Commit 3017f079 authored by Chen LinX's avatar Chen LinX Committed by Linus Torvalds

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: default avatarLiu ShuoX <shuox.liu@intel.com>
Signed-off-by: default avatarChen LinX <linx.z.chen@intel.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>	[3.10.x+]
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7314e613
......@@ -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;
}
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment