt->srcrt;
		break;
	case IPV6_DSTOPTS:
		hdr = opt->dst1opt;
		break;
	default:
		return -EINVAL;	/* should not happen */
	}

	if (!hdr)
		return 0;

	len = min_t(unsigned int, len, ipv6_optlen(hdr));
	if (copy_to_user(optval, hdr, len))
		return -EFAULT;
	return len;
}

Project: net
File: ipv6_sockglue.c

static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
		    char __user *optval, unsigned int optlen)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct net *net = sock_net(sk);
	int val, valbool;
	int retv = -ENOPROTOOPT;
	bool needs_rtnl = setsockopt_needs_rtnl(optname);

	if (!optval)
		val = 0;
	else {
		if (optlen >= sizeof(int)) {
			if (get_user(val, (int __user *) optval))
				return -EFAULT;
		} else
			val = 0;
	}

	valbool = (val != 0);

	if (ip6_mroute_opt(optname))
		return ip6_mroute_setsockopt(sk, optname, optval, optlen);

	if (needs_rtnl)
		rtnl_lock();
	lock_sock(sk);

	switch (optname) {

	case IPV6_ADDRFORM:
		if (optlen < sizeof(int))
			goto e_inval;
		if (val == PF_INET) {
			struct ipv6_txoptions *opt;
			struct sk_buff *pktopt;

			if (sk->sk_type == SOCK_RAW)
				break;

			if (sk->sk_protocol == IPPROTO_UDP ||
			    sk->sk_protocol == IPPROTO_UDPLITE) {
				struct udp_sock *up = udp_sk(sk);
				if (up->pending == AF_INET6) {
					retv = -EBUSY;
					break;
				}
			} else if (sk->sk_protocol != IPPROTO_TCP)
				break;

			if (sk->sk_state != TCP_ESTABLISHED) {
				retv = -ENOTCONN;
				break;
			}

			if (ipv6_only_sock(sk) ||
			    !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) {
				retv = -EADDRNOTAVAIL;
				break;
			}

			fl6_free_socklist(sk);
			__ipv6_sock_mc_close(sk);

			/*
			 * Sock is moving from IPv6 to IPv4 (sk_prot), so
			 * remove it from the refcnt debug socks count in the
			 * original family...
			 */
			sk_refcnt_debug_dec(sk);

			if (sk->sk_protocol == IPPROTO_TCP) {
				struct inet_connection_sock *icsk = inet_csk(sk);
				local_bh_disable();
				sock_prot_inuse_add(net, sk->sk_prot, -1);
				sock_prot_inuse_add(net, &tcp_prot, 1);
				local_bh_enable();
				sk->sk_prot = &tcp_prot;
				icsk->icsk_af_ops = &ipv4_specific;
				sk->sk_socket->ops = &inet_stream_ops;
				sk->sk_family = PF_INET;
				tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
			} else {
				struct proto *prot = &udp_prot;

				if (sk->sk_protocol == IPPROTO_UDPLITE)
					prot = &udplite_prot;
				local_bh_disable();
				sock_prot_inuse_add(net, sk->sk_prot, -1);
				sock_prot_inuse_add(net, prot, 1);
				local_bh_enable();
				sk->sk_prot = prot;
				sk->sk_socket->ops = &inet_dgram_ops;
				sk->sk_family = PF_INET;
			}
			opt = xchg((__force struct ipv6_txoptions **)&np->opt,
				   NULL);
			if (opt) {
				atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
				txopt_put(opt);
			}
			pktopt = xchg(&np->pktoptions, NULL);
			kfree_skb(pktopt);

