Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755546Ab3I3KMs (ORCPT ); Mon, 30 Sep 2013 06:12:48 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:43571 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755439Ab3I3KMf (ORCPT ); Mon, 30 Sep 2013 06:12:35 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Dan Carpenter , "David S. Miller" , Luis Henriques Subject: [PATCH 048/104] tun: signedness bug in tun_get_user() Date: Mon, 30 Sep 2013 11:10:25 +0100 Message-Id: <1380535881-9239-49-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1380535881-9239-1-git-send-email-luis.henriques@canonical.com> References: <1380535881-9239-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1807 Lines: 56 3.5.7.22 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter commit 15718ea0d844e4816dbd95d57a8a0e3e264ba90e upstream. The recent fix d9bf5f1309 "tun: compare with 0 instead of total_len" is not totally correct. Because "len" and "sizeof()" are size_t type, that means they are never less than zero. Signed-off-by: Dan Carpenter Acked-by: Michael S. Tsirkin Acked-by: Neil Horman Signed-off-by: David S. Miller [ luis: backported to 3.5: adjusted context ] Signed-off-by: Luis Henriques --- drivers/net/tun.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 21c33f2..f21bcef 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -615,8 +615,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, int offset = 0; if (!(tun->flags & TUN_NO_PI)) { - if ((len -= sizeof(pi)) > count) + if (len < sizeof(pi)) return -EINVAL; + len -= sizeof(pi); if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi))) return -EFAULT; @@ -624,8 +625,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, } if (tun->flags & TUN_VNET_HDR) { - if ((len -= tun->vnet_hdr_sz) > count) + if (len < tun->vnet_hdr_sz) return -EINVAL; + len -= tun->vnet_hdr_sz; if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso))) return -EFAULT; -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/