From 523632cf3d861b54949d1056e022e4826d3b1c12 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Tue, 5 Jan 2021 16:54:11 +0530 Subject: [PATCH] arm64/mm: Add warning for outside range requests in vmemmap_populate() vmemmap_populate() does not validate the requested vmemmap address range to be inside the platform assigned space i.e [VMEMMAP_START..VMEMMAP_END] for vmemmap. Instead it would just go ahead and create the mapping which might then overlap with other sections in the kernel virtual address space. Just adding an warning here for range overrun which would help detect the problem earlier on, before a potential struct page corruption. This also makes vmemmap_populate() symmetrical with vmemmap_free() which already has a similar warning. Cc: Catalin Marinas Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual Link: https://lore.kernel.org/r/1609845851-25064-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Will Deacon --- arch/arm64/mm/mmu.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index ae0c3d023824e..f938e80205237 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1094,6 +1094,7 @@ static void free_empty_tables(unsigned long addr, unsigned long end, int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, struct vmem_altmap *altmap) { + WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END)); return vmemmap_populate_basepages(start, end, node, altmap); } #else /* !ARM64_SWAPPER_USES_SECTION_MAPS */ @@ -1107,6 +1108,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, pud_t *pudp; pmd_t *pmdp; + WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END)); do { next = pmd_addr_end(addr, end); -- 2.39.5