This is a note to let you know that I've just added the patch titled nvme-fc: fix double-free scenarios on hw queues to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nvme-fc-fix-double-free-scenarios-on-hw-queues.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 6c1fa6e67d1b484cc511616b3f65255d5bdf49f2 Author: James Smart <jsmart2021@xxxxxxxxx> Date: Thu Nov 21 09:59:37 2019 -0800 nvme-fc: fix double-free scenarios on hw queues [ Upstream commit c869e494ef8b5846d9ba91f1e922c23cd444f0c1 ] If an error occurs on one of the ios used for creating an association, the creating routine has error paths that are invoked by the command failure and the error paths will free up the controller resources created to that point. But... the io was ultimately determined by an asynchronous completion routine that detected the error and which unconditionally invokes the error_recovery path which calls delete_association. Delete association deletes all outstanding io then tears down the controller resources. So the create_association thread can be running in parallel with the error_recovery thread. What was seen was the LLDD received a call to delete a queue, causing the LLDD to do a free of a resource, then the transport called the delete queue again causing the driver to repeat the free call. The second free routine corrupted the allocator. The transport shouldn't be making the duplicate call, and the delete queue is just one of the resources being freed. To fix, it is realized that the create_association path is completely serialized with one command at a time. So the failed io completion will always be seen by the create_association path and as of the failure, there are no ios to terminate and there is no reason to be manipulating queue freeze states, etc. The serialized condition stays true until the controller is transitioned to the LIVE state. Thus the fix is to change the error recovery path to check the controller state and only invoke the teardown path if not already in the CONNECTING state. Reviewed-by: Himanshu Madhani <hmadhani@xxxxxxxxxxx> Reviewed-by: Ewan D. Milne <emilne@xxxxxxxxxx> Signed-off-by: James Smart <jsmart2021@xxxxxxxxx> Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c index d567035571bf..1875f6b8a907 100644 --- a/drivers/nvme/host/fc.c +++ b/drivers/nvme/host/fc.c @@ -2894,10 +2894,22 @@ nvme_fc_reconnect_or_delete(struct nvme_fc_ctrl *ctrl, int status) static void __nvme_fc_terminate_io(struct nvme_fc_ctrl *ctrl) { - nvme_stop_keep_alive(&ctrl->ctrl); + /* + * if state is connecting - the error occurred as part of a + * reconnect attempt. The create_association error paths will + * clean up any outstanding io. + * + * if it's a different state - ensure all pending io is + * terminated. Given this can delay while waiting for the + * aborted io to return, we recheck adapter state below + * before changing state. + */ + if (ctrl->ctrl.state != NVME_CTRL_CONNECTING) { + nvme_stop_keep_alive(&ctrl->ctrl); - /* will block will waiting for io to terminate */ - nvme_fc_delete_association(ctrl); + /* will block will waiting for io to terminate */ + nvme_fc_delete_association(ctrl); + } if (ctrl->ctrl.state != NVME_CTRL_CONNECTING && !nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING))