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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     "Smith, Kyle Miller (Nimble Kernel)" <kyles@hpe.com>,
        Chaitanya Kulkarni <kch@nvidia.com>,
        Hannes Reinecke <hare@suse.de>, Christoph Hellwig <hch@lst.de>,
        Sasha Levin <sashal@kernel.org>, kbusch@kernel.org,
        axboe@fb.com, sagi@grimberg.me, linux-nvme@lists.infradead.org
Subject: [PATCH AUTOSEL 5.4 45/55] nvme-pci: fix a NULL pointer dereference in nvme_alloc_admin_tags
Date:   Mon, 30 May 2022 09:46:51 -0400
Message-Id: <20220530134701.1935933-45-sashal@kernel.org>
In-Reply-To: <20220530134701.1935933-1-sashal@kernel.org>
References: <20220530134701.1935933-1-sashal@kernel.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 af516c35afe6..10fe7a7a2163 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1674,6 +1674,7 @@ 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