On Mon, Jun 08, 2020 at 01:48:28PM +0200, Matthias Brugger wrote:
>
>
> On 08/06/2020 12:57, Greg KH wrote:
> > On Mon, Jun 08, 2020 at 11:52:16AM +0200, matthias....@kernel.org wrote:
> >> From: Matthias Brugger <mbrug...@suse.com>
> >>
> >> If we pass a driver without a name, we end up in a NULL pointer
> >> derefernce.
> >
> > That's a very good reason not to have a driver without a name :)
> >
> > What in-kernel driver does this?
> >
> >> Check for the name before trying to register the driver.
> >> As we don't have a driver name to point to in the error message, we dump
> >> the call stack to make it easier to detect the buggy driver.
> >>
> >> Reported-by: kernel test robot <l...@intel.com>
> >> Signed-off-by: Matthias Brugger <mbrug...@suse.com>
> >> ---
> >> drivers/base/driver.c | 6 ++++++
> >> 1 file changed, 6 insertions(+)
> >>
> >> diff --git a/drivers/base/driver.c b/drivers/base/driver.c
> >> index 57c68769e157..40fba959c140 100644
> >> --- a/drivers/base/driver.c
> >> +++ b/drivers/base/driver.c
> >> @@ -149,6 +149,12 @@ int driver_register(struct device_driver *drv)
> >> int ret;
> >> struct device_driver *other;
> >>
> >> + if (!drv->name) {
> >> + pr_err("Driver has no name.\n");
> >> + dump_stack();
> >> + return -EINVAL;
> >
> > Ick, no, an oops-traceback for doing something dumb like this should be
> > all that we need, right?
> >
> > How "hardened" do we need to make internal apis anyway? What's the odds
> > that if this does trigger, the driver author would even notice it?
> >
>
> We just had the case that a driver got accepted in a maintainer repository
> without a name. Which got later found by the kernel test robot.
That driver had obviously never actually been run before :(
> I agree with you that it probably doesn't make much sense to check for this
> kind
> of bugs, as it should be discoverable if you test your code, before you
> submit.
>
> I propose to ignore this patch.
Thanks, now dropped!
greg k-h
