From: Pavel Begunkov asml.silence@gmail.com
commit d9cf3bd531844ffbfe94b16e417037a16efc988d upstream.
__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: 0512a75b98f8 ("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/1edfa6a2ffd66d55e6345a477df5387d2c1415d0.162665382... Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- block/bio.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-)
--- a/block/bio.c +++ b/block/bio.c @@ -979,6 +979,14 @@ static int bio_iov_bvec_set_append(struc 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 *))
/** @@ -1023,8 +1031,10 @@ static int __bio_iov_iter_get_pages(stru 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; @@ -1069,6 +1079,7 @@ static int __bio_iov_append_get_pages(st 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; }