crypto: hisilicon/qm - Fix device reference leak in qm_get_qos_value

commit 59b0afd upstream.

The qm_get_qos_value() function calls bus_find_device_by_name() which
increases the device reference count, but fails to call put_device()
to balance the reference count and lead to a device reference leak.

Add put_device() calls in both the error path and success path to
properly balance the reference count.

Found via static analysis.

Fixes: 22d7a6c ("crypto: hisilicon/qm - add pci bdf number check")
Cc: stable@vger.kernel.org
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Longfang Liu <liulongfang@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Yuuoniy

drivers/crypto/hisilicon/qm.c

@@ -3857,10 +3857,12 @@ static ssize_t qm_get_qos_value(struct hisi_qm *qm, const char *buf,
 	pdev = container_of(dev, struct pci_dev, dev);
 	if (pci_physfn(pdev) != qm->pdev) {
 		pci_err(qm->pdev, "the pdev input does not match the pf!\n");
+		put_device(dev);
 		return -EINVAL;
 	}
 
 	*fun_index = pdev->devfn;
+	put_device(dev);
 
 	return 0;
 }