Messages in this thread | | | From | "Reshetova, Elena" <> | Subject | RE: [PATCH 1/3] [S390] vmur: convert urdev.ref_count from atomic_t to refcount_t | Date | Fri, 27 Oct 2017 06:35:35 +0000 |
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> On Fri, 20 Oct 2017 10:47:48 +0300 > Elena Reshetova <elena.reshetova@intel.com> wrote: > > > atomic_t variables are currently used to implement reference > > counters with the following properties: > > - counter is initialized to 1 using atomic_set() > > - a resource is freed upon counter reaching zero > > - once counter reaches zero, its further > > increments aren't allowed > > - counter schema uses basic atomic operations > > (set, inc, inc_not_zero, dec_and_test, etc.) > > > > Such atomic variables should be converted to a newly provided > > refcount_t type and API that prevents accidental counter overflows > > and underflows. This is important since overflows and underflows > > can lead to use-after-free situation and be exploitable. > > > > The variable urdev.ref_count is used as pure reference counter. > > Convert it to refcount_t and fix up the operations. > > > > Suggested-by: Kees Cook <keescook@chromium.org> > > Reviewed-by: David Windsor <dwindsor@gmail.com> > > Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com> > > Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> > > Added to s390/linux:features for the next merge window. Thanks.
Thank you very much!
Best Regards, Elena. > > -- > blue skies, > Martin. > > "Reality continues to ruin my life." - Calvin.
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