Allow stack to grow up to address space limit

commit bd726c90b6b8ce87602208701b208a208e6d5600 upstream.

Fix expand_upwards() on architectures with an upward-growing stack (parisc,
metag and partly IA-64) to allow the stack to reliably grow exactly up to
the address space limit given by TASK_SIZE.

Signed-off-by: Helge Deller <deller@gmx.de>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
CVE-2017-1000364
Signed-off-by: Kevin F. Haggerty <haggertk@lineageos.org>

Change-Id: I09ba5194a654bc3722f018063414169f0754b4d9
Signed-off-by: Kevin F. Haggerty <haggertk@lineageos.org>
This commit is contained in:
Helge Deller 2017-06-19 17:34:05 +02:00 committed by Francescodario Cuzzocrea
parent 8f965fea40
commit c701778327
1 changed files with 8 additions and 5 deletions

View File

@ -1867,16 +1867,19 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
* We must make sure the anon_vma is allocated
* so that the anon_vma locking is not a noop.
*/
/* Guard against wrapping around to address 0. */
/* Guard against exceeding limits of the address space. */
address &= PAGE_MASK;
address += PAGE_SIZE;
if (!address)
if (address >= TASK_SIZE)
return -ENOMEM;
address += PAGE_SIZE;
/* Enforce stack_guard_gap */
gap_addr = address + stack_guard_gap;
if (gap_addr < address)
return -ENOMEM;
/* Guard against overflow */
if (gap_addr < address || gap_addr > TASK_SIZE)
gap_addr = TASK_SIZE;
next = vma->vm_next;
if (next && next->vm_start < gap_addr) {
if (!(next->vm_flags & VM_GROWSUP))