diff options
| author | Jan Kara <jack@suse.cz> | 2022-04-01 13:27:45 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-04-18 04:34:20 +0300 |
| commit | ea591cd4eb270393810e7be01feb8fde6a34fbbe (patch) | |
| tree | c6a54e9ebc04cc05ca5652e7e1564224425a74a6 | |
| parent | 3bc5e683c67d94bd839a1da2e796c15847b51b69 (diff) | |
| download | linux-ea591cd4eb270393810e7be01feb8fde6a34fbbe.tar.xz | |
bfq: Update cgroup information before merging bio
When the process is migrated to a different cgroup (or in case of
writeback just starts submitting bios associated with a different
cgroup) bfq_merge_bio() can operate with stale cgroup information in
bic. Thus the bio can be merged to a request from a different cgroup or
it can result in merging of bfqqs for different cgroups or bfqqs of
already dead cgroups and causing possible use-after-free issues. Fix the
problem by updating cgroup information in bfq_merge_bio().
CC: stable@vger.kernel.org
Fixes: e21b7a0b9887 ("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/20220401102752.8599-4-jack@suse.cz
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/bfq-iosched.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 89fe3f85eb3c..1fc4d4628fba 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -2457,10 +2457,17 @@ static bool bfq_bio_merge(struct request_queue *q, struct bio *bio, spin_lock_irq(&bfqd->lock); - if (bic) + if (bic) { + /* + * Make sure cgroup info is uptodate for current process before + * considering the merge. + */ + bfq_bic_update_cgroup(bic, bio); + bfqd->bio_bfqq = bic_to_bfqq(bic, op_is_sync(bio->bi_opf)); - else + } else { bfqd->bio_bfqq = NULL; + } bfqd->bio_bic = bic; ret = blk_mq_sched_try_merge(q, bio, nr_segs, &free); |