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authorDavid Howells <dhowells@redhat.com>2006-09-27 01:50:15 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-09-27 08:26:14 -0700
commit0ec76a110f432e98277e464b82ace8dd66571689 (patch)
tree3ed8de0ea6869fe17bec7689c493a2db02f73f4a /kernel/ptrace.c
parent361f6ed1d00f666a1a7c33f3e9aaccb713f9b9e4 (diff)
[PATCH] NOMMU: Check that access_process_vm() has a valid target
Check that access_process_vm() is accessing a valid mapping in the target process. This limits ptrace() accesses and accesses through /proc/<pid>/maps to only those regions actually mapped by a program. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/ptrace.c')
-rw-r--r--kernel/ptrace.c54
1 files changed, 0 insertions, 54 deletions
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 9a111f70145..8aad0331d82 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -241,60 +241,6 @@ int ptrace_detach(struct task_struct *child, unsigned int data)
return 0;
}
-/*
- * Access another process' address space.
- * Source/target buffer must be kernel space,
- * Do not walk the page table directly, use get_user_pages
- */
-
-int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write)
-{
- struct mm_struct *mm;
- struct vm_area_struct *vma;
- struct page *page;
- void *old_buf = buf;
-
- mm = get_task_mm(tsk);
- if (!mm)
- return 0;
-
- down_read(&mm->mmap_sem);
- /* ignore errors, just check how much was sucessfully transfered */
- while (len) {
- int bytes, ret, offset;
- void *maddr;
-
- ret = get_user_pages(tsk, mm, addr, 1,
- write, 1, &page, &vma);
- if (ret <= 0)
- break;
-
- bytes = len;
- offset = addr & (PAGE_SIZE-1);
- if (bytes > PAGE_SIZE-offset)
- bytes = PAGE_SIZE-offset;
-
- maddr = kmap(page);
- if (write) {
- copy_to_user_page(vma, page, addr,
- maddr + offset, buf, bytes);
- set_page_dirty_lock(page);
- } else {
- copy_from_user_page(vma, page, addr,
- buf, maddr + offset, bytes);
- }
- kunmap(page);
- page_cache_release(page);
- len -= bytes;
- buf += bytes;
- addr += bytes;
- }
- up_read(&mm->mmap_sem);
- mmput(mm);
-
- return buf - old_buf;
-}
-
int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
{
int copied = 0;