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authorChen LinX <linx.z.chen@intel.com>2013-10-30 13:56:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-10-30 14:27:03 -0700
commit3017f079efd6af199b0852b5c425364513db460e (patch)
treeeea77c43f0d14bfe8f082365b0ec5921ed00e7bf
parent7314e613d5ff9f0934f7a0f74ed7973b903315d1 (diff)
downloadlinux-3017f079efd6af199b0852b5c425364513db460e.tar.gz
mm/pagewalk.c: fix walk_page_range() access of wrong PTEs
When walk_page_range walk a memory map's page tables, it'll skip VM_PFNMAP area, then variable 'next' will to assign to vma->vm_end, it maybe larger than 'end'. In next loop, 'addr' will be larger than 'next'. Then in /proc/XXXX/pagemap file reading procedure, the 'addr' will growing forever in pagemap_pte_range, pte_to_pagemap_entry will access the wrong pte. BUG: Bad page map in process procrank pte:8437526f pmd:785de067 addr:9108d000 vm_flags:00200073 anon_vma:f0d99020 mapping: (null) index:9108d CPU: 1 PID: 4974 Comm: procrank Tainted: G B W O 3.10.1+ #1 Call Trace: dump_stack+0x16/0x18 print_bad_pte+0x114/0x1b0 vm_normal_page+0x56/0x60 pagemap_pte_range+0x17a/0x1d0 walk_page_range+0x19e/0x2c0 pagemap_read+0x16e/0x200 vfs_read+0x84/0x150 SyS_read+0x4a/0x80 syscall_call+0x7/0xb Signed-off-by: Liu ShuoX <shuox.liu@intel.com> Signed-off-by: Chen LinX <linx.z.chen@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: <stable@vger.kernel.org> [3.10.x+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/pagewalk.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 5da2cbcfdbb..2beeabf502c 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -242,7 +242,7 @@ int walk_page_range(unsigned long addr, unsigned long end,
if (err)
break;
pgd++;
- } while (addr = next, addr != end);
+ } while (addr = next, addr < end);
return err;
}