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Subject[patch 15/16] x86_64: When checking vmalloc mappings don't use pte_page
[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: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Chris Wright <chrisw@osdl.org>
---

fault.c | 11 +++++++++--
1 files changed, 9 insertions(+), 2 deletions(-)

Index: release-2.6.11/arch/x86_64/mm/fault.c
===================================================================
--- release-2.6.11.orig/arch/x86_64/mm/fault.c
+++ release-2.6.11/arch/x86_64/mm/fault.c
@@ -236,6 +236,8 @@ static noinline void pgtable_bad(unsigne

/*
* Handle a fault on the vmalloc or module mapping area
+ *
+ * This assumes no large pages in there.
*/
static int vmalloc_fault(unsigned long address)
{
@@ -274,7 +276,10 @@ static int vmalloc_fault(unsigned long a
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;
@@ -348,7 +353,9 @@ asmlinkage void do_page_fault(struct pt_
* 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;
-
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