03.02.2023 13:45, Greg Kroah-Hartman пишет:
On Fri, Feb 03, 2023 at 01:18:28PM +0300, Anastasia Belova wrote:Before dereferencing dev->driver check it for NULL. If an interrupt handler is called after assigning NULL to dev->driver, but before resetting dev->int_enable, NULL-pointer will be dereferenced. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Anastasia Belova <abelova@xxxxxxxxxxxxx> --- drivers/usb/gadget/udc/goku_udc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/udc/goku_udc.c b/drivers/usb/gadget/udc/goku_udc.c index bdc56b24b5c9..896bba8b47f1 100644 --- a/drivers/usb/gadget/udc/goku_udc.c +++ b/drivers/usb/gadget/udc/goku_udc.c @@ -1616,8 +1616,9 @@ static irqreturn_t goku_irq(int irq, void *_dev) pm_next: if (stat & INT_USBRESET) { /* hub reset done */ ACK(INT_USBRESET); - INFO(dev, "USB reset done, gadget %s\n", - dev->driver->driver.name); + if (dev->driver) + INFO(dev, "USB reset done, gadget %s\n", + dev->driver->driver.name);How can this ever happen? Can you trigger this somehow? If not, I don't think this is going to be possible (also what's up with printk from an irq handler???)
Unfortunately, I can't find the way to trigger this at the moment. What about printk, should trace_printk be used instead?
Odds are, no one actually has this hardware anymore, right?
Despite of this, such vulnerability should be fixed because there is a possibility to exploit it.
thanks, greg k-h
Best regards, Anastasia Belova
