4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: jiangyiwen <jiangyiwen@xxxxxxxxxx> 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@xxxxxxxxxx Signed-off-by: Yiwen Jiang <jiangyiwen@xxxxxxxxxx> Reported-By: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Acked-by: Jun Piao <piaojun@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Dominique Martinet <dominique.martinet@xxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -188,7 +188,7 @@ 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); @@ -233,6 +233,7 @@ 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);
