From: Andy Shevchenko andriy.shevchenko@linux.intel.com
[ Upstream commit fbdbbe6d3ee502b3bdeb4f255196bb45003614be ]
Since we have a separate routine for VBUS sense, the interrupt may occur before gadget driver is present. Hence, ->setup() call may oops the kernel:
[ 55.245843] BUG: kernel NULL pointer dereference, address: 00000010 ... [ 55.245843] EIP: pch_udc_isr.cold+0x162/0x33f ... [ 55.245843] <IRQ> [ 55.245843] ? pch_udc_svc_data_out+0x160/0x160
Check if driver is present before calling ->setup().
Fixes: f646cf94520e ("USB device driver of Topcliff PCH") Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Link: https://lore.kernel.org/r/20210323153626.54908-2-andriy.shevchenko@linux.int... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/gadget/udc/pch_udc.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-)
diff --git a/drivers/usb/gadget/udc/pch_udc.c b/drivers/usb/gadget/udc/pch_udc.c index 4006c946d993..7026d4b088db 100644 --- a/drivers/usb/gadget/udc/pch_udc.c +++ b/drivers/usb/gadget/udc/pch_udc.c @@ -2325,6 +2325,21 @@ static void pch_udc_svc_data_out(struct pch_udc_dev *dev, int ep_num) pch_udc_set_dma(dev, DMA_DIR_RX); }
+static int pch_udc_gadget_setup(struct pch_udc_dev *dev) + __must_hold(&dev->lock) +{ + int rc; + + /* In some cases we can get an interrupt before driver gets setup */ + if (!dev->driver) + return -ESHUTDOWN; + + spin_unlock(&dev->lock); + rc = dev->driver->setup(&dev->gadget, &dev->setup_data); + spin_lock(&dev->lock); + return rc; +} + /** * pch_udc_svc_control_in() - Handle Control IN endpoint interrupts * @dev: Reference to the device structure @@ -2396,15 +2411,12 @@ static void pch_udc_svc_control_out(struct pch_udc_dev *dev) dev->gadget.ep0 = &dev->ep[UDC_EP0IN_IDX].ep; else /* OUT */ dev->gadget.ep0 = &ep->ep; - spin_lock(&dev->lock); /* If Mass storage Reset */ if ((dev->setup_data.bRequestType == 0x21) && (dev->setup_data.bRequest == 0xFF)) dev->prot_stall = 0; /* call gadget with setup data received */ - setup_supported = dev->driver->setup(&dev->gadget, - &dev->setup_data); - spin_unlock(&dev->lock); + setup_supported = pch_udc_gadget_setup(dev);
if (dev->setup_data.bRequestType & USB_DIR_IN) { ep->td_data->status = (ep->td_data->status & @@ -2652,9 +2664,7 @@ static void pch_udc_svc_intf_interrupt(struct pch_udc_dev *dev) dev->ep[i].halted = 0; } dev->stall = 0; - spin_unlock(&dev->lock); - dev->driver->setup(&dev->gadget, &dev->setup_data); - spin_lock(&dev->lock); + pch_udc_gadget_setup(dev); }
/** @@ -2689,9 +2699,7 @@ static void pch_udc_svc_cfg_interrupt(struct pch_udc_dev *dev) dev->stall = 0;
/* call gadget zero with setup data received */ - spin_unlock(&dev->lock); - dev->driver->setup(&dev->gadget, &dev->setup_data); - spin_lock(&dev->lock); + pch_udc_gadget_setup(dev); }
/**