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arm64: vdso: don't free unallocated pages 

commit 9cc3d0c691 upstream.

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.

Fixes: 7c1deeeb01 ("arm64: compat: VDSO setup for compat layer")
Cc: <stable@vger.kernel.org> # 5.3.x-
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5.4-rM2-2.2.x-imx-squashed
Mark Rutland 2020-04-14 11:42:48 +01:00 committed by Greg Kroah-Hartman
parent 5209e5f05b
commit f32a339e03
1 changed files with 1 additions and 12 deletions
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13
arch/arm64/kernel/vdso.c
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@ -260,18 +260,7 @@ static int __aarch32_alloc_vdso_pages(void)
if (ret)
return ret;
ret = aarch32_alloc_kuser_vdso_page();
if (ret) {
unsigned long c_vvar =
(unsigned long)page_to_virt(aarch32_vdso_pages[C_VVAR]);
unsigned long c_vdso =
(unsigned long)page_to_virt(aarch32_vdso_pages[C_VDSO]);
free_page(c_vvar);
free_page(c_vdso);
}
return ret;
return aarch32_alloc_kuser_vdso_page();
}
#else
static int __aarch32_alloc_vdso_pages(void)