Commit 33fb27fd authored by Bernard Metzler's avatar Bernard Metzler Committed by Jason Gunthorpe
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RDMA/siw: Fix passive connection establishment 

Holding the rtnl_lock while iterating a devices interface address list
potentially causes deadlocks with the cma_netdev_callback. While this was
implemented to limit the scope of a wildcard listen to addresses of the
current device only, a better solution limits the scope of the socket to
the device. This completely avoiding locking, and also results in
significant code simplification.

Fixes: c421651f ("RDMA/siw: Add missing rtnl_lock around access to ifa")
Link: https://lore.kernel.org/r/20200228173534.26815-1-bmt@zurich.ibm.com


Reported-by: default avatar <syzbot+55de90ab5f44172b0c90@syzkaller.appspotmail.com>
Suggested-by: default avatarJason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: default avatarBernard Metzler <bmt@zurich.ibm.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 79db784e

drivers/infiniband/sw/siw/siw_cm.c

+31 −106
Original line number Diff line number Diff line
@@ -1769,14 +1769,23 @@ int siw_reject(struct iw_cm_id *id, const void *pdata, u8 pd_len) 
	return 0;

}



static int siw_listen_address(struct iw_cm_id *id, int backlog,

			      struct sockaddr *laddr, int addr_family)

/*

 * siw_create_listen - Create resources for a listener's IWCM ID @id

 *

 * Starts listen on the socket address id->local_addr.

 *

 */

int siw_create_listen(struct iw_cm_id *id, int backlog)

{

	struct socket *s;

	struct siw_cep *cep = NULL;

	struct siw_device *sdev = to_siw_dev(id->device);

	int addr_family = id->local_addr.ss_family;

	int rv = 0, s_val;



	if (addr_family != AF_INET && addr_family != AF_INET6)

		return -EAFNOSUPPORT;



	rv = sock_create(addr_family, SOCK_STREAM, IPPROTO_TCP, &s);

	if (rv < 0)

		return rv;
@@ -1791,9 +1800,25 @@ static int siw_listen_address(struct iw_cm_id *id, int backlog, 
		siw_dbg(id->device, "setsockopt error: %d\n", rv);

		goto error;

	}

	rv = s->ops->bind(s, laddr, addr_family == AF_INET ?

				    sizeof(struct sockaddr_in) :

	if (addr_family == AF_INET) {

		struct sockaddr_in *laddr = &to_sockaddr_in(id->local_addr);



		/* For wildcard addr, limit binding to current device only */

		if (ipv4_is_zeronet(laddr->sin_addr.s_addr))

			s->sk->sk_bound_dev_if = sdev->netdev->ifindex;



		rv = s->ops->bind(s, (struct sockaddr *)laddr,

				  sizeof(struct sockaddr_in));

	} else {

		struct sockaddr_in6 *laddr = &to_sockaddr_in6(id->local_addr);



		/* For wildcard addr, limit binding to current device only */

		if (ipv6_addr_any(&laddr->sin6_addr))

			s->sk->sk_bound_dev_if = sdev->netdev->ifindex;



		rv = s->ops->bind(s, (struct sockaddr *)laddr,

				  sizeof(struct sockaddr_in6));

	}

	if (rv) {

		siw_dbg(id->device, "socket bind error: %d\n", rv);

		goto error;
@@ -1852,7 +1877,7 @@ static int siw_listen_address(struct iw_cm_id *id, int backlog, 
	list_add_tail(&cep->listenq, (struct list_head *)id->provider_data);

	cep->state = SIW_EPSTATE_LISTENING;



	siw_dbg(id->device, "Listen at laddr %pISp\n", laddr);

	siw_dbg(id->device, "Listen at laddr %pISp\n", &id->local_addr);



	return 0;
@@ -1910,106 +1935,6 @@ static void siw_drop_listeners(struct iw_cm_id *id) 
	}

}



/*

 * siw_create_listen - Create resources for a listener's IWCM ID @id

 *

 * Listens on the socket address id->local_addr.

 *

 * If the listener's @id provides a specific local IP address, at most one

 * listening socket is created and associated with @id.

 *

 * If the listener's @id provides the wildcard (zero) local IP address,

 * a separate listen is performed for each local IP address of the device

 * by creating a listening socket and binding to that local IP address.

 *

 */

int siw_create_listen(struct iw_cm_id *id, int backlog)

{

	struct net_device *dev = to_siw_dev(id->device)->netdev;

	int rv = 0, listeners = 0;



	siw_dbg(id->device, "backlog %d\n", backlog);



	/*

	 * For each attached address of the interface, create a

	 * listening socket, if id->local_addr is the wildcard

	 * IP address or matches the IP address.

	 */

	if (id->local_addr.ss_family == AF_INET) {

		struct in_device *in_dev = in_dev_get(dev);

		struct sockaddr_in s_laddr;

		const struct in_ifaddr *ifa;



		if (!in_dev) {

			rv = -ENODEV;

			goto out;

		}

		memcpy(&s_laddr, &id->local_addr, sizeof(s_laddr));



		siw_dbg(id->device, "laddr %pISp\n", &s_laddr);



		rtnl_lock();

		in_dev_for_each_ifa_rtnl(ifa, in_dev) {

			if (ipv4_is_zeronet(s_laddr.sin_addr.s_addr) ||

			    s_laddr.sin_addr.s_addr == ifa->ifa_address) {

				s_laddr.sin_addr.s_addr = ifa->ifa_address;



				rv = siw_listen_address(id, backlog,

						(struct sockaddr *)&s_laddr,

						AF_INET);

				if (!rv)

					listeners++;

			}

		}

		rtnl_unlock();

		in_dev_put(in_dev);

	} else if (id->local_addr.ss_family == AF_INET6) {

		struct inet6_dev *in6_dev = in6_dev_get(dev);

		struct inet6_ifaddr *ifp;

		struct sockaddr_in6 *s_laddr = &to_sockaddr_in6(id->local_addr);



		if (!in6_dev) {

			rv = -ENODEV;

			goto out;

		}

		siw_dbg(id->device, "laddr %pISp\n", &s_laddr);



		rtnl_lock();

		list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {

			if (ifp->flags & (IFA_F_TENTATIVE | IFA_F_DEPRECATED))

				continue;

			if (ipv6_addr_any(&s_laddr->sin6_addr) ||

			    ipv6_addr_equal(&s_laddr->sin6_addr, &ifp->addr)) {

				struct sockaddr_in6 bind_addr  = {

					.sin6_family = AF_INET6,

					.sin6_port = s_laddr->sin6_port,

					.sin6_flowinfo = 0,

					.sin6_addr = ifp->addr,

					.sin6_scope_id = dev->ifindex };



				rv = siw_listen_address(id, backlog,

						(struct sockaddr *)&bind_addr,

						AF_INET6);

				if (!rv)

					listeners++;

			}

		}

		rtnl_unlock();

		in6_dev_put(in6_dev);

	} else {

		rv = -EAFNOSUPPORT;

	}

out:

	if (listeners)

		rv = 0;

	else if (!rv)

		rv = -EINVAL;



	siw_dbg(id->device, "%s\n", rv ? "FAIL" : "OK");



	return rv;

}



int siw_destroy_listen(struct iw_cm_id *id)

{

	if (!id->provider_data) {

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