Re: [PATCH 1/5] arm64: vdso: don't free unallocated pages

Mark Rutland
2020-04-15T13:03:49Z

On Wed, Apr 15, 2020 at 11:13:11AM +0100, Catalin Marinas wrote:
> On Tue, Apr 14, 2020 at 11:42:48AM +0100, Mark Rutland wrote:
> > The aarch32_vdso_pages[] array never has entries allocated in the C_VVAR
> > or C_VDSO slots, and as the array is zero initialized these contain
> > NULL.
> >
> > However in __aarch32_alloc_vdso_pages() when
> > aarch32_alloc_kuser_vdso_page() fails we attempt to free the page whose
> > struct page is at NULL, which is obviously nonsensical.
> >
> > This patch removes the erroneous page freeing.
> >
> > Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> > Cc: Catalin Marinas <catalin.marinas@arm.com>
> > Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
> > Cc: Will Deacon <will@kernel.org>
> > Cc: stable@vger.kernel.org
>
> I presume the cc stable should be limited to:
>
> Fixes: 7c1deeeb0130 ("arm64: compat: VDSO setup for compat layer")
> Cc: <stable@vger.kernel.org> # 5.3.x-
>
> I'll fix it up locally.

Yes, and thanks!

Mark.