From 64f5e9cdd711b030b05062c17b2ecfbce890cf4c Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Wed, 20 May 2020 12:48:12 -0700 Subject: [PATCH] nvmet: fix memory leak when removing namespaces and controllers concurrently When removing a namespace, we add an NS_CHANGE async event, however if the controller admin queue is removed after the event was added but not yet processed, we won't free the aens, resulting in the below memory leak [1]. Fix that by moving nvmet_async_event_free to the final controller release after it is detached from subsys->ctrls ensuring no async events are added, and modify it to simply remove all pending aens. -- $ cat /sys/kernel/debug/kmemleak unreferenced object 0xffff888c1af2c000 (size 32): comm "nvmetcli", pid 5164, jiffies 4295220864 (age 6829.924s) hex dump (first 32 bytes): 28 01 82 3b 8b 88 ff ff 28 01 82 3b 8b 88 ff ff (..;....(..;.... 02 00 04 65 76 65 6e 74 5f 66 69 6c 65 00 00 00 ...event_file... backtrace: [<00000000217ae580>] nvmet_add_async_event+0x57/0x290 [nvmet] [<0000000012aa2ea9>] nvmet_ns_changed+0x206/0x300 [nvmet] [<00000000bb3fd52e>] nvmet_ns_disable+0x367/0x4f0 [nvmet] [<00000000e91ca9ec>] nvmet_ns_free+0x15/0x180 [nvmet] [<00000000a15deb52>] config_item_release+0xf1/0x1c0 [<000000007e148432>] configfs_rmdir+0x555/0x7c0 [<00000000f4506ea6>] vfs_rmdir+0x142/0x3c0 [<0000000000acaaf0>] do_rmdir+0x2b2/0x340 [<0000000034d1aa52>] do_syscall_64+0xa5/0x4d0 [<00000000211f13bc>] entry_SYSCALL_64_after_hwframe+0x6a/0xdf Fixes: a07b4970f464 ("nvmet: add a generic NVMe target") Reported-by: David Milburn Signed-off-by: Sagi Grimberg Tested-by: David Milburn Signed-off-by: Christoph Hellwig --- drivers/nvme/target/core.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c index edf54d99..48f5123 100644 --- a/drivers/nvme/target/core.c +++ b/drivers/nvme/target/core.c @@ -158,14 +158,12 @@ static void nvmet_async_events_process(struct nvmet_ctrl *ctrl, u16 status) static void nvmet_async_events_free(struct nvmet_ctrl *ctrl) { - struct nvmet_req *req; + struct nvmet_async_event *aen, *tmp; mutex_lock(&ctrl->lock); - while (ctrl->nr_async_event_cmds) { - req = ctrl->async_event_cmds[--ctrl->nr_async_event_cmds]; - mutex_unlock(&ctrl->lock); - nvmet_req_complete(req, NVME_SC_INTERNAL | NVME_SC_DNR); - mutex_lock(&ctrl->lock); + list_for_each_entry_safe(aen, tmp, &ctrl->async_events, entry) { + list_del(&aen->entry); + kfree(aen); } mutex_unlock(&ctrl->lock); } @@ -791,10 +789,8 @@ void nvmet_sq_destroy(struct nvmet_sq *sq) * If this is the admin queue, complete all AERs so that our * queue doesn't have outstanding requests on it. */ - if (ctrl && ctrl->sqs && ctrl->sqs[0] == sq) { + if (ctrl && ctrl->sqs && ctrl->sqs[0] == sq) nvmet_async_events_process(ctrl, status); - nvmet_async_events_free(ctrl); - } percpu_ref_kill_and_confirm(&sq->ref, nvmet_confirm_sq); wait_for_completion(&sq->confirm_done); wait_for_completion(&sq->free_done); @@ -1427,6 +1423,7 @@ static void nvmet_ctrl_free(struct kref *ref) ida_simple_remove(&cntlid_ida, ctrl->cntlid); + nvmet_async_events_free(ctrl); kfree(ctrl->sqs); kfree(ctrl->cqs); kfree(ctrl->changed_ns_list); -- 2.7.4