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| author | Yu Kuai <yukuai3@huawei.com> | 2023-01-30 09:41:36 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-01-29 18:57:01 -0700 |
| commit | b600de2d7d3a16f9007fad1bdae82a3951a26af2 (patch) | |
| tree | 4a676a3d482d0f4e89c2468d341b28895d62d26e /block/bfq-cgroup.c | |
| parent | db3ba974c2bc895ba39689a364cb7a49c0fe779f (diff) | |
| download | lwn-b600de2d7d3a16f9007fad1bdae82a3951a26af2.tar.gz lwn-b600de2d7d3a16f9007fad1bdae82a3951a26af2.zip | |
block, bfq: fix uaf for bfqq in bic_set_bfqq()
After commit 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'"),
bic->bfqq will be accessed in bic_set_bfqq(), however, in some context
bic->bfqq will be freed, and bic_set_bfqq() is called with the freed
bic->bfqq.
Fix the problem by always freeing bfqq after bic_set_bfqq().
Fixes: 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'")
Reported-and-tested-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230130014136.591038-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bfq-cgroup.c')
| -rw-r--r-- | block/bfq-cgroup.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index 7d9b15f0dbd5..0fbde0fc0628 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -769,8 +769,8 @@ static void __bfq_bic_change_cgroup(struct bfq_data *bfqd, * request from the old cgroup. */ bfq_put_cooperator(sync_bfqq); - bfq_release_process_ref(bfqd, sync_bfqq); bic_set_bfqq(bic, NULL, true); + bfq_release_process_ref(bfqd, sync_bfqq); } } } |