			/*
			 * ... and add it to the refcnt debug socks count
			 * in the new family. -acme
			 */
			sk_refcnt_debug_inc(sk);
			module_put(THIS_MODULE);
			retv = 0;
			break;
		}
		goto e_inval;

	case IPV6_V6ONLY:
		if (optlen < sizeof(int) ||
		    inet_sk(sk)->inet_num)
			goto e_inval;
		sk->sk_ipv6only = valbool;
		retv = 0;
		break;

	case IPV6_RECVPKTINFO:
		if (optlen < sizeof(int))
			goto e_inval;
		np->rxopt.bits.rxinfo = valbool;
		retv = 0;
		break;

	case IPV6_2292PKTINFO:
		if (optlen < sizeof(int))
			goto e_inval;
		np->rxopt.bits.rxoinfo = valbool;
		retv = 0;
		break;

	case IPV6_RECVHOPLIMIT:
		if (optlen < sizeof(int))
			goto e_inval;
		np->rxopt.bits.rxhlim = valbool;
		retv = 0;
		break;

	case IPV6_2292HOPLIMIT:
		if (optlen < sizeof(int))
			goto e_inval;
		np->rxopt.bits.rxohlim = valbool;
		retv = 0;
		break;

	case IPV6_RECVRTHDR:
		if (optlen < sizeof(int))
			goto e_inval;
		np->rxopt.bits.srcrt = valbool;
		retv = 0;
		break;

	case IPV6_2292RTHDR:
		if (optlen < sizeof(int))
			goto e_inval;
		np->rxopt.bits.osrcrt = valbool;
		retv = 0;
		break;

	case IPV6_RECVHOPOPTS:
		if (optlen < sizeof(int))
			goto e_inval;
		np->rxopt.bits.hopopts = valbool;
		retv = 0;
		break;

	case IPV6_2292HOPOPTS:
		if (optlen < sizeof(int))
			goto e_inval;
		np->rxopt.bits.ohopopts = valbool;
		retv = 0;
		break;

	case IPV6_RECVDSTOPTS:
		if (optlen < sizeof(int))
			goto e_inval;
		np->rxopt.bits.dstopts = valbool;
		retv = 0;
		break;

	case IPV6_2292DSTOPTS:
		if (optlen < sizeof(int))
			goto e_inval;
		np->rxopt.bits.odstopts = valbool;
		retv = 0;
		break;

	case IPV6_TCLASS:
		if (optlen < sizeof(int))
			goto e_inval;
		if (val < -1 || val > 0xff)
			goto e_inval;
		/* RFC 3542, 6.5: default traffic class of 0x0 */
		if (val == -1)
			val = 0;
		np->tclass = val;
		retv = 0;
		break;

	case IPV6_RECVTCLASS:
		if (optlen < sizeof(int))
			goto e_inval;
		np->rxopt.bits.rxtclass = valbool;
		retv = 0;
		break;

	case IPV6_FLOWINFO:
		if (optlen < sizeof(int))
			goto e_inval;
		np->rxopt.bits.rxflow = valbool;
		retv = 0;
		break;

	case IPV6_RECVPATHMTU:
		if (optlen < sizeof(int))
			goto e_inval;
		np->rxopt.bits.rxpmtu = valbool;
		retv = 0;
		break;

	case IPV6_TRANSPARENT:
		if (valbool && !ns_capable(net->user_ns, CAP_NET_ADMIN) &&
		    !ns_capable(net->user_ns, CAP_NET_RAW)) {
			retv = -EPERM;
			break;
		}
		if (optlen < sizeof(int))
			goto e_inval;
		/* we don't have a separate transparent bit for IPV6 we use the one in the IPv4 socket */
		inet_sk(sk)->transparent = valbool;
		retv = 0;
		break;

	case IPV6_FREEBIND:
		if (optlen < sizeof(int))
			goto e_inval;
		/* we also don't have a separate freebind bit for IPV6 */
		inet_sk(sk)->freebind = valbool;
		retv = 0;
		break;

	case IPV6_RECVORIGDSTADDR:
		if (optlen < sizeof(int))
			goto e_inval;
		np->rxopt.bits.rxorigdstaddr = valbool;
		retv = 0;
		break;

	case IPV6_HOPOPTS:
	case IPV6_RTHDRDSTOPTS:
	case IPV6_RTHDR:
	case IPV6_DSTOPTS:
	{
		struct ipv6_txoptions *opt;
		struct ipv6_opt_hdr *new = NULL;

