From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yiwen Jiang , Dan Carpenter , Jun Piao , Dominique Martinet Subject: [PATCH 4.9 16/63] 9p/virtio: fix off-by-one error in sg list bounds check Date: Fri, 7 Sep 2018 23:09:47 +0200 Message-Id: <20180907211013.898746517@linuxfoundation.org> In-Reply-To: <20180907211012.965501324@linuxfoundation.org> References: <20180907211012.965501324@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: jiangyiwen commit 23cba9cbde0bba05d772b335fe5f66aa82b9ad19 upstream. Because the value of limit is VIRTQUEUE_NUM, if index is equal to limit, it will cause sg array out of bounds, so correct the judgement of BUG_ON. Link: http://lkml.kernel.org/r/5B63D5F6.6080109@huawei.com Signed-off-by: Yiwen Jiang Reported-By: Dan Carpenter Acked-by: Jun Piao Cc: stable@vger.kernel.org Signed-off-by: Dominique Martinet Signed-off-by: Greg Kroah-Hartman --- net/9p/trans_virtio.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -189,7 +189,7 @@ static int pack_sg_list(struct scatterli s = rest_of_page(data); if (s > count) s = count; - BUG_ON(index > limit); + BUG_ON(index >= limit); /* Make sure we don't terminate early. */ sg_unmark_end(&sg[index]); sg_set_buf(&sg[index++], data, s); @@ -234,6 +234,7 @@ pack_sg_list_p(struct scatterlist *sg, i s = PAGE_SIZE - data_off; if (s > count) s = count; + BUG_ON(index >= limit); /* Make sure we don't terminate early. */ sg_unmark_end(&sg[index]); sg_set_page(&sg[index++], pdata[i++], s, data_off);