From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f48.google.com (mail-ee0-f48.google.com [74.125.83.48]) by kanga.kvack.org (Postfix) with ESMTP id 290956B0070 for ; Wed, 23 Apr 2014 01:05:52 -0400 (EDT) Received: by mail-ee0-f48.google.com with SMTP id b57so287189eek.35 for ; Tue, 22 Apr 2014 22:05:51 -0700 (PDT) Received: from mail-ee0-x22b.google.com (mail-ee0-x22b.google.com [2a00:1450:4013:c00::22b]) by mx.google.com with ESMTPS id z2si1326155eeo.64.2014.04.22.22.05.50 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 22 Apr 2014 22:05:50 -0700 (PDT) Received: by mail-ee0-f43.google.com with SMTP id e53so290897eek.30 for ; Tue, 22 Apr 2014 22:05:50 -0700 (PDT) Message-ID: <53574867.5010108@gmail.com> Date: Wed, 23 Apr 2014 06:58:15 +0200 From: "Michael Kerrisk (man-pages)" MIME-Version: 1.0 Subject: Re: [PATCH 1/4] ipc/shm.c: check for ulong overflows in shmat References: <1398090397-2397-1-git-send-email-manfred@colorfullife.com> <1398090397-2397-2-git-send-email-manfred@colorfullife.com> In-Reply-To: <1398090397-2397-2-git-send-email-manfred@colorfullife.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Manfred Spraul , Davidlohr Bueso , Martin Schwidefsky Cc: mtk.manpages@gmail.com, LKML , Andrew Morton , KAMEZAWA Hiroyuki , KOSAKI Motohiro , gthelen@google.com, aswin@hp.com, linux-mm@kvack.org On 04/21/2014 04:26 PM, Manfred Spraul wrote: > find_vma_intersection does not work as intended if addr+size overflows. > The patch adds a manual check before the call to find_vma_intersection. > > Signed-off-by: Manfred Spraul > --- > ipc/shm.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/ipc/shm.c b/ipc/shm.c > index 7645961..382e2fb 100644 > --- a/ipc/shm.c > +++ b/ipc/shm.c > @@ -1160,6 +1160,9 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr, > down_write(¤t->mm->mmap_sem); > if (addr && !(shmflg & SHM_REMAP)) { > err = -EINVAL; > + if (addr + size < addr) > + goto invalid; > + > if (find_vma_intersection(current->mm, addr, addr + size)) > goto invalid; > /* > Acked-by: Michael Kerrisk -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org