Messages in this thread | | | From | Andrey Konovalov <> | Date | Thu, 1 Mar 2018 18:28:52 +0100 | Subject | Re: [PATCH 1/2] kasan: fix invalid-free test crashing the kernel |
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On Thu, Mar 1, 2018 at 6:15 PM, Andrey Konovalov <andreyknvl@google.com> wrote: > When an invalid-free is triggered by one of the KASAN tests, the object > doesn't actually get freed. This later leads to a BUG failure in > kmem_cache_destroy that checks that there are no allocated objects in the > cache that is being destroyed. Fix this by calling kmem_cache_free with > the proper object address after the call that triggers invalid-free.
Note, that for this patch to fix the issue, it is supposed to go on top of the "kasan, slub: fix handling of kasan_slab_free hook" patch I sent recently.
https://patchwork.kernel.org/patch/10238179/
> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> > --- > lib/test_kasan.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/lib/test_kasan.c b/lib/test_kasan.c > index 98854a64b014..ec657105edbf 100644 > --- a/lib/test_kasan.c > +++ b/lib/test_kasan.c > @@ -567,7 +567,15 @@ static noinline void __init kmem_cache_invalid_free(void) > return; > } > > + /* Trigger invalid free, the object doesn't get freed */ > kmem_cache_free(cache, p + 1); > + > + /* > + * Properly free the object to prevent the "Objects remaining in > + * test_cache on __kmem_cache_shutdown" BUG failure. > + */ > + kmem_cache_free(cache, p); > + > kmem_cache_destroy(cache); > } > > -- > 2.16.2.395.g2e18187dfd-goog >
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