From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120518212650.137110817@linuxfoundation.org> Date: Fri, 18 May 2012 14:26:59 -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, Al Viro , Russell King Subject: [ 10/47] ARM: prevent VM_GROWSDOWN mmaps extending below FIRST_USER_ADDRESS In-Reply-To: <20120518212701.GA5023@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Russell King commit 9b61a4d1b2064dbd0c9e61754305ac852170509f upstream. Reported-by: Al Viro Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman --- arch/arm/mm/fault.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -245,7 +245,9 @@ good_area: return handle_mm_fault(mm, vma, addr & PAGE_MASK, flags); check_stack: - if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) + /* Don't allow expansion below FIRST_USER_ADDRESS */ + if (vma->vm_flags & VM_GROWSDOWN && + addr >= FIRST_USER_ADDRESS && !expand_stack(vma, addr)) goto good_area; out: return fault;