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[PATCH] Check if start address is in vma region in NOMMU function get_user_pages()

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In NOMMU arch, if run "cat /proc/self/mem", data from physical address 0
are read.  This behavior is different from MMU arch.  In IA32, message
"cat: /proc/self/mem: Input/output error" is reported.

This issue is rootcaused by not validate the start address in NOMMU
function get_user_pages().  Following patch solves this issue.

Signed-off-by: Sonic Zhang <sonic.adi@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Sonic Zhang 2006-09-27 01:50:17 -07:00 committed by Linus Torvalds
parent 0159b141d8
commit 910e46da4b
1 changed files with 6 additions and 2 deletions
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8
mm/nommu.c
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@ -129,16 +129,20 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
struct page **pages, struct vm_area_struct **vmas) struct page **pages, struct vm_area_struct **vmas)
{ {
int i; int i;
static struct vm_area_struct dummy_vma; struct vm_area_struct *vma;
for (i = 0; i < len; i++) { for (i = 0; i < len; i++) {
vma = find_vma(mm, start);
if(!vma)
return i ? : -EFAULT;
if (pages) { if (pages) {
pages[i] = virt_to_page(start); pages[i] = virt_to_page(start);
if (pages[i]) if (pages[i])
page_cache_get(pages[i]); page_cache_get(pages[i]);
} }
if (vmas) if (vmas)
vmas[i] = &dummy_vma; vmas[i] = vma;
start += PAGE_SIZE; start += PAGE_SIZE;
} }
return(i); return(i);