[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <20230130014136.591038-1-yukuai1@huaweicloud.com>
Date: Mon, 30 Jan 2023 09:41:36 +0800
From: Yu Kuai <yukuai1@...weicloud.com>
To: tj@...nel.org, josef@...icpanda.com, axboe@...nel.dk,
paolo.valente@...aro.org, yukuai3@...wei.com, jack@...e.cz
Cc: cgroups@...r.kernel.org, linux-block@...r.kernel.org,
linux-kernel@...r.kernel.org, yukuai1@...weicloud.com,
yi.zhang@...wei.com, yangerkun@...wei.com
Subject: [PATCH v2 block-6.2] block, bfq: fix uaf for bfqq in bic_set_bfqq()
From: Yu Kuai <yukuai3@...wei.com>
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@....com>
Signed-off-by: Yu Kuai <yukuai3@...wei.com>
Reviewed-by: Jan Kara <jack@...e.cz>
---
block/bfq-cgroup.c | 2 +-
block/bfq-iosched.c | 4 +++-
2 files changed, 4 insertions(+), 2 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);
}
}
}
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index ccf2204477a5..380e9bda2e57 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5425,9 +5425,11 @@ static void bfq_check_ioprio_change(struct bfq_io_cq *bic, struct bio *bio)
bfqq = bic_to_bfqq(bic, false);
if (bfqq) {
- bfq_release_process_ref(bfqd, bfqq);
+ struct bfq_queue *old_bfqq = bfqq;
+
bfqq = bfq_get_queue(bfqd, bio, false, bic, true);
bic_set_bfqq(bic, bfqq, false);
+ bfq_release_process_ref(bfqd, old_bfqq);
}
bfqq = bic_to_bfqq(bic, true);
--
2.31.1
Powered by blists - more mailing lists