Commit ba093a6d authored by Kees Cook's avatar Kees Cook Committed by Linus Torvalds

mm: refuse wrapped vm_brk requests

The vm_brk() alignment calculations should refuse to overflow.  The ELF
loader depending on this, but it has been fixed now.  No other unsafe
callers have been found.

Link: http://lkml.kernel.org/r/1468014494-25291-3-git-send-email-keescook@chromium.orgSigned-off-by: default avatarKees Cook <keescook@chromium.org>
Reported-by: default avatarHector Marco-Gisbert <hecmargi@upv.es>
Cc: Ismael Ripoll Ripoll <iripoll@upv.es>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Chen Gang <gang.chen.5i5j@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0036d1f7
......@@ -2653,16 +2653,18 @@ static inline void verify_mm_writelocked(struct mm_struct *mm)
* anonymous maps. eventually we may be able to do some
* brk-specific accounting here.
*/
static int do_brk(unsigned long addr, unsigned long len)
static int do_brk(unsigned long addr, unsigned long request)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma, *prev;
unsigned long flags;
unsigned long flags, len;
struct rb_node **rb_link, *rb_parent;
pgoff_t pgoff = addr >> PAGE_SHIFT;
int error;
len = PAGE_ALIGN(len);
len = PAGE_ALIGN(request);
if (len < request)
return -ENOMEM;
if (!len)
return 0;
......
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