From f4e97f5d4c9ece362b9379d3158cf5e4c02404dc Mon Sep 17 00:00:00 2001 From: Gao Xiang Date: Fri, 12 Apr 2019 17:53:14 +0800 Subject: [PATCH] staging: erofs: fix unexpected out-of-bound data access Unexpected out-of-bound data will be read in erofs_read_raw_page after commit 07173c3ec276 ("block: enable multipage bvecs") since one iovec could have multiple pages. Let's fix as what Ming's pointed out in the previous email [1]. [1] https://lore.kernel.org/lkml/20190411080953.GE421@ming.t460p/ Suggested-by: Ming Lei Reviewed-by: Chao Yu Signed-off-by: Gao Xiang Fixes: 07173c3ec276 ("block: enable multipage bvecs") Signed-off-by: Greg Kroah-Hartman --- drivers/staging/erofs/data.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/erofs/data.c b/drivers/staging/erofs/data.c index 526e0dbea5b5..81af768e7248 100644 --- a/drivers/staging/erofs/data.c +++ b/drivers/staging/erofs/data.c @@ -298,7 +298,7 @@ static inline struct bio *erofs_read_raw_page(struct bio *bio, *last_block = current_block; /* shift in advance in case of it followed by too many gaps */ - if (unlikely(bio->bi_vcnt >= bio->bi_max_vecs)) { + if (bio->bi_iter.bi_size >= bio->bi_max_vecs * PAGE_SIZE) { /* err should reassign to 0 after submitting */ err = 0; goto submit_bio_out;