From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20111102221459.650206488@clark.kroah.org> Date: Wed, 02 Nov 2011 15:15:10 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Hugh Dickins Subject: [104/107] vm: fix vm_pgoff wrap in upward expansion In-Reply-To: <20111102221600.GA26650@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 2.6.32-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Hugh Dickins commit 42c36f63ac1366ab0ecc2d5717821362c259f517 upstream. Commit a626ca6a6564 ("vm: fix vm_pgoff wrap in stack expansion") fixed the case of an expanding mapping causing vm_pgoff wrapping when you had downward stack expansion. But there was another case where IA64 and PA-RISC expand mappings: upward expansion. This fixes that case too. Signed-off-by: Hugh Dickins Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/mmap.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1636,9 +1636,12 @@ int expand_upwards(struct vm_area_struct size = address - vma->vm_start; grow = (address - vma->vm_end) >> PAGE_SHIFT; - error = acct_stack_growth(vma, size, grow); - if (!error) - vma->vm_end = address; + error = -ENOMEM; + if (vma->vm_pgoff + (size >> PAGE_SHIFT) >= vma->vm_pgoff) { + error = acct_stack_growth(vma, size, grow); + if (!error) + vma->vm_end = address; + } } anon_vma_unlock(vma); return error;