path: root/mm/pagewalk.c
diff options
authorChen LinX <>2013-10-30 13:56:18 -0700
committerLinus Torvalds <>2013-10-30 14:27:03 -0700
commit3017f079efd6af199b0852b5c425364513db460e (patch)
treeeea77c43f0d14bfe8f082365b0ec5921ed00e7bf /mm/pagewalk.c
parent7314e613d5ff9f0934f7a0f74ed7973b903315d1 (diff)
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 <> Signed-off-by: Chen LinX <> Acked-by: Kirill A. Shutemov <> Reviewed-by: Naoya Horiguchi <> Cc: <> [3.10.x+] Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'mm/pagewalk.c')
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 5da2cbcfdbb5..2beeabf502c5 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)
- } while (addr = next, addr != end);
+ } while (addr = next, addr < end);
return err;