		/* hop-by-hop / destination options are privileged option */
		retv = -EPERM;
		if (optname != IPV6_RTHDR && !ns_capable(net->user_ns, CAP_NET_RAW))
			break;

		/* remove any sticky options header with a zero option
		 * length, per RFC3542.
		 */
		if (optlen == 0)
			optval = NULL;
		else if (!optval)
			goto e_inval;
		else if (optlen < sizeof(struct ipv6_opt_hdr) ||
			 optlen & 0x7 || optlen > 8 * 255)
			goto e_inval;
		else {
			new = memdup_user(optval, optlen);
			if (IS_ERR(new)) {
				retv = PTR_ERR(new);
				break;
			}
			if (unlikely(ipv6_optlen(new) > optlen)) {
				kfree(new);
				goto e_inval;
			}
		}

		opt = rcu_dereference_protected(np->opt,
						lockdep_sock_is_held(sk));
		opt = ipv6_renew_options(sk, opt, optname, new);
		kfree(new);
		if (IS_ERR(opt)) {
			retv = PTR_ERR(opt);
			break;
		}

		/* routing header option needs extra check */
		retv = -EINVAL;
		if (optname == IPV6_RTHDR && opt && opt->srcrt) {
			struct ipv6_rt_hdr *rthdr = opt->srcrt;
			switch (rthdr->type) {
#if IS_ENABLED(CONFIG_IPV6_MIP6)
			case IPV6_SRCRT_TYPE_2:
				if (rthdr->hdrlen != 2 ||
				    rthdr->segments_left != 1)
					goto sticky_done;

				break;
#endif
			case IPV6_SRCRT_TYPE_4:
			{
				struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)
							  opt->srcrt;

				if (!seg6_validate_srh(srh, optlen))
					goto sticky_done;
				break;
			}
			default:
				goto sticky_done;
			}
		}

		retv = 0;
		opt = ipv6_update_options(sk, opt);
sticky_done:
		if (opt) {
			atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
			txopt_put(opt);
		}
		break;
	}

	case IPV6_PKTINFO:
	{
		struct in6_pktinfo pkt;

		if (optlen == 0)
			goto e_inval;
		else if (optlen < sizeof(struct in6_pktinfo) || !optval)
			goto e_inval;

		if (copy_from_user(&pkt, optval, sizeof(struct in6_pktinfo))) {
				retv = -EFAULT;
				break;
		}
		if (!sk_dev_equal_l3scope(sk, pkt.ipi6_ifindex))
			goto e_inval;

		np->sticky_pktinfo.ipi6_ifindex = pkt.ipi6_ifindex;
		np->sticky_pktinfo.ipi6_addr = pkt.ipi6_addr;
		retv = 0;
		break;
	}

	case IPV6_2292PKTOPTIONS:
	{
		struct ipv6_txoptions *opt = NULL;
		struct msghdr msg;
		struct flowi6 fl6;
		struct ipcm6_cookie ipc6;

		memset(&fl6, 0, sizeof(fl6));
		fl6.flowi6_oif = sk->sk_bound_dev_if;
		fl6.flowi6_mark = sk->sk_mark;

		if (optlen == 0)
			goto update;

		/* 1K is probably excessive
		 * 1K is surely not enough, 2K per standard header is 16K.
		 */
		retv = -EINVAL;
		if (optlen > 64*1024)
			break;

		opt = sock_kmalloc(sk, sizeof(*opt) + optlen, GFP_KERNEL);
		retv = -ENOBUFS;
		if (!opt)
			break;

		memset(opt, 0, sizeof(*opt));
		refcount_set(&opt->refcnt, 1);
		opt->tot_len = sizeof(*opt) + optlen;
		retv = -EFAULT;
		if (copy_from_user(opt+1, optval, optlen))
			goto done;

		msg.msg_controllen = optlen;
		msg.msg_control = (void *)(opt+1);
		ipc6.opt = opt;

		retv = ip6_datagram_send_ctl(net, sk, &msg, &fl6, &ipc6);
		if (retv)
			goto done;
update:
		retv = 0;
		opt = ipv6_update_options(sk, opt);
done:
		if (opt) {
			atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
			txopt_put(opt);
		}
		break;
	}
	case IPV6_UNICAST_HOPS:
		if (optlen < sizeof(int))
			goto e_inval;
		if (val > 255 || val < -1)
			goto e_inval;
		np->hop_limit = val;
		retv = 0;
		break;

	case IPV6_MULTICAST_HOPS:
		if (sk->sk_type == SOCK_STREAM)
			break;
		if (optlen < sizeof(int))
			goto e_inval;
		if (val > 255 || val < -1)
			goto e_inval;
		np->mcast_hops = (val == -1 ? IPV6_DEFAULT_MCASTHOPS : val);
		retv = 0;
		break;

	case IPV6_MULTICAST_LOOP:
		if (optlen < sizeof(int))
			goto e_inval;
		if (val != valbool)
			goto e_inval;
		np->mc_loop = valbool;
		retv = 0;
		break;

	case IPV6_UNICAST_IF:
	{
		struct net_device *dev = NULL;
		int ifindex;

		if (optlen != sizeof(int))
			goto e_inval;

		ifindex = (__force int)ntohl((__force __be32)val);
		if (ifindex == 0) {
			np->ucast_oif = 0;
			retv = 0;
			break;
		}

		dev = dev_get_by_index(net, ifindex);
		retv = -EADDRNOTAVAIL;
		if (!dev)
			break;
		dev_put(dev);

		retv = -EINVAL;
		if (sk->sk_bound_dev_if)
			break;

		np->ucast_oif = ifindex;
		retv = 0;
		break;
	}

	case IPV6_MULTICAST_IF:
		if (sk->sk_type == SOCK_STREAM)
			break;
		if (optlen < sizeof(int))
			goto e_inval;

		if (val) {
			struct net_device *dev;
			int midx;

			rcu_read_lock();

			dev = dev_get_by_index_rcu(net, val);
			if (!dev) {
				rcu_read_unlock();
				retv = -ENODEV;
				break;
			}
			midx = l3mdev_master_ifindex_rcu(dev);

			rcu_read_unlock();

			if (sk->sk_bound_dev_if &&
			    sk->sk_bound_dev_if != val &&
			    (!midx || midx != sk->sk_bound_dev_if))
				goto e_inval;
		}
		np->mcast_oif = val;
		retv = 0;
		break;
	case IPV6_ADD_MEMBERSHIP:
	case IPV6_DROP_MEMBERSHIP:
	{
		struct ipv6_mreq mreq;

		if (optlen < sizeof(struct ipv6_mreq))
			goto e_inval;

		retv = -EPROTO;
		if (inet_sk(sk)->is_icsk)
			break;

		retv = -EFAULT;
		if (copy_from_user(&mreq, optval, sizeof(struct ipv6_mreq)))
			break;

		if (optname == IPV6_ADD_MEMBERSHIP)
			retv = ipv6_sock_mc_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
		else
			retv = ipv6_sock_mc_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
		break;
	}
	case IPV6_JOIN_ANYCAST:
	case IPV6_LEAVE_ANYCAST:
	{
		struct ipv6_mreq mreq;

		if (optlen < sizeof(struct ipv6_mreq))
			goto e_inval;

		retv = -EFAULT;
		if (copy_from_user(&mreq, optval, sizeof(struct ipv6_mreq)))
			break;

		if (optname == IPV6_JOIN_ANYCAST)
			retv = ipv6_sock_ac_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
		else
			retv = ipv6_sock_ac_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
		break;
	}
	case IPV6_MULTICAST_ALL:
		if (optlen < sizeof(int))
			goto e_inval;
		np->mc_all = valbool;
		retv = 0;
		break;

