From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2F96D11703 for ; Mon, 21 Aug 2023 19:55:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6EF6CC433C8; Mon, 21 Aug 2023 19:55:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1692647743; bh=/n9RbwhLuk1NdjMKMZDc+nv73wejL7euPUd27sv06iU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OleqEoFPlzX71RdMdd2JrMVATzXdCbfzlMV9euJNmKNdEUD4fHIO2cQY6uodBNBJF r7q3uxUKz456eXMTs2wUCC/+euGDP8H+WoWvmsRAiwX+1gt9eWX0XFXtiXjw6l/uFD B6bGyWbjjhQgWr4oio3xTNe8cJo0HiLb7uComLy8= 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 , Sasha Levin Subject: [PATCH 6.1 122/194] ipvs: fix racy memcpy in proc_do_sync_threshold Date: Mon, 21 Aug 2023 21:41:41 +0200 Message-ID: <20230821194128.077291235@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230821194122.695845670@linuxfoundation.org> References: <20230821194122.695845670@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Sishuai Gong [ Upstream commit 5310760af1d4fbea1452bfc77db5f9a680f7ae47 ] 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: Sasha Levin --- net/netfilter/ipvs/ip_vs_ctl.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index 03af6a2ffd567..17a1b731a76b1 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -1798,6 +1798,7 @@ static int proc_do_sync_threshold(struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { + struct netns_ipvs *ipvs = table->extra2; int *valp = table->data; int val[2]; int rc; @@ -1807,6 +1808,7 @@ proc_do_sync_threshold(struct ctl_table *table, int write, .mode = table->mode, }; + mutex_lock(&ipvs->sync_mutex); memcpy(val, valp, sizeof(val)); rc = proc_dointvec(&tmp, write, buffer, lenp, ppos); if (write) { @@ -1816,6 +1818,7 @@ proc_do_sync_threshold(struct ctl_table *table, int write, else memcpy(valp, val, sizeof(val)); } + mutex_unlock(&ipvs->sync_mutex); return rc; } @@ -4080,6 +4083,7 @@ static int __net_init ip_vs_control_net_init_sysctl(struct netns_ipvs *ipvs) 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; -- 2.40.1