Messages in this thread | | | From | Daniel Latypov <> | Date | Thu, 9 Sep 2021 10:15:31 -0700 | Subject | Re: [PATCH v2] kunit: fix reference count leak in kfree_at_end |
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On Thu, Sep 9, 2021 at 9:59 AM Daniel Latypov <dlatypov@google.com> wrote: > > On Thu, Sep 9, 2021 at 12:26 AM 'Xiyu Yang' via KUnit Development > <kunit-dev@googlegroups.com> wrote: > > > > The reference counting issue happens in the normal path of > > kfree_at_end(). When kunit_alloc_and_get_resource() is invoked, the > > function forgets to handle the returned resource object, whose refcount > > increased inside, causing a refcount leak. > > > > Fix this issue by calling kunit_alloc_resource() instead of > > kunit_alloc_and_get_resource(). > > > > Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> > > Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> > > Reviewed-by: Daniel Latypov <dlatypov@google.com> > > Ah, thanks for finding and fixing this! > We really should have better documentation/otherwise make it clearer > that people shouldn't use the "_and_get" version. > > I went and added some pr_info() calls to verify that these were being > leaked before and they're fixed now. > > I copy-pasted this mistake into > https://lore.kernel.org/linux-kselftest/20210831171926.3832806-2-dlatypov@google.com/. > I'll send a v3 fix for that patch as well.
Fixed that patch: https://lore.kernel.org/linux-kselftest/20210909171052.3192326-2-dlatypov@google.com/
I assume this patch and that one shouldn't have merge conflicts, so we don't need these to be applied in any specific order.
> > > --- > > lib/kunit/executor_test.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/lib/kunit/executor_test.c b/lib/kunit/executor_test.c > > index cdbe54b16501..c2dcfb1f6e97 100644 > > --- a/lib/kunit/executor_test.c > > +++ b/lib/kunit/executor_test.c > > @@ -116,7 +116,7 @@ static void kfree_at_end(struct kunit *test, const void *to_free) > > /* kfree() handles NULL already, but avoid allocating a no-op cleanup. */ > > if (IS_ERR_OR_NULL(to_free)) > > return; > > - kunit_alloc_and_get_resource(test, NULL, kfree_res_free, GFP_KERNEL, > > + kunit_alloc_resource(test, NULL, kfree_res_free, GFP_KERNEL, > > (void *)to_free); > > } > > > > -- > > 2.7.4 > > > > -- > > You received this message because you are subscribed to the Google Groups "KUnit Development" group. > > To unsubscribe from this group and stop receiving emails from it, send an email to kunit-dev+unsubscribe@googlegroups.com. > > To view this discussion on the web visit https://groups.google.com/d/msgid/kunit-dev/1631172276-82914-1-git-send-email-xiyuyang19%40fudan.edu.cn.
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