From cc90bc68422318eb8e75b15cd74bc8d538a7df29 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Mon, 9 Dec 2019 20:11:14 +0100 Subject: block: fix "check bi_size overflow before merge" This partially reverts commit e3a5d8e386c3fb973fa75f2403622a8f3640ec06. Commit e3a5d8e386c3 ("check bi_size overflow before merge") adds a bio_full check to __bio_try_merge_page. This will cause __bio_try_merge_page to fail when the last bi_io_vec has been reached. Instead, what we want here is only the bi_size overflow check. Fixes: e3a5d8e386c3 ("block: check bi_size overflow before merge") Cc: stable@vger.kernel.org # v5.4+ Reviewed-by: Ming Lei Signed-off-by: Andreas Gruenbacher Signed-off-by: Jens Axboe --- block/bio.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'block') diff --git a/block/bio.c b/block/bio.c index 9d54aa37ce6c..a5d75f6bf4c7 100644 --- a/block/bio.c +++ b/block/bio.c @@ -754,10 +754,12 @@ bool __bio_try_merge_page(struct bio *bio, struct page *page, if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED))) return false; - if (bio->bi_vcnt > 0 && !bio_full(bio, len)) { + if (bio->bi_vcnt > 0) { struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1]; if (page_is_mergeable(bv, page, len, off, same_page)) { + if (bio->bi_iter.bi_size > UINT_MAX - len) + return false; bv->bv_len += len; bio->bi_iter.bi_size += len; return true; -- cgit