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bio: fix page leak bio_add_hw_page failure

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__bio_iov_append_get_pages() doesn't put not appended pages on
bio_add_hw_page() failure, so potentially leaking them, fix it. Also, do
the same for __bio_iov_iter_get_pages(), even though it looks like it
can't be triggered by userspace in this case.

Fixes: 0512a75b98 ("block: Introduce REQ_OP_ZONE_APPEND")
Cc: stable@vger.kernel.org # 5.8+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1edfa6a2ffd66d55e6345a477df5387d2c1415d0.1626653825.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2021-07-19 11:53:00 +01:00 committed by Jens Axboe
parent c4b2b7d150
commit d9cf3bd531
1 changed files with 13 additions and 2 deletions
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15
block/bio.c
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@ -974,6 +974,14 @@ static int bio_iov_bvec_set_append(struct bio *bio, struct iov_iter *iter)
return 0;
}
static void bio_put_pages(struct page **pages, size_t size, size_t off)
{
size_t i, nr = DIV_ROUND_UP(size + (off & ~PAGE_MASK), PAGE_SIZE);
for (i = 0; i < nr; i++)
put_page(pages[i]);
}
#define PAGE_PTRS_PER_BVEC (sizeof(struct bio_vec) / sizeof(struct page *))
/**
@ -1018,8 +1026,10 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
if (same_page)
put_page(page);
} else {
if (WARN_ON_ONCE(bio_full(bio, len)))
return -EINVAL;
if (WARN_ON_ONCE(bio_full(bio, len))) {
bio_put_pages(pages + i, left, offset);
return -EINVAL;
}
__bio_add_page(bio, page, len, offset);
}
offset = 0;
@ -1064,6 +1074,7 @@ 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) {
bio_put_pages(pages + i, left, offset);
ret = -EINVAL;
break;
}