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 05A26C433F5 for ; Fri, 25 Feb 2022 15:46:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242152AbiBYPrZ (ORCPT ); Fri, 25 Feb 2022 10:47:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242178AbiBYPrQ (ORCPT ); Fri, 25 Feb 2022 10:47:16 -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 539EC1FCD8 for ; Fri, 25 Feb 2022 07:46:44 -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 D22946192C for ; Fri, 25 Feb 2022 15:46:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD72FC340E7; Fri, 25 Feb 2022 15:46:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1645804003; bh=fs802bqjPDA0FQacyUaOPZqyW4ArTa5dOM/kFHPFD8A=; h=Subject:To:Cc:From:Date:From; b=xiNU9ZHvqeouFDHMFUYXavCMAORN9mXvDkPxvWlT7oIvsd+Rl/L0Q4j/oyb89eFkv Z0sNN8jYf2IlOWgggsoadI6RKfihnxkBAD5EogyZIbrYqVyUFa1Q3amlIgbq1A2hYW JolQn/yCAU7I+90Eo+ksxP+As+qtCKfL+iNqYCm4= Subject: FAILED: patch "[PATCH] net/smc: Use a mutex for locking "struct smc_pnettable"" failed to apply to 5.4-stable tree To: fmdefrancesco@gmail.com, kgraul@linux.ibm.com, kuba@kernel.org, tonylu@linux.alibaba.com Cc: From: Date: Fri, 25 Feb 2022 16:46:40 +0100 Message-ID: <164580400025315@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 7ff57e98fb78ad94edafbdc7435f2d745e9e6bb5 Mon Sep 17 00:00:00 2001 From: "Fabio M. De Francesco" Date: Wed, 23 Feb 2022 11:02:52 +0100 Subject: [PATCH] net/smc: Use a mutex for locking "struct smc_pnettable" 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 diff --git a/net/smc/smc_pnet.c b/net/smc/smc_pnet.c index 0599246c0376..29f0a559d884 100644 --- a/net/smc/smc_pnet.c +++ b/net/smc/smc_pnet.c @@ -113,7 +113,7 @@ static int smc_pnet_remove_by_pnetid(struct net *net, char *pnet_name) 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 || @@ -131,7 +131,7 @@ static int smc_pnet_remove_by_pnetid(struct net *net, char *pnet_name) rc = 0; } } - write_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); /* if this is not the initial namespace, stop here */ if (net != &init_net) @@ -192,7 +192,7 @@ static int smc_pnet_add_by_ndev(struct net_device *ndev) 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)) { @@ -206,7 +206,7 @@ static int smc_pnet_add_by_ndev(struct net_device *ndev) break; } } - write_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); return rc; } @@ -224,7 +224,7 @@ static int smc_pnet_remove_by_ndev(struct net_device *ndev) 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_track(pnetelem->ndev, &pnetelem->dev_tracker); @@ -237,7 +237,7 @@ static int smc_pnet_remove_by_ndev(struct net_device *ndev) break; } } - write_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); return rc; } @@ -370,7 +370,7 @@ static int smc_pnet_add_eth(struct smc_pnettable *pnettable, struct net *net, strncpy(new_pe->eth_name, eth_name, IFNAMSIZ); 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)) { @@ -385,9 +385,9 @@ static int smc_pnet_add_eth(struct smc_pnettable *pnettable, struct net *net, GFP_ATOMIC); } 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; } @@ -448,7 +448,7 @@ static int smc_pnet_add_ib(struct smc_pnettable *pnettable, char *ib_name, 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)) { @@ -458,9 +458,9 @@ static int smc_pnet_add_ib(struct smc_pnettable *pnettable, char *ib_name, } 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; @@ -605,7 +605,7 @@ static int _smc_pnet_dump(struct net *net, struct sk_buff *skb, u32 portid, 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; @@ -620,7 +620,7 @@ static int _smc_pnet_dump(struct net *net, struct sk_buff *skb, u32 portid, break; } } - read_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); return idx; } @@ -864,7 +864,7 @@ 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); @@ -944,7 +944,7 @@ static int smc_pnet_find_ndev_pnetid_by_table(struct net_device *ndev, 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 */ @@ -953,7 +953,7 @@ static int smc_pnet_find_ndev_pnetid_by_table(struct net_device *ndev, break; } } - read_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); return rc; } @@ -1156,7 +1156,7 @@ int smc_pnetid_by_table_ib(struct smc_ib_device *smcibdev, u8 ib_port) 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) && @@ -1166,7 +1166,7 @@ int smc_pnetid_by_table_ib(struct smc_ib_device *smcibdev, u8 ib_port) break; } } - read_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); return rc; } @@ -1185,7 +1185,7 @@ int smc_pnetid_by_table_smcd(struct smcd_dev *smcddev) 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)) { @@ -1194,7 +1194,7 @@ int smc_pnetid_by_table_smcd(struct smcd_dev *smcddev) break; } } - read_unlock(&pnettable->lock); + mutex_unlock(&pnettable->lock); return rc; } diff --git a/net/smc/smc_pnet.h b/net/smc/smc_pnet.h index 14039272f7e4..80a88eea4949 100644 --- 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; };