4.9-stable review patch. If anyone has any objections, please let me know.
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From: jiangyiwen jiangyiwen@huawei.com
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 jiangyiwen@huawei.com Reported-By: Dan Carpenter dan.carpenter@oracle.com Acked-by: Jun Piao piaojun@huawei.com Cc: stable@vger.kernel.org Signed-off-by: Dominique Martinet dominique.martinet@cea.fr Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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);