[PATCH AUTOSEL 5.6 094/149] RDMA/siw: Fix passive connection establishment

Sasha Levin
2020-04-11T23:05:50Z

From: Bernard Metzler <bmt@zurich.ibm.com>

[ Upstream commit 33fb27fd54465c74cbffba6315b2f043e90cec4c ]

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: c421651fa229 ("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: syzbot+55de90ab5f44172b0c90@syzkaller.appspotmail.com
Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/sw/siw/siw_cm.c | 137 +++++++----------------------
1 file changed, 31 insertions(+), 106 deletions(-)

diff --git a/drivers/infiniband/sw/siw/siw_cm.c b/drivers/infiniband/sw/siw/siw_cm.c
index c5651a96b1964..559e5fd3bad8b 100644
--- a/drivers/infiniband/sw/siw/siw_cm.c
+++ b/drivers/infiniband/sw/siw/siw_cm.c
@@ -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) :
- sizeof(struct sockaddr_in6));
+ 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) {
--
2.20.1