From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f49.google.com (mail-ee0-f49.google.com [74.125.83.49]) by kanga.kvack.org (Postfix) with ESMTP id 90D5E6B003A for ; Mon, 21 Apr 2014 10:31:46 -0400 (EDT) Received: by mail-ee0-f49.google.com with SMTP id c41so3686617eek.36 for ; Mon, 21 Apr 2014 07:31:46 -0700 (PDT) Received: from mail-ee0-f43.google.com (mail-ee0-f43.google.com [74.125.83.43]) by mx.google.com with ESMTPS id u5si54783852een.113.2014.04.21.07.31.44 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 21 Apr 2014 07:31:45 -0700 (PDT) Received: by mail-ee0-f43.google.com with SMTP id e53so3666768eek.16 for ; Mon, 21 Apr 2014 07:31:44 -0700 (PDT) From: Manfred Spraul Subject: [PATCH 2/4] ipc/shm.c: check for overflows of shm_tot Date: Mon, 21 Apr 2014 16:26:35 +0200 Message-Id: <1398090397-2397-3-git-send-email-manfred@colorfullife.com> In-Reply-To: <1398090397-2397-2-git-send-email-manfred@colorfullife.com> References: <1398090397-2397-1-git-send-email-manfred@colorfullife.com> <1398090397-2397-2-git-send-email-manfred@colorfullife.com> Sender: owner-linux-mm@kvack.org List-ID: To: Davidlohr Bueso , Michael Kerrisk , Martin Schwidefsky Cc: LKML , Andrew Morton , KAMEZAWA Hiroyuki , KOSAKI Motohiro , gthelen@google.com, aswin@hp.com, linux-mm@kvack.org, Manfred Spraul shm_tot counts the total number of pages used by shm segments. If SHMALL is ULONG_MAX (or nearly ULONG_MAX), then the number can overflow. Subsequent calls to shmctl(,SHM_INFO,) would return wrong values for shm_tot. The patch adds a detection for overflows. Signed-off-by: Manfred Spraul --- ipc/shm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/ipc/shm.c b/ipc/shm.c index 382e2fb..2dfa3d6 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -493,7 +493,8 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) if (size < SHMMIN || size > ns->shm_ctlmax) return -EINVAL; - if (ns->shm_tot + numpages > ns->shm_ctlall) + if (ns->shm_tot + numpages < ns->shm_tot || + ns->shm_tot + numpages > ns->shm_ctlall) return -ENOSPC; shp = ipc_rcu_alloc(sizeof(*shp)); -- 1.9.0 -- 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