From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:49940 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730202AbeKLFsN (ORCPT ); Mon, 12 Nov 2018 00:48:13 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Kees Cook" , "Andrea Arcangeli" , "Konstantin Khlebnikov" , "Linus Torvalds" , "Alexander Viro" , "Chen Gang" , "Hector Marco-Gisbert" , "Michal Hocko" , "Kirill A. Shutemov" , "Ismael Ripoll Ripoll" , "Andrey Ryabinin" , "Oleg Nesterov" Date: Sun, 11 Nov 2018 19:49:05 +0000 Message-ID: Subject: [PATCH 3.16 252/366] mm: refuse wrapped vm_brk requests In-Reply-To: Sender: stable-owner@vger.kernel.org List-ID: 3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Kees Cook commit ba093a6d9397da8eafcfbaa7d95bd34255da39a0 upstream. 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.org Signed-off-by: Kees Cook Reported-by: Hector Marco-Gisbert Cc: Ismael Ripoll Ripoll Cc: Alexander Viro Cc: "Kirill A. Shutemov" Cc: Oleg Nesterov Cc: Chen Gang Cc: Michal Hocko Cc: Konstantin Khlebnikov Cc: Andrea Arcangeli Cc: Andrey Ryabinin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- mm/mmap.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2751,16 +2751,18 @@ static inline void verify_mm_writelocked * anonymous maps. eventually we may be able to do some * brk-specific accounting here. */ -static unsigned long do_brk(unsigned long addr, unsigned long len) +static unsigned long 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 addr;