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 DB15C4431 for ; Wed, 15 Mar 2023 12:22:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5CCF9C433D2; Wed, 15 Mar 2023 12:22:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678882948; bh=4PQPPlT5tXd+qzAnGnFVVyBNzxdAoH2Tpguhmr4Eo/w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Gt2YJ7e8c1vG7YgQytlJIDF0XTlDYkh5IxKYd7u83pgWNn2O1JznWt6Wony7RdryM xs/cBPmcvJGaSECsw3xdVWByNSrH09B57VC7KkAxapKJeEuvLUqNoGcB3YlAHDm8iC 7TUJbMr8uubDDo4hVqlA0sCbSl/e86LyO/bNihCs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yi Zhang , Yu Kuai , Jens Axboe , Sasha Levin , Khazhismel Kumykov Subject: [PATCH 5.10 062/104] block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq Date: Wed, 15 Mar 2023 13:12:33 +0100 Message-Id: <20230315115734.552502207@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 246cf66e300b76099b5dbd3fdd39e9a5dbc53f02 ] Commit 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'") will access 'bic->bfqq' in bic_set_bfqq(), however, bfq_exit_icq_bfqq() can free bfqq first, and then call bic_set_bfqq(), which will cause uaf. Fix the problem by moving bfq_exit_bfqq() behind bic_set_bfqq(). Fixes: 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'") Reported-by: Yi Zhang Signed-off-by: Yu Kuai Link: https://lore.kernel.org/r/20221226030605.1437081-1-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-iosched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index afaededb3c49c..0a53b653a7e2e 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -4983,8 +4983,8 @@ static void bfq_exit_icq_bfqq(struct bfq_io_cq *bic, bool is_sync) unsigned long flags; spin_lock_irqsave(&bfqd->lock, flags); - bfq_exit_bfqq(bfqd, bfqq); bic_set_bfqq(bic, NULL, is_sync); + bfq_exit_bfqq(bfqd, bfqq); spin_unlock_irqrestore(&bfqd->lock, flags); } } -- 2.39.2