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 5F9A8C433EF for ; Mon, 28 Feb 2022 17:44:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238534AbiB1Rms (ORCPT ); Mon, 28 Feb 2022 12:42:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238318AbiB1RjU (ORCPT ); Mon, 28 Feb 2022 12:39:20 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9CF7A8F98C; Mon, 28 Feb 2022 09:34:02 -0800 (PST) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 22902614CB; Mon, 28 Feb 2022 17:34:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 32A02C340E7; Mon, 28 Feb 2022 17:34:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1646069641; bh=qt3niuXE92R7t+jTdXk/hjGHrViVT+Y+HW2d36IGo6Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V2tLVqVGp2KiOHDUXklT4/yTzQxGnvohJBjjBUrOFyd5DApGydtwmKJY38wMU9g3v jfUHQmWySUT0cgxe2jaSFnFLZ5ZcyN3/Zefp0QAkWGUa0h4UfnenPq7WFILQUVcDhk 1eonPWDdT20CoEGhKMvCiC55+LrpL+lTM8T2Ozis= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Fabio M. De Francesco" , Karsten Graul , Jakub Kicinski , syzbot+4f322a6d84e991c38775@syzkaller.appspotmail.com, Tony Lu Subject: [PATCH 5.10 39/80] net/smc: Use a mutex for locking "struct smc_pnettable" Date: Mon, 28 Feb 2022 18:24:20 +0100 Message-Id: <20220228172316.191390981@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220228172311.789892158@linuxfoundation.org> References: <20220228172311.789892158@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: Fabio M. De Francesco commit 7ff57e98fb78ad94edafbdc7435f2d745e9e6bb5 upstream. smc_pnetid_by_table_ib() uses read_lock() and then it calls smc_pnet_apply_ib() which, in turn, calls mutex_lock(&smc_ib_devices.mutex). read_lock() disables preemption. Therefore, the code acquires a mutex while in atomic context and it leads to a SAC bug. Fix this bug by replacing the rwlock with a mutex. Reported-and-tested-by: syzbot+4f322a6d84e991c38775@syzkaller.appspotmail.com Fixes: 64e28b52c7a6 ("net/smc: add pnet table namespace support") Confirmed-by: Tony Lu Signed-off-by: Fabio M. De Francesco Acked-by: Karsten Graul Link: https://lore.kernel.org/r/20220223100252.22562-1-fmdefrancesco@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/smc/smc_pnet.c | 42 +++++++++++++++++++++--------------------- net/smc/smc_pnet.h | 2 +- 2 files changed, 22 insertions(+), 22 deletions(-) --- a/net/smc/smc_pnet.c +++ b/net/smc/smc_pnet.c @@ -112,7 +112,7 @@ static int smc_pnet_remove_by_pnetid(str pnettable = &sn->pnettable; /* remove table entry */ - write_lock(&pnettable->lock); + mutex_lock(&pnettable->lock); list_for_each_entry_safe(pnetelem, tmp_pe, &pnettable->pnetlist, list) { if (!pnet_name || @@ -130,7 +130,7 @@ static int smc_pnet_remove_by_pnetid(str rc = 0; } } - write_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); /* if this is not the initial namespace, stop here */ if (net != &init_net) @@ -191,7 +191,7 @@ static int smc_pnet_add_by_ndev(struct n sn = net_generic(net, smc_net_id); pnettable = &sn->pnettable; - write_lock(&pnettable->lock); + mutex_lock(&pnettable->lock); list_for_each_entry_safe(pnetelem, tmp_pe, &pnettable->pnetlist, list) { if (pnetelem->type == SMC_PNET_ETH && !pnetelem->ndev && !strncmp(pnetelem->eth_name, ndev->name, IFNAMSIZ)) { @@ -205,7 +205,7 @@ static int smc_pnet_add_by_ndev(struct n break; } } - write_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); return rc; } @@ -223,7 +223,7 @@ static int smc_pnet_remove_by_ndev(struc sn = net_generic(net, smc_net_id); pnettable = &sn->pnettable; - write_lock(&pnettable->lock); + mutex_lock(&pnettable->lock); list_for_each_entry_safe(pnetelem, tmp_pe, &pnettable->pnetlist, list) { if (pnetelem->type == SMC_PNET_ETH && pnetelem->ndev == ndev) { dev_put(pnetelem->ndev); @@ -236,7 +236,7 @@ static int smc_pnet_remove_by_ndev(struc