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Commit 3b9ba4d5 authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds
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[PATCH] x86_64: When checking vmalloc mappings don't use pte_page 



The PTEs can point to ioremap mappings too, and these are often outside
mem_map.  The NUMA hash page lookup functions cannot handle out of bounds
accesses properly.

Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent f6b8d477

arch/x86_64/mm/fault.c

+9 −2
Original line number Diff line number Diff line
@@ -234,6 +234,8 @@ static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs, 


/*

 * Handle a fault on the vmalloc or module mapping area

 *

 * This assumes no large pages in there.

 */

static int vmalloc_fault(unsigned long address)

{
@@ -272,7 +274,10 @@ static int vmalloc_fault(unsigned long address) 
	if (!pte_present(*pte_ref))

		return -1;

	pte = pte_offset_kernel(pmd, address);

	if (!pte_present(*pte) || pte_page(*pte) != pte_page(*pte_ref))

	/* Don't use pte_page here, because the mappings can point

	   outside mem_map, and the NUMA hash lookup cannot handle

	   that. */

	if (!pte_present(*pte) || pte_pfn(*pte) != pte_pfn(*pte_ref))

		BUG();

	__flush_tlb_all();

	return 0;
@@ -346,7 +351,9 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code) 
	 * protection error (error_code & 1) == 0.

	 */

	if (unlikely(address >= TASK_SIZE)) {

		if (!(error_code & 5)) {

		if (!(error_code & 5) &&

		      ((address >= VMALLOC_START && address < VMALLOC_END) ||

		       (address >= MODULES_VADDR && address < MODULES_END))) {

			if (vmalloc_fault(address) < 0)

				goto bad_area_nosemaphore;

			return;