Messages in this thread | | | From | Kees Cook <> | Date | Wed, 20 Jun 2018 16:43:14 -0700 | Subject | Re: [PATCH] platform/x86: wmi: Do not mix pages and kmalloc |
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On Wed, Jun 20, 2018 at 4:37 PM, Darren Hart <dvhart@infradead.org> wrote: > On Wed, Jun 20, 2018 at 02:31:41PM -0700, Kees Cook wrote: >> The probe handler_data was being allocated with __get_free_pages() >> for no reason I could find. The error path was using kfree(). Since > > v4 of Mario's series used kmalloc: > https://patchwork.kernel.org/patch/9985827/ > > This was changed in v10 to use __get_free_pages: > https://patchwork.kernel.org/patch/10018023/ > > But... I'm not finding the discussion that led to this change.... Mario, > do you recall? Something about contiguous memory? We had a similar > discussion on an earlier series: > > https://patchwork.kernel.org/patch/9975277/
FWIW, kmalloc gets you contiguous memory...
But if the reason is found and needs to stay, the probe error path's kfree() needs to be fixed, and __GFP_COMP needs to be added to the free page flags.
-Kees
-- Kees Cook Pixel Security
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