On Sun, Sep 13, 2020 at 12:17 PM Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
On Wed, Aug 26, 2020 at 2:30 PM 'Andrey Konovalov' via kasan-dev
<kasan-dev@xxxxxxxxxxxxxxxx> wrote:
>
> On Tue, Aug 25, 2020 at 10:26 AM 'Marco Elver' via kasan-dev
> <kasan-dev@xxxxxxxxxxxxxxxx> wrote:
> >
> > On Tue, 25 Aug 2020 at 03:57, Walter Wu <walter-zh.wu@xxxxxxxxxxxx> wrote:
> > >
> > > Syzbot reports many UAF issues for workqueue or timer, see [1] and [2].
> > > In some of these access/allocation happened in process_one_work(),
> > > we see the free stack is useless in KASAN report, it doesn't help
> > > programmers to solve UAF on workqueue. The same may stand for times.
> > >
> > > This patchset improves KASAN reports by making them to have workqueue
> > > queueing stack and timer stack information. It is useful for programmers
> > > to solve use-after-free or double-free memory issue.
> > >
> > > Generic KASAN also records the last two workqueue and timer stacks and
> > > prints them in KASAN report. It is only suitable for generic KASAN.
> > >
> > > [1]https://groups.google.com/g/syzkaller-bugs/search?q=%22use-after-free%22+process_one_work
> > > [2]https://groups.google.com/g/syzkaller-bugs/search?q=%22use-after-free%22%20expire_timers
> > > [3]https://bugzilla.kernel.org/show_bug.cgi?id=198437
> > >
> > > Walter Wu (6):
> > > timer: kasan: record timer stack
> > > workqueue: kasan: record workqueue stack
> > > kasan: print timer and workqueue stack
> > > lib/test_kasan.c: add timer test case
> > > lib/test_kasan.c: add workqueue test case
> > > kasan: update documentation for generic kasan
> >
> > Acked-by: Marco Elver <elver@xxxxxxxxxx>
>
> Reviewed-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Reviewed-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Thanks! The UAF reports with RCU stacks that I see now are just 🔥🔥🔥
Hi Walter,
This patchset needs to be rebased onto the KASAN-KUNIT patches, which just recently went into the mm tree.
Thanks!
