On Mon, 2020-08-24 at 13:50 +0200, Marco Elver wrote: > On Mon, 24 Aug 2020 at 10:07, 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 queueing stack information. It is useful for > > programmers to solve use-after-free or double-free memory issue. > > > > Generic KASAN will record the last two workqueue and timer stacks, > > print 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 > > > > --- > > > > 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. > > Much cleaner. > > In general, > > Acked-by: Marco Elver <elver@xxxxxxxxxx> > > but I left some more comments. I'm a bit worried about the tests, > because of KASAN-test KUnit rework, but probably not much we can do > until these are added to -mm tree. > Hi Marco, Thanks for your review and friendly reminder. If needed, I will rebase and resend the test case. Walter > Thanks, > -- Marco
