From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A97E54431 for ; Wed, 15 Mar 2023 12:22:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 30A09C433D2; Wed, 15 Mar 2023 12:22:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678882956; bh=VEJO0mu4Zr9obcBgVJ7JwhAuXNYrzStk8jsF/f6LWcc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VbTDtawXj/sDhiPNjbdt7IXiSvZGTj3xkJESMD+o+U5Hvc8E6Y/VeGTL1T7wx+IEM G3XAmL8GEajw3L3l+Y7WBLr+fanVp1wtO+ahR7RyV3/NXsaTQqpjYFlLcEb2iEWNK4 Vu279bplJk7f/GPywVP3lrHnqzleAquPLXMc+dZc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yu Kuai , Jan Kara , Jens Axboe , Sasha Levin , Khazhismel Kumykov , Shinichiro Kawasaki Subject: [PATCH 5.10 065/104] block, bfq: fix uaf for bfqq in bic_set_bfqq() Date: Wed, 15 Mar 2023 13:12:36 +0100 Message-Id: <20230315115734.670453825@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230315115731.942692602@linuxfoundation.org> References: <20230315115731.942692602@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Yu Kuai [ Upstream commit b600de2d7d3a16f9007fad1bdae82a3951a26af2 ] 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 Signed-off-by: Yu Kuai Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230130014136.591038-1-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin Signed-off-by: Khazhismel Kumykov Signed-off-by: Sasha Levin --- 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 2f440b79183d3..1f9ccc661d574 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -748,8 +748,8 @@ 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 016d7f32af9f1..6687b805bab3b 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -5070,9 +5070,11 @@ 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); bic_set_bfqq(bic, bfqq, false); + bfq_release_process_ref(bfqd, old_bfqq); } bfqq = bic_to_bfqq(bic, true); -- 2.39.2