3.16.62-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Parav Pandit parav@mellanox.com
commit 954a8e3aea87e896e320cf648c1a5bbe47de443e upstream.
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.
Fixes: f17df3b0dede ("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 Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/infiniband/core/cma.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)
--- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -434,6 +434,7 @@ static int cma_resolve_ib_dev(struct rdm dgid = (union ib_gid *) &addr->sib_addr; pkey = ntohs(addr->sib_pkey);
+ mutex_lock(&lock); list_for_each_entry(cur_dev, &dev_list, list) { if (rdma_node_get_transport(cur_dev->device->node_type) != RDMA_TRANSPORT_IB) continue; @@ -455,18 +456,19 @@ static int cma_resolve_ib_dev(struct rdm 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; }