On Monday, March 28, 2016 11:18:05 AM Darren Hart wrote: > On Mon, Mar 28, 2016 at 05:18:39PM +0100, Colin King wrote: > > From: Colin Ian King <colin.king@xxxxxxxxxxxxx> > > > > intel_menlow_memory_remove sanity checks to see if device is null, however, > > this check is performed after we have already passed device into a call > > to acpi_driver_data. If device is null, then acpi_driver_data will produce > > a null pointer dereference on device. The correct action is to sanity check > > device, then assign cdev, then check if cdev is null. > > > > Hrm, looking at this locally, that all makes sense. > > Taking a step back however, I notice that intel_menlow_memory_remove is an ops > function pointer inside the acpi_driver structure itself, which is called from > acpi_device_remove() (and probe) (drivers/acpi/bus.c). This already verifies > acpi_driver is not NULL and can't get acpi_driver if acpi_device is NULL. So > unless there is some other use case for this callback I'm unaware of (certainly > possible) it appears to be totally redundant to do this checking here. > > +Rafael - is there a best practices for these acpi callbacks with respect to > input validation? No best practices I'm aware of, but if the core does this checks anyway before calling this, they are clearly not necessary here. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe platform-driver-x86" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
