* [PATCH] block: Fix potential page reference leak in __bio_iov_append_get_pages()
@ 2020-09-05 9:40 Miaohe Lin
2020-09-09 7:09 ` Johannes Thumshirn
0 siblings, 1 reply; 3+ messages in thread
From: Miaohe Lin @ 2020-09-05 9:40 UTC (permalink / raw)
To: axboe, martin.petersen, kbusch, johannes.thumshirn, hare
Cc: linux-block, linux-kernel, linmiaohe
When bio_add_hw_page() failed, we left page reference still held in pages.
Release these references and advance the iov_iter according to what we
have done successfully yet.
Fixes: 0512a75b98f8 ("block: Introduce REQ_OP_ZONE_APPEND")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
block/bio.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/block/bio.c b/block/bio.c
index e113073958cb..a323a5446221 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1080,7 +1080,7 @@ static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter)
len = min_t(size_t, PAGE_SIZE - offset, left);
if (bio_add_hw_page(q, bio, page, len, offset,
max_append_sectors, &same_page) != len)
- return -EINVAL;
+ goto put_pages;
if (same_page)
put_page(page);
offset = 0;
@@ -1088,6 +1088,16 @@ static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter)
iov_iter_advance(iter, size);
return 0;
+put_pages:
+ iov_iter_advance(iter, size - left);
+ for (; left > 0; left -= len, i++) {
+ struct page *page = pages[i];
+
+ len = min_t(size_t, PAGE_SIZE - offset, left);
+ put_page(page);
+ offset = 0;
+ }
+ return -EINVAL;
}
/**
--
2.19.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] block: Fix potential page reference leak in __bio_iov_append_get_pages()
2020-09-05 9:40 [PATCH] block: Fix potential page reference leak in __bio_iov_append_get_pages() Miaohe Lin
@ 2020-09-09 7:09 ` Johannes Thumshirn
0 siblings, 0 replies; 3+ messages in thread
From: Johannes Thumshirn @ 2020-09-09 7:09 UTC (permalink / raw)
To: Miaohe Lin, axboe, martin.petersen, kbusch, hare
Cc: linux-block, linux-kernel
On 05/09/2020 11:41, Miaohe Lin wrote:
> When bio_add_hw_page() failed, we left page reference still held in pages.
I'd add "from iov_iter_get_pages()" to the above sentence.
Otherwise
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] block: Fix potential page reference leak in __bio_iov_append_get_pages()
@ 2020-09-09 7:21 linmiaohe
0 siblings, 0 replies; 3+ messages in thread
From: linmiaohe @ 2020-09-09 7:21 UTC (permalink / raw)
To: Johannes Thumshirn
Cc: linux-block, linux-kernel, axboe, martin.petersen, kbusch, hare
Johannes Thumshirn <Johannes.Thumshirn@wdc.com> wrote:
>On 05/09/2020 11:41, Miaohe Lin wrote:
>> When bio_add_hw_page() failed, we left page reference still held in pages.
>
>I'd add "from iov_iter_get_pages()" to the above sentence.
>
Sounds good. Will add it in v2.
>Otherwise
>Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Many Thanks for review.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2020-09-09 7:09 ` Johannes Thumshirn
2020-09-09 7:21 linmiaohe
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