[PATCH AUTOSEL 5.15 085/109] nvme-pci: fix a NULL pointer dereference in nvme_alloc_admin_tags

[PATCH AUTOSEL 5.15 085/109] nvme-pci: fix a NULL pointer dereference in nvme_alloc_admin_tags

[Sasha Levin]

From: "Smith, Kyle Miller (Nimble Kernel)" <kyles@hpe.com>

[ Upstream commit da42761181627e9bdc37d18368b827948a583929 ]

In nvme_alloc_admin_tags, the admin_q can be set to an error (typically
-ENOMEM) if the blk_mq_init_queue call fails to set up the queue, which
is checked immediately after the call. However, when we return the error
message up the stack, to nvme_reset_work the error takes us to
nvme_remove_dead_ctrl()
  nvme_dev_disable()
   nvme_suspend_queue(&dev->queues[0]).

Here, we only check that the admin_q is non-NULL, rather than not
an error or NULL, and begin quiescing a queue that never existed, leading
to bad / NULL pointer dereference.

Signed-off-by: Kyle Smith <kyles@hpe.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/nvme/host/pci.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index e6f55cf6e494..3ddd24a42043 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1680,6 +1680,7 @@ static int nvme_alloc_admin_tags(struct nvme_dev *dev)
 		dev->ctrl.admin_q = blk_mq_init_queue(&dev->admin_tagset);
 		if (IS_ERR(dev->ctrl.admin_q)) {
 			blk_mq_free_tag_set(&dev->admin_tagset);
+			dev->ctrl.admin_q = NULL;
 			return -ENOMEM;
 		}
 		if (!blk_get_queue(dev->ctrl.admin_q)) {
-- 
2.35.1

[PATCH AUTOSEL 5.15 096/109] nvme: set non-mdts limits in nvme_scan_work

[Sasha Levin]

From: Chaitanya Kulkarni <kch@nvidia.com>

[ Upstream commit 78288665b5d0154978fed431985310cb4f166836 ]

In current implementation we set the non-mdts limits by calling
nvme_init_non_mdts_limits() from nvme_init_ctrl_finish().
This also tries to set the limits for the discovery controller which
has no I/O queues resulting in the warning message reported by the
nvme_log_error() when running blktest nvme/002: -

[ 2005.155946] run blktests nvme/002 at 2022-04-09 16:57:47
[ 2005.192223] loop: module loaded
[ 2005.196429] nvmet: adding nsid 1 to subsystem blktests-subsystem-0
[ 2005.200334] nvmet: adding nsid 1 to subsystem blktests-subsystem-1

<------------------------------SNIP---------------------------------->

[ 2008.958108] nvmet: adding nsid 1 to subsystem blktests-subsystem-997
[ 2008.962082] nvmet: adding nsid 1 to subsystem blktests-subsystem-998
[ 2008.966102] nvmet: adding nsid 1 to subsystem blktests-subsystem-999
[ 2008.973132] nvmet: creating discovery controller 1 for subsystem nqn.2014-08.org.nvmexpress.discovery for NQN testhostnqn.
*[ 2008.973196] nvme1: Identify(0x6), Invalid Field in Command (sct 0x0 / sc 0x2) MORE DNR*
[ 2008.974595] nvme nvme1: new ctrl: "nqn.2014-08.org.nvmexpress.discovery"
[ 2009.103248] nvme nvme1: Removing ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery"

Move the call of nvme_init_non_mdts_limits() to nvme_scan_work() after
we verify that I/O queues are created since that is a converging point
for each transport where these limits are actually used.

1. FC :
nvme_fc_create_association()
 ...
 nvme_fc_create_io_queues(ctrl);
 ...
 nvme_start_ctrl()
  nvme_scan_queue()
   nvme_scan_work()

2. PCIe:-
nvme_reset_work()
 ...
 nvme_setup_io_queues()
  nvme_create_io_queues()
   nvme_alloc_queue()
 ...
 nvme_start_ctrl()
  nvme_scan_queue()
   nvme_scan_work()

3. RDMA :-
nvme_rdma_setup_ctrl
 ...
  nvme_rdma_configure_io_queues
  ...
  nvme_start_ctrl()
   nvme_scan_queue()
    nvme_scan_work()

4. TCP :-
nvme_tcp_setup_ctrl
 ...
  nvme_tcp_configure_io_queues
  ...
  nvme_start_ctrl()
   nvme_scan_queue()
    nvme_scan_work()

* nvme_scan_work()
...
nvme_validate_or_alloc_ns()
  nvme_alloc_ns()
   nvme_update_ns_info()
    nvme_update_disk_info()
     nvme_config_discard() <---
     blk_queue_max_write_zeroes_sectors() <---

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/nvme/host/core.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 87877397d1ad..711b89424bd0 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3032,10 +3032,6 @@ int nvme_init_ctrl_finish(struct nvme_ctrl *ctrl)
 	if (ret)
 		return ret;
 
-	ret = nvme_init_non_mdts_limits(ctrl);
-	if (ret < 0)
-		return ret;
-
 	ret = nvme_configure_apst(ctrl);
 	if (ret < 0)
 		return ret;
@@ -4096,11 +4092,26 @@ static void nvme_scan_work(struct work_struct *work)
 {
 	struct nvme_ctrl *ctrl =
 		container_of(work, struct nvme_ctrl, scan_work);
+	int ret;
 
 	/* No tagset on a live ctrl means IO queues could not created */
 	if (ctrl->state != NVME_CTRL_LIVE || !ctrl->tagset)
 		return;
 
+	/*
+	 * Identify controller limits can change at controller reset due to
+	 * new firmware download, even though it is not common we cannot ignore
+	 * such scenario. Controller's non-mdts limits are reported in the unit
+	 * of logical blocks that is dependent on the format of attached
+	 * namespace. Hence re-read the limits at the time of ns allocation.
+	 */
+	ret = nvme_init_non_mdts_limits(ctrl);
+	if (ret < 0) {
+		dev_warn(ctrl->device,
+			"reading non-mdts-limits failed: %d\n", ret);
+		return;
+	}
+
 	if (test_and_clear_bit(NVME_AER_NOTICE_NS_CHANGED, &ctrl->events)) {
 		dev_info(ctrl->device, "rescanning namespaces.\n");
 		nvme_clear_changed_ns_log(ctrl);
-- 
2.35.1