Messages in this thread | | | Subject | Re: [V9fs-developer] [PATCH] net/9p: Modify the problem of BUG_ON judgment | From | jiangyiwen <> | Date | Fri, 3 Aug 2018 14:17:58 +0800 |
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On 2018/8/3 12:23, Dominique Martinet wrote: > jiangyiwen wrote on Fri, Aug 03, 2018: >> 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. >> >> Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com> > > I'm not sure you've acted on his mail or if you found this > independantly, but this was reported by Dan Carpenter on the list in > June. > Would you mind if I add a tag for him? > Reported-by: Dan Carpenter <dan.carpenter@oracle.com> > > That aside this looks good, I'll take it. >
Sorry, I didn't see it before, I tested this problem a few days ago. It is true that this problem was discovered first by him. Thank you for adding him.
>> --- >> net/9p/trans_virtio.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c >> index 6265d1d..08264ba 100644 >> --- a/net/9p/trans_virtio.c >> +++ b/net/9p/trans_virtio.c >> @@ -191,7 +191,7 @@ static int pack_sg_list(struct scatterlist *sg, int start, >> 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); >> @@ -236,6 +236,7 @@ static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req) >> 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); >
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