Messages in this thread | | | From | Rob Herring <> | Date | Thu, 16 Dec 2021 11:12:42 -0600 | Subject | Re: [PATCH] drm/panfrost: Avoid user size passed to kvmalloc() |
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On Thu, Dec 16, 2021 at 10:16 AM Steven Price <steven.price@arm.com> wrote: > > panfrost_copy_in_sync() takes the number of fences from user space > (in_sync_count) and used to kvmalloc() an array to hold that number of > fences before processing them. This provides an easy method for user > space to trigger the OOM killer (by temporarily allocating large amounts > of kernel memory) or hit the WARN_ONCE() added by 7661809d493b ("mm: > don't allow oversized kvmalloc() calls"). > > Since we don't expect there to be a large number of fences we can > instead iterate over the fences one-by-one and avoid the temporary > allocation altogether. This also makes the code simpler.
Doesn't the BO lookup suffer from the same issue?
Rob
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