Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Omar Sandoval , Jeff Moyer , Jens Axboe , Sasha Levin Subject: [PATCH 4.4 51/58] virtio_blk: fix panic in initialization error path Date: Wed, 9 Aug 2017 12:42:03 -0700 Message-Id: <20170809194148.495615426@linuxfoundation.org> In-Reply-To: <20170809194146.501519882@linuxfoundation.org> References: <20170809194146.501519882@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Omar Sandoval [ Upstream commit 6bf6b0aa3da84a3d9126919a94c49c0fb7ee2fb3 ] If blk_mq_init_queue() returns an error, it gets assigned to vblk->disk->queue. Then, when we call put_disk(), we end up calling blk_put_queue() with the ERR_PTR, causing a bad dereference. Fix it by only assigning to vblk->disk->queue on success. Signed-off-by: Omar Sandoval Reviewed-by: Jeff Moyer Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/block/virtio_blk.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -641,11 +641,12 @@ static int virtblk_probe(struct virtio_d if (err) goto out_put_disk; - q = vblk->disk->queue = blk_mq_init_queue(&vblk->tag_set); + q = blk_mq_init_queue(&vblk->tag_set); if (IS_ERR(q)) { err = -ENOMEM; goto out_free_tags; } + vblk->disk->queue = q; q->queuedata = vblk;