	case MCAST_JOIN_GROUP:
	case MCAST_LEAVE_GROUP:
	{
		struct group_req greq;
		struct sockaddr_in6 *psin6;

		if (optlen < sizeof(struct group_req))
			goto e_inval;

		retv = -EFAULT;
		if (copy_from_user(&greq, optval, sizeof(struct group_req)))
			break;
		if (greq.gr_group.ss_family != AF_INET6) {
			retv = -EADDRNOTAVAIL;
			break;
		}
		psin6 = (struct sockaddr_in6 *)&greq.gr_group;
		if (optname == MCAST_JOIN_GROUP)
			retv = ipv6_sock_mc_join(sk, greq.gr_interface,
						 &psin6->sin6_addr);
		else
			retv = ipv6_sock_mc_drop(sk, greq.gr_interface,
						 &psin6->sin6_addr);
		break;
	}
	case MCAST_JOIN_SOURCE_GROUP:
	case MCAST_LEAVE_SOURCE_GROUP:
	case MCAST_BLOCK_SOURCE:
	case MCAST_UNBLOCK_SOURCE:
	{
		struct group_source_req greqs;
		int omode, add;

		if (optlen < sizeof(struct group_source_req))
			goto e_inval;
		if (copy_from_user(&greqs, optval, sizeof(greqs))) {
			retv = -EFAULT;
			break;
		}
		if (greqs.gsr_group.ss_family != AF_INET6 ||
		    greqs.gsr_source.ss_family != AF_INET6) {
			retv = -EADDRNOTAVAIL;
			break;
		}
		if (optname == MCAST_BLOCK_SOURCE) {
			omode = MCAST_EXCLUDE;
			add = 1;
		} else if (optname == MCAST_UNBLOCK_SOURCE) {
			omode = MCAST_EXCLUDE;
			add = 0;
		} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
			struct sockaddr_in6 *psin6;

			psin6 = (struct sockaddr_in6 *)&greqs.gsr_group;
			retv = ipv6_sock_mc_join_ssm(sk, greqs.gsr_interface,
						     &psin6->sin6_addr,
						     MCAST_INCLUDE);
			/* prior join w/ different source is ok */
			if (retv && retv != -EADDRINUSE)
				break;
			omode = MCAST_INCLUDE;
			add = 1;
		} else /* MCAST_LEAVE_SOURCE_GROUP */ {
			omode = MCAST_INCLUDE;
			add = 0;
		}
		retv = ip6_mc_source(add, omode, sk, &greqs);
		break;
	}
	case MCAST_MSFILTER:
	{
		struct group_filter *gsf;

		if (optlen < GROUP_FILTER_SIZE(0))
			goto e_inval;
		if (optlen > sysctl_optmem_max) {
			retv = -ENOBUFS;
			break;
		}
		gsf = memdup_user(optval, optlen);
		if (IS_ERR(gsf)) {
			retv = PTR_ERR(gsf);
			break;
		}
		/* numsrc >= (4G-140)/128 overflow in 32 bits */
		if (gsf->gf_numsrc >= 0x1ffffffU ||
		    gsf->gf_numsrc > sysctl_mld_max_msf) {
			kfree(gsf);
			retv = -ENOBUFS;
			break;
		}
		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
			kfree(gsf);
			retv = -EINVAL;
			break;
		}
		retv = ip6_mc_msfilter(sk, gsf);
		kfree(gsf);

