diff --git a/drivers/uio/uio_pci_generic.c b/drivers/uio/uio_pci_generic.c index 8773e373ffe5..dde5cbb27178 100644 --- a/drivers/uio/uio_pci_generic.c +++ b/drivers/uio/uio_pci_generic.c @@ -39,6 +39,22 @@ to_uio_pci_generic_dev(struct uio_info *info) return container_of(info, struct uio_pci_generic_dev, info); } +static int release(struct uio_info *info, struct inode *inode) +{ + struct uio_pci_generic_dev *gdev = to_uio_pci_generic_dev(info); + + /* + * This driver is insecure when used with devices doing DMA, but some +  * people (mis)use it with such devices. +  * Let's at least make sure DMA isn't left enabled after the userspace +  * driver closes the fd. +  * Note that there's a non-zero chance doing this will wedge the device +  * at least until reset. + */ + pci_clear_master(gdev->pdev); + return 0; +} + /* Interrupt handler. Read/modify/write the command register to disable * the interrupt. */ static irqreturn_t irqhandler(int irq, struct uio_info *info) @@ -78,6 +94,7 @@ static int probe(struct pci_dev *pdev, gdev->info.name = "uio_pci_generic"; gdev->info.version = DRIVER_VERSION; + gdev->info.release = release; gdev->pdev = pdev; if (pdev->irq) { gdev->info.irq = pdev->irq;