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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Kyle Smith <kyles@hpe.com>,
        Chaitanya Kulkarni <kch@nvidia.com>,
        Hannes Reinecke <hare@suse.de>, Christoph Hellwig <hch@lst.de>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 022/167] nvme-pci: fix a NULL pointer dereference in nvme_alloc_admin_tags
Date:   Mon, 13 Jun 2022 12:08:16 +0200
Message-Id: <20220613094846.026729618@linuxfoundation.org>
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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 c87f27d3ee31..e7b872592f36 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1203,6 +1203,7 @@ 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