From 97cee53a94be3bd4fd8fbed6071bd2f32dad1ab1 Mon Sep 17 00:00:00 2001 From: Ruoyu Wang Date: Wed, 10 Jun 2026 20:10:22 +0800 Subject: [PATCH] usb: gadget: aspeed_udc: check endpoint DMA allocation ast_udc_probe() allocates a coherent DMA buffer used as the backing store for endpoint buffers. ast_udc_init_ep() derives per-endpoint buffer pointers from udc->ep0_buf, so a failed allocation is dereferenced during probe. Check the allocation before endpoint setup. The existing probe error path called ast_udc_remove(), which unregisters the gadget unconditionally and is not safe before usb_add_gadget_udc() succeeds. Add a local cleanup helper for probe failures so pre-registration failures only unwind the resources that were actually initialized. This was found by a local static analysis checker for unchecked allocator returns while scanning Linux 6.16. The change was checked by applying it to current mainline and by running checkpatch. I do not have access to Aspeed UDC hardware, so no runtime testing was performed. Fixes: 055276c13205 ("usb: gadget: add Aspeed ast2600 udc driver") Signed-off-by: Ruoyu Wang Reviewed-by: Andrew Jeffery Link: https://patch.msgid.link/20260610121022.3-1-ruoyuw560@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/udc/aspeed_udc.c | 50 ++++++++++++++++++----------- 1 file changed, 32 insertions(+), 18 deletions(-) diff --git a/drivers/usb/gadget/udc/aspeed_udc.c b/drivers/usb/gadget/udc/aspeed_udc.c index 75f9c831b21a..54f81e668009 100644 --- a/drivers/usb/gadget/udc/aspeed_udc.c +++ b/drivers/usb/gadget/udc/aspeed_udc.c @@ -1431,25 +1431,12 @@ static void ast_udc_init_hw(struct ast_udc_dev *udc) ast_udc_write(udc, 0, AST_UDC_EP0_CTRL); } -static void ast_udc_remove(struct platform_device *pdev) +static void ast_udc_cleanup(struct platform_device *pdev) { struct ast_udc_dev *udc = platform_get_drvdata(pdev); unsigned long flags; u32 ctrl; - usb_del_gadget_udc(&udc->gadget); - if (udc->driver) { - /* - * This is broken as only some cleanup is skipped, *udev is - * freed and the register mapping goes away. Any further usage - * probably crashes. Also the device is unbound, so the skipped - * cleanup is never catched up later. - */ - dev_alert(&pdev->dev, - "Driver is busy and still going away. Fasten your seat belts!\n"); - return; - } - spin_lock_irqsave(&udc->lock, flags); /* Disable upstream port connection */ @@ -1469,6 +1456,26 @@ static void ast_udc_remove(struct platform_device *pdev) udc->ep0_buf = NULL; } +static void ast_udc_remove(struct platform_device *pdev) +{ + struct ast_udc_dev *udc = platform_get_drvdata(pdev); + + usb_del_gadget_udc(&udc->gadget); + if (udc->driver) { + /* + * This is broken as only some cleanup is skipped, *udev is + * freed and the register mapping goes away. Any further usage + * probably crashes. Also the device is unbound, so the skipped + * cleanup is never catched up later. + */ + dev_alert(&pdev->dev, + "Driver is busy and still going away. Fasten your seat belts!\n"); + return; + } + + ast_udc_cleanup(pdev); +} + static int ast_udc_probe(struct platform_device *pdev) { enum usb_device_speed max_speed; @@ -1521,6 +1528,12 @@ static int ast_udc_probe(struct platform_device *pdev) AST_UDC_NUM_ENDPOINTS, &udc->ep0_buf_dma, GFP_KERNEL); + if (!udc->ep0_buf) { + clk_disable_unprepare(udc->clk); + rc = -ENOMEM; + goto err; + } + udc->gadget.speed = USB_SPEED_UNKNOWN; udc->gadget.max_speed = USB_SPEED_HIGH; udc->creq = udc->reg + AST_UDC_SETUP0; @@ -1550,20 +1563,20 @@ static int ast_udc_probe(struct platform_device *pdev) udc->irq = platform_get_irq(pdev, 0); if (udc->irq < 0) { rc = udc->irq; - goto err; + goto err_cleanup; } rc = devm_request_irq(&pdev->dev, udc->irq, ast_udc_isr, 0, KBUILD_MODNAME, udc); if (rc) { dev_err(&pdev->dev, "Failed to request interrupt\n"); - goto err; + goto err_cleanup; } rc = usb_add_gadget_udc(&pdev->dev, &udc->gadget); if (rc) { dev_err(&pdev->dev, "Failed to add gadget udc\n"); - goto err; + goto err_cleanup; } dev_info(&pdev->dev, "Initialized udc in USB%s mode\n", @@ -1571,9 +1584,10 @@ static int ast_udc_probe(struct platform_device *pdev) return 0; +err_cleanup: + ast_udc_cleanup(pdev); err: dev_err(&pdev->dev, "Failed to udc probe, rc:0x%x\n", rc); - ast_udc_remove(pdev); return rc; }