This fixes bio_add_page misuse in bio_copy_user_iov with rq_map_data,
which only sg uses now.
rq_map_data carries page frames for bio_add_pc_page. bio_copy_user_iov
uses bio_add_pc_page with a larger size than PAGE_SIZE. It's clearly
wrong.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Cc: Jens Axboe <jens.axboe@xxxxxxxxxx>
---
fs/bio.c | 26 ++++++++++++++------------
1 files changed, 14 insertions(+), 12 deletions(-)
diff --git a/fs/bio.c b/fs/bio.c
index 77a55bc..5fd6e98 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -662,28 +662,30 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
ret = 0;
i = 0;
+ if (map_data)
+ nr_pages = 1 << map_data->page_order;
while (len) {
- unsigned int bytes;
-
- if (map_data)
- bytes = 1U << (PAGE_SHIFT + map_data->page_order);
- else
- bytes = PAGE_SIZE;
+ unsigned int bytes = PAGE_SIZE;
if (bytes > len)
bytes = len;
if (map_data) {
- if (i == map_data->nr_entries) {
+ if (i == map_data->nr_entries * nr_pages) {
ret = -ENOMEM;
break;
}
- page = map_data->pages[i++];
- } else
+
+ page = map_data->pages[i / nr_pages];
+ page += (i % nr_pages);
+
+ i++;
+ } else {
page = alloc_page(q->bounce_gfp | gfp_mask);
- if (!page) {
- ret = -ENOMEM;
- break;
+ if (!page) {
+ ret = -ENOMEM;
+ break;
+ }
}
if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes)
--
1.5.6.5
--
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