break; } } - write_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); return rc; } @@ -371,7 +371,7 @@ static int smc_pnet_add_eth(struct smc_p rc = -EEXIST; new_netdev = true; - write_lock(&pnettable->lock); + mutex_lock(&pnettable->lock); list_for_each_entry(tmp_pe, &pnettable->pnetlist, list) { if (tmp_pe->type == SMC_PNET_ETH && !strncmp(tmp_pe->eth_name, eth_name, IFNAMSIZ)) { @@ -381,9 +381,9 @@ static int smc_pnet_add_eth(struct smc_p } if (new_netdev) { list_add_tail(&new_pe->list, &pnettable->pnetlist); - write_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); } else { - write_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); kfree(new_pe); goto out_put; } @@ -445,7 +445,7 @@ static int smc_pnet_add_ib(struct smc_pn new_pe->ib_port = ib_port; new_ibdev = true; - write_lock(&pnettable->lock); + mutex_lock(&pnettable->lock); list_for_each_entry(tmp_pe, &pnettable->pnetlist, list) { if (tmp_pe->type == SMC_PNET_IB && !strncmp(tmp_pe->ib_name, ib_name, IB_DEVICE_NAME_MAX)) { @@ -455,9 +455,9 @@ static int smc_pnet_add_ib(struct smc_pn } if (new_ibdev) { list_add_tail(&new_pe->list, &pnettable->pnetlist); - write_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); } else { - write_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); kfree(new_pe); } return (new_ibdev) ? 0 : -EEXIST; @@ -602,7 +602,7 @@ static int _smc_pnet_dump(struct net *ne pnettable = &sn->pnettable; /* dump pnettable entries */ - read_lock(&pnettable->lock); + mutex_lock(&pnettable->lock); list_for_each_entry(pnetelem, &pnettable->pnetlist, list) { if (pnetid && !smc_pnet_match(pnetelem->pnet_name, pnetid)) continue; @@ -617,7 +617,7 @@ static int _smc_pnet_dump(struct net *ne break; } } - read_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); return idx; } @@ -859,7 +859,7 @@ int smc_pnet_net_init(struct net *net) struct smc_pnetids_ndev *pnetids_ndev = &sn->pnetids_ndev; INIT_LIST_HEAD(&pnettable->pnetlist); - rwlock_init(&pnettable->lock); + mutex_init(&pnettable->lock); INIT_LIST_HEAD(&pnetids_ndev->list); rwlock_init(&pnetids_ndev->lock); @@ -939,7 +939,7 @@ static int smc_pnet_find_ndev_pnetid_by_ sn = net_generic(net, smc_net_id); pnettable = &sn->pnettable; - read_lock(&pnettable->lock); + mutex_lock(&pnettable->lock); list_for_each_entry(pnetelem, &pnettable->pnetlist, list) { if (pnetelem->type == SMC_PNET_ETH && ndev == pnetelem->ndev) { /* get pnetid of netdev device */ @@ -948,7 +948,7 @@ static int smc_pnet_find_ndev_pnetid_by_ break; } } - read_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); return rc; } @@ -1129,7 +1129,7 @@ int smc_pnetid_by_table_ib(struct smc_ib sn = net_generic(&init_net, smc_net_id); pnettable = &sn->pnettable; - read_lock(&pnettable->lock); + mutex_lock(&pnettable->lock); list_for_each_entry(tmp_pe, &pnettable->pnetlist, list) { if (tmp_pe->type == SMC_PNET_IB && !strncmp(tmp_pe->ib_name, ib_name, IB_DEVICE_NAME_MAX) && @@ -1139,7 +1139,7 @@ int smc_pnetid_by_table_ib(struct smc_ib break; } } - read_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); return rc; } @@ -1158,7 +1158,7 @@ int smc_pnetid_by_table_smcd(struct smcd sn = net_generic(&init_net, smc_net_id); pnettable = &sn->pnettable; - read_lock(&pnettable->lock); + mutex_lock(&pnettable->lock); list_for_each_entry(tmp_pe, &pnettable->pnetlist, list) { if (tmp_pe->type == SMC_PNET_IB && !strncmp(tmp_pe->ib_name, ib_name, IB_DEVICE_NAME_MAX)) { @@ -1167,7 +1167,7 @@ int smc_pnetid_by_table_smcd(struct smcd break; } } - read_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); return rc; } --- a/net/smc/smc_pnet.h +++ b/net/smc/smc_pnet.h @@ -29,7 +29,7 @@ struct smc_link_group; * @pnetlist: List of PNETIDs */ struct smc_pnettable { - rwlock_t lock; + struct mutex lock; struct list_head pnetlist; };