From 8c705dea5e59509b55b46b5a833e1ed030485668 Mon Sep 17 00:00:00 2001 From: Parav Pandit Date: Thu, 30 Aug 2018 08:35:19 +0300 Subject: [PATCH] RDMA/cma: Protect cma dev list with lock 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. Cc: # 3.10 Fixes: f17df3b0dede ("RDMA/cma: Add support for AF_IB to rdma_resolve_addr()") Signed-off-by: Parav Pandit Reviewed-by: Daniel Jurgens Signed-off-by: Leon Romanovsky Reviewed-by: Dennis Dalessandro Signed-off-by: Jason Gunthorpe Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/core/cma.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index 752dbc3..7c5eca3 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -730,6 +730,7 @@ 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)) @@ -756,18 +757,19 @@ 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; } -- 2.7.4