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 46FC12C9C for ; Tue, 7 Feb 2023 13:10:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC041C433EF; Tue, 7 Feb 2023 13:10:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675775413; bh=6jbNHd1eQUoxntpkfl8uJxx3uT68UlEhaqwE7kSFWFI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rVovZDsHo/4Gua4KQc7cIYvZaMionMtbPxJA69Enlg5hGnjD6Sf8f/lC7vCz0vsed ScQnv2XysEuky7X3Lb2GWBo4x5exkc9vhRPAO5HcfmugptMgFRIs3XdLm1MaYXIDVw NHMgCQ8/tYvhCRP3CmOp/scelgeluAEeNOyRYy2s= 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 , Shinichiro Kawasaki Subject: [PATCH 5.15 031/120] block, bfq: fix uaf for bfqq in bic_set_bfqq() Date: Tue, 7 Feb 2023 13:56:42 +0100 Message-Id: <20230207125620.111998525@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230207125618.699726054@linuxfoundation.org> References: <20230207125618.699726054@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 --- 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 4ac6f59a3679..53e275e377a7 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -756,8 +756,8 @@ 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 8d967a67318c..f54554906451 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -5359,9 +5359,11 @@ 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); -- 2.39.0