From mboxrd@z Thu Jan 1 00:00:00 1970 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 32ACCC433F5 for ; Mon, 18 Apr 2022 13:48:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244199AbiDRNu5 (ORCPT ); Mon, 18 Apr 2022 09:50:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244657AbiDRNaq (ORCPT ); Mon, 18 Apr 2022 09:30:46 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7E4D65AA; Mon, 18 Apr 2022 05:54:58 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 83DBFB80EC0; Mon, 18 Apr 2022 12:54:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CBFD9C385A1; Mon, 18 Apr 2022 12:54:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650286496; bh=0U1MH4AX840DC71MLBIHArHoLkvJ7+npJ2kTWvIyvH8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TgS4OmBTU6mIyvNEm1+j4uWg1zrNP6tg20egnQg1K/NUDGLiXVoR6yJISMQ8xNPpQ 1C1phSzjswkAojjs+yy2tZhFd1IinWisS9+DhOC2/ouLaX+f9rZnv0yfQ+nzdeLSU9 nfhOHioUfwoBsdwo529WTgEtL8yk4ESs5iTruh80= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiaomeng Tong , Trond Myklebust , Sasha Levin Subject: [PATCH 4.14 153/284] NFSv4/pNFS: Fix another issue with a list iterator pointing to the head Date: Mon, 18 Apr 2022 14:12:14 +0200 Message-Id: <20220418121216.033306116@linuxfoundation.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220418121210.689577360@linuxfoundation.org> References: <20220418121210.689577360@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Trond Myklebust [ Upstream commit 7c9d845f0612e5bcd23456a2ec43be8ac43458f1 ] In nfs4_callback_devicenotify(), if we don't find a matching entry for the deviceid, we're left with a pointer to 'struct nfs_server' that actually points to the list of super blocks associated with our struct nfs_client. Furthermore, even if we have a valid pointer, nothing pins the super block, and so the struct nfs_server could end up getting freed while we're using it. Since all we want is a pointer to the struct pnfs_layoutdriver_type, let's skip all the iteration over super blocks, and just use APIs to find the layout driver directly. Reported-by: Xiaomeng Tong Fixes: 1be5683b03a7 ("pnfs: CB_NOTIFY_DEVICEID") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/callback_proc.c | 27 +++++++++------------------ fs/nfs/pnfs.c | 11 +++++++++++ fs/nfs/pnfs.h | 2 ++ 3 files changed, 22 insertions(+), 18 deletions(-) diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c index 3998b432e1b9..825b3166605d 100644 --- a/fs/nfs/callback_proc.c +++ b/fs/nfs/callback_proc.c @@ -355,12 +355,11 @@ __be32 nfs4_callback_devicenotify(void *argp, void *resp, struct cb_process_state *cps) { struct cb_devicenotifyargs *args = argp; + const struct pnfs_layoutdriver_type *ld = NULL; uint32_t i; __be32 res = 0; - struct nfs_client *clp = cps->clp; - struct nfs_server *server = NULL; - if (!clp) { + if (!cps->clp) { res = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION); goto out; } @@ -368,23 +367,15 @@ __be32 nfs4_callback_devicenotify(void *argp, void *resp, for (i = 0; i < args->ndevs; i++) { struct cb_devicenotifyitem *dev = &args->devs[i]; - if (!server || - server->pnfs_curr_ld->id != dev->cbd_layout_type) { - rcu_read_lock(); - list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) - if (server->pnfs_curr_ld && - server->pnfs_curr_ld->id == dev->cbd_layout_type) { - rcu_read_unlock(); - goto found; - } - rcu_read_unlock(); - continue; + if (!ld || ld->id != dev->cbd_layout_type) { + pnfs_put_layoutdriver(ld); + ld = pnfs_find_layoutdriver(dev->cbd_layout_type); + if (!ld) + continue; } - - found: - nfs4_delete_deviceid(server->pnfs_curr_ld, clp, &dev->cbd_dev_id); + nfs4_delete_deviceid(ld, cps->clp, &dev->cbd_dev_id); } - + pnfs_put_layoutdriver(ld); out: kfree(args->devs); return res; diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index 619fc5c4c82c..18bbdaefd940 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -91,6 +91,17 @@ find_pnfs_driver(u32 id) return local; } +const struct pnfs_layoutdriver_type *pnfs_find_layoutdriver(u32 id) +{ + return find_pnfs_driver(id); +} + +void pnfs_put_layoutdriver(const struct pnfs_layoutdriver_type *ld) +{ + if (ld) + module_put(ld->owner); +} + void unset_pnfs_layoutdriver(struct nfs_server *nfss) { diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h index 965d657086c8..3504826c1ee7 100644 --- a/fs/nfs/pnfs.h +++ b/fs/nfs/pnfs.h @@ -219,6 +219,8 @@ struct pnfs_devicelist { extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *); extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *); +extern const struct pnfs_layoutdriver_type *pnfs_find_layoutdriver(u32 id); +extern void pnfs_put_layoutdriver(const struct pnfs_layoutdriver_type *ld); /* nfs4proc.c */ extern int nfs4_proc_getdeviceinfo(struct nfs_server *server, -- 2.34.1