Re: [BUG] usb: serial: garmin_gps: A possible concurrency use-after-free bug

[Jia-Ju Bai]

On 2018/12/20 21:46, Johan Hovold wrote:
> On Thu, Dec 20, 2018 at 09:41:16PM +0800, Jia-Ju Bai wrote:
> > In drivers/usb/serial/garmin_gps.c,
> > the functions garmin_read_bulk_callback() and garmin_write_bulk_callback()
> > may be concurrently executed.
> >
> > In garmin_write_bulk_callback() on line 969:
> >       kfree(urb->transfer_buffer);
> > In garmin_read_bulk_callback() on line 1165:
> >       unsigned char *data = urb->transfer_buffer;
> > Thus, a concurrency use-after-free bug may occur.
> No, they operate on different struct urb.
>
> > This possible bug is found by a static analysis tool written by myself.
> Seems you need to update your tool. Please also make sure to review its
> output before reporting anything.

Okay, thanks for your reply.
Sorry for my false positive...


Best wishes,
Jia-Ju Bai