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author | David Howells <dhowells@redhat.com> | 2006-09-27 01:50:15 -0700 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-09-27 08:26:14 -0700 |
commit | 0ec76a110f432e98277e464b82ace8dd66571689 (patch) | |
tree | 3ed8de0ea6869fe17bec7689c493a2db02f73f4a /kernel/ptrace.c | |
parent | 361f6ed1d00f666a1a7c33f3e9aaccb713f9b9e4 (diff) | |
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[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.c | 54 |
1 files changed, 0 insertions, 54 deletions
diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 9a111f7..8aad033 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; |