If anybody comes up with a patch to fix the original issue I easily can test it, since I'm hitting "BUG: Bad page state" in a second when fuzzing with KTSAN and Trinity. On Tue, Sep 15, 2015 at 9:01 PM, Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> wrote: > On Tue, Sep 15, 2015 at 01:36:45PM -0400, Sasha Levin wrote: >> On 09/11/2015 09:27 PM, Hugh Dickins wrote: >> > I'm inclined to echo Vlastimil's comment from earlier in the thread: >> > sounds like an overkill, unless we find something more serious than this. >> >> I've modified my tests to stress the exit path of processes with many vmas, > > Could you share the test? > >> and hit the following NULL ptr deref (not sure if it's related to the original issue): >> >> [1181047.935563] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN >> [1181047.937223] Modules linked in: >> [1181047.937772] CPU: 4 PID: 21912 Comm: trinity-c341 Not tainted 4.3.0-rc1-next-20150914-sasha-00043-geddd763-dirty #2554 >> [1181047.939387] task: ffff8804195c8000 ti: ffff880433f00000 task.ti: ffff880433f00000 >> [1181047.940533] RIP: unmap_vmas (mm/memory.c:1337) > > Is it "struct mm_struct *mm = vma->vm_mm;"? > > -- > Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>