From patchwork Wed May 15 12:51:34 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baokun Li X-Patchwork-Id: 13665226 Received: from dggsgout11.his.huawei.com (unknown [45.249.212.51]) (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 80A0E129A8E; Wed, 15 May 2024 13:02:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715778140; cv=none; b=Us+t5EJEraJJ4FytJ1Ip8oKoSh4L9WPn5ioPvVteijlxmBtHfxG4UYTL8bUDQNDSWalvHEY5xiPubfy15cAu7PY77U3mqG/nrzFXhgBNDmgZo9OlaJQglyMUw3B5Qm30qQ93EF07j/8GuZZgt0zqzk3WcrGHppTzgD0NDZFFqiM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715778140; c=relaxed/simple; bh=nflcIOvlerrwIrtNuVpU2TiKnKICjvGJg4o0sDMaUp0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=eC4xwYQ6Igq9e+2uL27bBV6mDO95gIG7xfU4IAg738DQ9u2j+ZXcD8BN/QodZ9cpo5096yMjmiSfn25j3zqrKH3S82NUdlohDCjCY4usZTmYsnr03retegDsmmizkAg1uKyHrFFP2SKJ0nvISpYo/1oUIzooEtF88H0RDlehS1I= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4VfYK76hDZz4f3k6L; Wed, 15 May 2024 21:02:03 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id 7B32A1A0181; Wed, 15 May 2024 21:02:09 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP1 (Coremail) with SMTP id cCh0CgAX6RFLskRmALLwMg--.18738S7; Wed, 15 May 2024 21:02:09 +0800 (CST) From: libaokun@huaweicloud.com To: netfs@lists.linux.dev, dhowells@redhat.com, jlayton@kernel.org Cc: hsiangkao@linux.alibaba.com, jefflexu@linux.alibaba.com, zhujia.zj@bytedance.com, linux-erofs@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, libaokun@huaweicloud.com, yangerkun@huawei.com, houtao1@huawei.com, yukuai3@huawei.com, wozizhi@huawei.com, Baokun Li Subject: [PATCH v2 3/5] cachefiles: flush ondemand_object_worker during clean object Date: Wed, 15 May 2024 20:51:34 +0800 Message-Id: <20240515125136.3714580-4-libaokun@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240515125136.3714580-1-libaokun@huaweicloud.com> References: <20240515125136.3714580-1-libaokun@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: cCh0CgAX6RFLskRmALLwMg--.18738S7 X-Coremail-Antispam: 1UD129KBjvJXoW7Ww4kur4fJF1DXFy7Zw1UKFg_yoW8uryUpF WakFy7KrW8WF4UCrWkZFs5JryrK3ykZFnrWFyYvrZ8Ar90qr4rZr12y3ZxXF15Aw1SgrZr tw4UCr9xt34qy3DanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPK14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWUuVWrJwAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JrWl82xGYIkIc2 x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS 0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2 IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0 Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2kIc2 xKxwAKzVCY07xG64k0F24l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1l x2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14 v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IY x2IY6xkF7I0E14v26F4j6r4UJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z2 80aVAFwI0_Gr0_Cr1lIxAIcVC2z280aVCY1x0267AKxVW8Jr0_Cr1UYxBIdaVFxhVjvjDU 0xZFpf9x0JUPHUDUUUUU= X-CM-SenderInfo: 5olet0hnxqqx5xdzvxpfor3voofrz/ From: Hou Tao When queuing ondemand_object_worker() to re-open the object, cachefiles_object is not pinned. The cachefiles_object may be freed when the pending read request is completed intentionally and the related erofs is umounted. If ondemand_object_worker() runs after the object is freed, it will incur use-after-free problem as shown below. process A processs B process C process D cachefiles_ondemand_send_req() // send a read req X // wait for its completion // close ondemand fd cachefiles_ondemand_fd_release() // set object as CLOSE cachefiles_ondemand_daemon_read() // set object as REOPENING queue_work(fscache_wq, &info->ondemand_work) // close /dev/cachefiles cachefiles_daemon_release cachefiles_flush_reqs complete(&req->done) // read req X is completed // umount the erofs fs cachefiles_put_object() // object will be freed cachefiles_ondemand_deinit_obj_info() kmem_cache_free(object) // both info and object are freed ondemand_object_worker() When dropping an object, it is no longer necessary to reopen the object, so use cancel_work_sync() to cancel or wait for ondemand_object_worker() to complete. Fixes: 0a7e54c1959c ("cachefiles: resend an open request if the read request's object is closed") Signed-off-by: Hou Tao Signed-off-by: Baokun Li Reviewed-by: Jia Zhu --- fs/cachefiles/ondemand.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c index d24bff43499b..f6440b3e7368 100644 --- a/fs/cachefiles/ondemand.c +++ b/fs/cachefiles/ondemand.c @@ -589,6 +589,9 @@ void cachefiles_ondemand_clean_object(struct cachefiles_object *object) } } xa_unlock(&cache->reqs); + + /* Wait for ondemand_object_worker() to finish to avoid UAF. */ + cancel_work_sync(&object->ondemand->ondemand_work); } int cachefiles_ondemand_init_obj_info(struct cachefiles_object *object,