mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

bfq: Make sure bfqg for which we are queueing requests is online 

commit 075a53b78b upstream.

Bios queued into BFQ IO scheduler can be associated with a cgroup that
was already offlined. This may then cause insertion of this bfq_group
into a service tree. But this bfq_group will get freed as soon as last
bio associated with it is completed leading to use after free issues for
service tree users. Fix the problem by making sure we always operate on
online bfq_group. If the bfq_group associated with the bio is not
online, we pick the first online parent.

CC: stable@vger.kernel.org
Fixes: e21b7a0b98 ("block, bfq: add full hierarchical scheduling and cgroups support")
Tested-by: "yukuai (C)" <yukuai3@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220401102752.8599-9-jack@suse.cz
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jan Kara 2022-04-01 12:27:50 +02:00 committed by Greg Kroah-Hartman
parent 3439a8271b
commit 97bd6c56bd
1 changed files with 12 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
block/bfq-cgroup.c
View File

@ -612,10 +612,19 @@ static void bfq_link_bfqg(struct bfq_data *bfqd, struct bfq_group *bfqg)
struct bfq_group *bfq_bio_bfqg(struct bfq_data *bfqd, struct bio *bio)
{
struct blkcg_gq *blkg = bio->bi_blkg;
struct bfq_group *bfqg;
if (!blkg)
return bfqd->root_group;
return blkg_to_bfqg(blkg);
while (blkg) {
bfqg = blkg_to_bfqg(blkg);
if (bfqg->online) {
bio_associate_blkg_from_css(bio, &blkg->blkcg->css);
return bfqg;
}
blkg = blkg->parent;
}
bio_associate_blkg_from_css(bio,
&bfqg_to_blkg(bfqd->root_group)->blkcg->css);
return bfqd->root_group;
}
/**