From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753336AbbIRKlQ (ORCPT ); Fri, 18 Sep 2015 06:41:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34304 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752436AbbIRKlO (ORCPT ); Fri, 18 Sep 2015 06:41:14 -0400 Date: Fri, 18 Sep 2015 13:41:09 +0300 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: "David S. Miller" , Matthew Rosato , Christian Borntraeger , Al Viro , Jason Wang , David Gibson , Greg Kurz , Vlad Yasevich , Justin Cormack , Herbert Xu , netdev@vger.kernel.org Subject: [PATCH] macvtap: fix TUNSETSNDBUF values > 64k Message-ID: <1442572808-6438-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Mutt-Fcc: =sent Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Upon TUNSETSNDBUF, macvtap reads the requested sndbuf size into a local variable u. commit 39ec7de7092b ("macvtap: fix uninitialized access on TUNSETIFF") changed its type to u16 (which is the right thing to do for all other macvtap ioctls), breaking all values > 64k. The value of TUNSETSNDBUF is actually a signed 32 bit integer, so the right thing to do is to read it into an int. Cc: David S. Miller Fixes: 39ec7de7092b ("macvtap: fix uninitialized access on TUNSETIFF") Reported-by: Mark A. Peloquin Bisected-by: Matthew Rosato Reported-by: Christian Borntraeger Signed-off-by: Michael S. Tsirkin --- This patch probably makes sense on stable. drivers/net/macvtap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index edd7734..248478c 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -1111,10 +1111,10 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd, return 0; case TUNSETSNDBUF: - if (get_user(u, up)) + if (get_user(s, sp)) return -EFAULT; - q->sk.sk_sndbuf = u; + q->sk.sk_sndbuf = s; return 0; case TUNGETVNETHDRSZ: -- MST