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 C9BF0C83F1B for ; Mon, 28 Aug 2023 10:29:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231295AbjH1K2k (ORCPT ); Mon, 28 Aug 2023 06:28:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231408AbjH1K21 (ORCPT ); Mon, 28 Aug 2023 06:28:27 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6AE0E136 for ; Mon, 28 Aug 2023 03:28:20 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id F264263BC6 for ; Mon, 28 Aug 2023 10:28:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13F94C433C7; Mon, 28 Aug 2023 10:28:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693218499; bh=TcA3HtzEvy/Zs9AGzsS6fGgJUy9zoIlETYhu0bLsgmc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yODpLQy4wKBT9QVgPN/2sJi6+54UjYwyZx2iZetf6M11IqQCAzSl4s4/T0RZjxE7O EMx9DwMTsX/k9XPx/53EgknDPbEgPUjqBABjGR6t6ZzN0/DnO9JpLrH2Wcjz34n9AR Z/gbKsWhS8BLJ2BLQZo5dPJbjRqnhKj5qPz9KT4g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sishuai Gong , Simon Horman , Julian Anastasov , Florian Westphal Subject: [PATCH 4.19 109/129] ipvs: fix racy memcpy in proc_do_sync_threshold Date: Mon, 28 Aug 2023 12:13:23 +0200 Message-ID: <20230828101157.232908332@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101153.030066927@linuxfoundation.org> References: <20230828101153.030066927@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sishuai Gong commit 5310760af1d4fbea1452bfc77db5f9a680f7ae47 upstream. When two threads run proc_do_sync_threshold() in parallel, data races could happen between the two memcpy(): Thread-1 Thread-2 memcpy(val, valp, sizeof(val)); memcpy(valp, val, sizeof(val)); This race might mess up the (struct ctl_table *) table->data, so we add a mutex lock to serialize them. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Link: https://lore.kernel.org/netdev/B6988E90-0A1E-4B85-BF26-2DAF6D482433@gmail.com/ Signed-off-by: Sishuai Gong Acked-by: Simon Horman Acked-by: Julian Anastasov Signed-off-by: Florian Westphal Signed-off-by: Greg Kroah-Hartman --- net/netfilter/ipvs/ip_vs_ctl.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -1690,6 +1690,7 @@ static int proc_do_sync_threshold(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { + struct netns_ipvs *ipvs = table->extra2; int *valp = table->data; int val[2]; int rc; @@ -1699,6 +1700,7 @@ proc_do_sync_threshold(struct ctl_table .mode = table->mode, }; + mutex_lock(&ipvs->sync_mutex); memcpy(val, valp, sizeof(val)); rc = proc_dointvec(&tmp, write, buffer, lenp, ppos); if (write) { @@ -1708,6 +1710,7 @@ proc_do_sync_threshold(struct ctl_table else memcpy(valp, val, sizeof(val)); } + mutex_unlock(&ipvs->sync_mutex); return rc; } @@ -3944,6 +3947,7 @@ static int __net_init ip_vs_control_net_ ipvs->sysctl_sync_threshold[0] = DEFAULT_SYNC_THRESHOLD; ipvs->sysctl_sync_threshold[1] = DEFAULT_SYNC_PERIOD; tbl[idx].data = &ipvs->sysctl_sync_threshold; + tbl[idx].extra2 = ipvs; tbl[idx++].maxlen = sizeof(ipvs->sysctl_sync_threshold); ipvs->sysctl_sync_refresh_period = DEFAULT_SYNC_REFRESH_PERIOD; tbl[idx++].data = &ipvs->sysctl_sync_refresh_period;