Commit f4e97f5d authored Apr 12, 2019 by Gao Xiang Committed by Greg Kroah-Hartman Apr 16, 2019

staging: erofs: fix unexpected out-of-bound data access

Unexpected out-of-bound data will be read in erofs_read_raw_page
after commit 07173c3e ("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 <ming.lei@redhat.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Fixes: 07173c3e ("block: enable multipage bvecs")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 663d294b

drivers/staging/erofs/data.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -298,7 +298,7 @@ static inline struct bio erofs_read_raw_page(struct bio bio,
	*last_block = current_block;		*last_block = current_block;

	/* shift in advance in case of it followed by too many gaps */		/* 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 should reassign to 0 after submitting */
	err = 0;		err = 0;
	goto submit_bio_out;		goto submit_bio_out;