On Thu 2019-05-02 17:21:08, Greg Kroah-Hartman wrote:
[ Upstream commit fa3a419d2f674b431d38748cb58fb7da17ee8949 ]
The call to of_parse_phandle returns a node pointer with refcount incremented thus it must be explicitly decremented after the last usage.
Detected by coccinelle with the following warnings: ./drivers/net/ethernet/xilinx/xilinx_axienet_main.c:1624:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 1569, but without a corresponding object release within this function.
Signed-off-by: Wen Yang wen.yang99@zte.com.cn Cc: Anirudha Sarangi anirudh@xilinx.com Cc: John Linn John.Linn@xilinx.com Cc: "David S. Miller" davem@davemloft.net Cc: Michal Simek michal.simek@xilinx.com Cc: netdev@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin (Microsoft) sashal@kernel.org
Bug is real, but fix is horrible. This already uses gotos for error handling, so use them....
This fixes it up.
Plus... I do not think these "of_node_put" fixes belong in stable. They are theoretical bugs; so we hold reference to device tree structure. a) it is small, b) it stays in memory, anyway. This does not fix any real problem.
Pavel
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c index 4041c75..490d440 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -1575,15 +1575,13 @@ static int axienet_probe(struct platform_device *pdev) ret = of_address_to_resource(np, 0, &dmares); if (ret) { dev_err(&pdev->dev, "unable to get DMA resource\n"); - of_node_put(np); - goto free_netdev; + goto free_netdev_put; } lp->dma_regs = devm_ioremap_resource(&pdev->dev, &dmares); if (IS_ERR(lp->dma_regs)) { dev_err(&pdev->dev, "could not map DMA regs\n"); ret = PTR_ERR(lp->dma_regs); - of_node_put(np); - goto free_netdev; + goto free_netdev_put; } lp->rx_irq = irq_of_parse_and_map(np, 1); lp->tx_irq = irq_of_parse_and_map(np, 0); @@ -1620,6 +1618,8 @@ static int axienet_probe(struct platform_device *pdev)
return 0;
+free_netdev_put: + of_node_put(np); free_netdev: free_netdev(ndev);
drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c index f24f48f33802..7cfd7ff38e86 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -1574,12 +1574,14 @@ static int axienet_probe(struct platform_device *pdev) ret = of_address_to_resource(np, 0, &dmares); if (ret) { dev_err(&pdev->dev, "unable to get DMA resource\n");
of_node_put(np);of_node_put(np);