From fa14a0acea1ffe67913ba384a2897130a36dfe03 Mon Sep 17 00:00:00 2001 From: Bart Van Assche <bart.vanassche@sandisk.com> Date: Tue, 1 Nov 2016 18:36:46 +0200 Subject: [PATCH] nvmet-rdma: Fix possible NULL deref when handling rdma cm events When we initiate queue teardown sequence we call rdma_destroy_qp which clears cm_id->qp, afterwards we call rdma_destroy_id, but we might see a rdma_cm event in between with a cleared cm_id->qp so watch out for that and silently ignore the event because this means that the queue teardown sequence is in progress. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> --- drivers/nvme/target/rdma.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c index f8d23999e0f2..cf60759cc169 100644 --- a/drivers/nvme/target/rdma.c +++ b/drivers/nvme/target/rdma.c @@ -1352,7 +1352,13 @@ static int nvmet_rdma_cm_handler(struct rdma_cm_id *cm_id, case RDMA_CM_EVENT_ADDR_CHANGE: case RDMA_CM_EVENT_DISCONNECTED: case RDMA_CM_EVENT_TIMEWAIT_EXIT: - nvmet_rdma_queue_disconnect(queue); + /* + * We might end up here when we already freed the qp + * which means queue release sequence is in progress, + * so don't get in the way... + */ + if (queue) + nvmet_rdma_queue_disconnect(queue); break; case RDMA_CM_EVENT_DEVICE_REMOVAL: ret = nvmet_rdma_device_removal(cm_id, queue);