From patchwork Thu Oct 20 03:42:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhang Xiaoxu X-Patchwork-Id: 13012557 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C008C433FE for ; Thu, 20 Oct 2022 02:39:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230470AbiJTCjl (ORCPT ); Wed, 19 Oct 2022 22:39:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229933AbiJTCjj (ORCPT ); Wed, 19 Oct 2022 22:39:39 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 729B62F001 for ; Wed, 19 Oct 2022 19:39:32 -0700 (PDT) Received: from dggpeml500023.china.huawei.com (unknown [172.30.72.53]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4MtBZB4qkRzJn6f; Thu, 20 Oct 2022 10:36:50 +0800 (CST) Received: from localhost.localdomain (10.175.101.6) by dggpeml500023.china.huawei.com (7.185.36.114) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 20 Oct 2022 10:38:57 +0800 From: Zhang Xiaoxu To: , , , , , Subject: [PATCH] SUNRPC: Fix null-ptr-deref when xps sysfs alloc failed Date: Thu, 20 Oct 2022 11:42:17 +0800 Message-ID: <20221020034217.3289013-1-zhangxiaoxu5@huawei.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpeml500023.china.huawei.com (7.185.36.114) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org There is a null-ptr-deref when xps sysfs alloc failed: BUG: KASAN: null-ptr-deref in sysfs_do_create_link_sd+0x40/0xd0 Read of size 8 at addr 0000000000000030 by task gssproxy/457 CPU: 5 PID: 457 Comm: gssproxy Not tainted 6.0.0-09040-g02357b27ee03 #9 Call Trace: dump_stack_lvl+0x34/0x44 kasan_report+0xa3/0x120 sysfs_do_create_link_sd+0x40/0xd0 rpc_sysfs_client_setup+0x161/0x1b0 rpc_new_client+0x3fc/0x6e0 rpc_create_xprt+0x71/0x220 rpc_create+0x1d4/0x350 gssp_rpc_create+0xc3/0x160 set_gssp_clnt+0xbc/0x140 write_gssp+0x116/0x1a0 proc_reg_write+0xd6/0x130 vfs_write+0x177/0x690 ksys_write+0xb9/0x150 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 When the xprt_switch sysfs alloc failed, should not add xprt and switch sysfs to it, otherwise, maybe null-ptr-deref; also initialize the 'xps_sysfs' to NULL to avoid oops when destroy it. Fixes: 2a338a543163 ("sunrpc: add a symlink from rpc-client directory to the xprt_switch") Fixes: d408ebe04ac5 ("sunrpc: add add sysfs directory per xprt under each xprt_switch") Fixes: baea99445dd4 ("sunrpc: add xprt_switch direcotry to sunrpc's sysfs") Signed-off-by: Zhang Xiaoxu --- net/sunrpc/sysfs.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c index c65c90ad626a..c1f559892ae8 100644 --- a/net/sunrpc/sysfs.c +++ b/net/sunrpc/sysfs.c @@ -518,13 +518,16 @@ void rpc_sysfs_client_setup(struct rpc_clnt *clnt, struct net *net) { struct rpc_sysfs_client *rpc_client; + struct rpc_sysfs_xprt_switch *xswitch = + (struct rpc_sysfs_xprt_switch *)xprt_switch->xps_sysfs; + + if (!xswitch) + return; rpc_client = rpc_sysfs_client_alloc(rpc_sunrpc_client_kobj, net, clnt->cl_clid); if (rpc_client) { char name[] = "switch"; - struct rpc_sysfs_xprt_switch *xswitch = - (struct rpc_sysfs_xprt_switch *)xprt_switch->xps_sysfs; int ret; clnt->cl_sysfs = rpc_client; @@ -558,6 +561,8 @@ void rpc_sysfs_xprt_switch_setup(struct rpc_xprt_switch *xprt_switch, rpc_xprt_switch->xprt_switch = xprt_switch; rpc_xprt_switch->xprt = xprt; kobject_uevent(&rpc_xprt_switch->kobject, KOBJ_ADD); + } else { + xprt_switch->xps_sysfs = NULL; } } @@ -569,6 +574,9 @@ void rpc_sysfs_xprt_setup(struct rpc_xprt_switch *xprt_switch, struct rpc_sysfs_xprt_switch *switch_obj = (struct rpc_sysfs_xprt_switch *)xprt_switch->xps_sysfs; + if (!switch_obj) + return; + rpc_xprt = rpc_sysfs_xprt_alloc(&switch_obj->kobject, xprt, gfp_flags); if (rpc_xprt) { xprt->xprt_sysfs = rpc_xprt;