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> > --- > > Changes since v2: > - modify kasan document to be more readable. > Thanks for Marco suggestion. > > Changes since v1: > - Thanks for Marco and Thomas suggestion. > - Remove unnecessary code and fix commit log > - reuse kasan_record_aux_stack() and aux_stack > to record timer and workqueue stack. > - change the aux stack title for common name. > > --- > > Documentation/dev-tools/kasan.rst | 4 ++-- > kernel/time/timer.c | 3 +++ > kernel/workqueue.c | 3 +++ > lib/test_kasan.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ > mm/kasan/report.c | 4 ++-- > 5 files changed, 64 insertions(+), 4 deletions(-) > > -- > You received this message because you are subscribed to the Google Groups "kasan-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/20200825015654.27781-1-walter-zh.wu%40mediatek.com.
