RDMA/cma: Protect cma dev list with lock

When AF_IB addresses are used during rdma_resolve_addr() a lock is not
held. A cma device can get removed while list traversal is in progress
which may lead to crash. ie

        CPU0                                     CPU1
        ====                                     ====
rdma_resolve_addr()
 cma_resolve_ib_dev()
  list_for_each()                         cma_remove_one()
    cur_dev->device                        mutex_lock(&lock)
                                            list_del();
                                           mutex_unlock(&lock);
                                           cma_process_remove();


Therefore, hold a lock while traversing the list which avoids such
situation.

Cc: <stable@vger.kernel.org> # 3.10
Fixes: f17df3b0de ("RDMA/cma: Add support for AF_IB to rdma_resolve_addr()")
Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Parav Pandit 2018-08-30 08:35:19 +03:00 committed by Jason Gunthorpe
parent 08e74be103
commit 954a8e3aea

View File

@ -724,6 +724,7 @@ static int cma_resolve_ib_dev(struct rdma_id_private *id_priv)
dgid = (union ib_gid *) &addr->sib_addr;
pkey = ntohs(addr->sib_pkey);
mutex_lock(&lock);
list_for_each_entry(cur_dev, &dev_list, list) {
for (p = 1; p <= cur_dev->device->phys_port_cnt; ++p) {
if (!rdma_cap_af_ib(cur_dev->device, p))
@ -750,18 +751,19 @@ static int cma_resolve_ib_dev(struct rdma_id_private *id_priv)
cma_dev = cur_dev;
sgid = gid;
id_priv->id.port_num = p;
goto found;
}
}
}
}
if (!cma_dev)
return -ENODEV;
mutex_unlock(&lock);
return -ENODEV;
found:
cma_attach_to_dev(id_priv, cma_dev);
addr = (struct sockaddr_ib *) cma_src_addr(id_priv);
memcpy(&addr->sib_addr, &sgid, sizeof sgid);
mutex_unlock(&lock);
addr = (struct sockaddr_ib *)cma_src_addr(id_priv);
memcpy(&addr->sib_addr, &sgid, sizeof(sgid));
cma_translate_ib(addr, &id_priv->id.route.addr.dev_addr);
return 0;
}