		break;
	}
	case IPV6_ROUTER_ALERT:
		if (optlen < sizeof(int))
			goto e_inval;
		retv = ip6_ra_control(sk, val);
		break;
	case IPV6_ROUTER_ALERT_ISOLATE:
		if (optlen < sizeof(int))
			goto e_inval;
		np->rtalert_isolate = valbool;
		retv = 0;
		break;
	case IPV6_MTU_DISCOVER:
		if (optlen < sizeof(int))
			goto e_inval;
		if (val < IPV6_PMTUDISC_DONT || val > IPV6_PMTUDISC_OMIT)
			goto e_inval;
		np->pmtudisc = val;
		retv = 0;
		break;
	case IPV6_MTU:
		if (optlen < sizeof(int))
			goto e_inval;
		if (val && val < IPV6_MIN_MTU)
			goto e_inval;
		np->frag_size = val;
		retv = 0;
		break;
	case IPV6_RECVERR:
		if (optlen < sizeof(int))
			goto e_inval;
		np->recverr = valbool;
		if (!val)
			skb_queue_purge(&sk->sk_error_queue);
		retv = 0;
		break;
	case IPV6_FLOWINFO_SEND:
		if (optlen < sizeof(int))
			goto e_inval;
		np->sndflow = valbool;
		retv = 0;
		break;
	case IPV6_FLOWLABEL_MGR:
		retv = ipv6_flowlabel_opt(sk, optval, optlen);
		break;
	case IPV6_IPSEC_POLICY:
	case IPV6_XFRM_POLICY:
		retv = -EPERM;
		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
			break;
		retv = xfrm_user_policy(sk, optname, optval, optlen);
		break;

	case IPV6_ADDR_PREFERENCES:
	    {
		unsigned int pref = 0;
		unsigned int prefmask = ~0;

		if (optlen < sizeof(int))
			goto e_inval;

		retv = -EINVAL;

		/* check PUBLIC/TMP/PUBTMP_DEFAULT conflicts */
		switch (val & (IPV6_PREFER_SRC_PUBLIC|
			       IPV6_PREFER_SRC_TMP|
			       IPV6_PREFER_SRC_PUBTMP_DEFAULT)) {
		case IPV6_PREFER_SRC_PUBLIC:
			pref |= IPV6_PREFER_SRC_PUBLIC;
			break;
		case IPV6_PREFER_SRC_TMP:
			pref |= IPV6_PREFER_SRC_TMP;
			break;
		case IPV6_PREFER_SRC_PUBTMP_DEFAULT:
			break;
		case 0:
			goto pref_skip_pubtmp;
		default:
			goto e_inval;
		}

		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC|
			      IPV6_PREFER_SRC_TMP);
pref_skip_pubtmp:

		/* check HOME/COA conflicts */
		switch (val & (IPV6_PREFER_SRC_HOME|IPV6_PREFER_SRC_COA)) {
		case IPV6_PREFER_SRC_HOME:
			break;
		case IPV6_PREFER_SRC_COA:
			pref |= IPV6_PREFER_SRC_COA;
		case 0:
			goto pref_skip_coa;
		default:
			goto e_inval;
		}

		prefmask &= ~IPV6_PREFER_SRC_COA;
pref_skip_coa:

		/* check CGA/NONCGA conflicts */
		switch (val & (IPV6_PREFER_SRC_CGA|IPV6_PREFER_SRC_NONCGA)) {
		case IPV6_PREFER_SRC_CGA:
		case IPV6_PREFER_SRC_NONCGA:
		case 0:
			break;
		default:
			goto e_inval;
		}

		np->srcprefs = (np->srcprefs & prefmask) | pref;
		retv = 0;

		break;
	    }
	case IPV6_MINHOPCOUNT:
		if (optlen < sizeof(int))
			goto e_inval;
		if (val < 0 || val > 255)
			goto e_inval;
		np->min_hopcount = val;
		retv = 0;
		break;
	case IPV6_DONTFRAG:
		np->dontfrag = valbool;
		retv = 0;
		break;
	case IPV6_AUTOFLOWLABEL:
		np->autoflowlabel = valbool;
		np->autoflowlabel_set = 1;
		retv = 0;
		break;
	case IPV6_RECVFRAGSIZE:
		np->rxopt.bits.recvfragsize = valbool;
		retv = 0;
		break;
	}

	release_sock(sk);
	if (needs_rtnl)
		rtnl_unlock();

	return retv;

e_inval:
	release_sock(sk);
	if (needs_rtnl)
		rtnl_unlock();
	return -EINVAL;
}