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 3E981C54E76 for ; Wed, 28 Dec 2022 16:53:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231839AbiL1Qxb (ORCPT ); Wed, 28 Dec 2022 11:53:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43244 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235154AbiL1Qwp (ORCPT ); Wed, 28 Dec 2022 11:52:45 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D52531C91E for ; Wed, 28 Dec 2022 08:47:31 -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 ams.source.kernel.org (Postfix) with ESMTPS id 74AA7B8188B for ; Wed, 28 Dec 2022 16:47:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C5C78C433EF; Wed, 28 Dec 2022 16:47:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672246049; bh=9k+WghrtSHhKkk8GrcM41+I21OA+exmk8bde1V9EZxo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GG+50PbhWC6AwhKOldvYucKKkANkFc5o02T7mZj1Qdgifu32yDgcfoVWvC+owaQ6Q XmjdaxIXFWJK7bddgKI81TRgdMgKmmauaLfExQYq+XgU/jnwUrf+dnPNfBWfLC2WGk VLCktFtuKAM8MdLgEurd92HC5bgw+aW6qxkbwDWE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhang Yuchen , Corey Minyard , Sasha Levin Subject: [PATCH 6.1 0972/1146] ipmi: fix memleak when unload ipmi driver Date: Wed, 28 Dec 2022 15:41:51 +0100 Message-Id: <20221228144356.744689263@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144330.180012208@linuxfoundation.org> References: <20221228144330.180012208@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zhang Yuchen [ Upstream commit 36992eb6b9b83f7f9cdc8e74fb5799d7b52e83e9 ] After the IPMI disconnect problem, the memory kept rising and we tried to unload the driver to free the memory. However, only part of the free memory is recovered after the driver is uninstalled. Using ebpf to hook free functions, we find that neither ipmi_user nor ipmi_smi_msg is free, only ipmi_recv_msg is free. We find that the deliver_smi_err_response call in clean_smi_msgs does the destroy processing on each message from the xmit_msg queue without checking the return value and free ipmi_smi_msg. deliver_smi_err_response is called only at this location. Adding the free handling has no effect. To verify, try using ebpf to trace the free function. $ bpftrace -e 'kretprobe:ipmi_alloc_recv_msg {printf("alloc rcv %p\n",retval);} kprobe:free_recv_msg {printf("free recv %p\n", arg0)} kretprobe:ipmi_alloc_smi_msg {printf("alloc smi %p\n", retval);} kprobe:free_smi_msg {printf("free smi %p\n",arg0)}' Signed-off-by: Zhang Yuchen Message-Id: <20221007092617.87597-4-zhangyuchen.lcr@bytedance.com> [Fixed the comment above handle_one_recv_msg().] Signed-off-by: Corey Minyard Signed-off-by: Sasha Levin --- drivers/char/ipmi/ipmi_msghandler.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 49a1707693c9..d5ee52be176d 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -3704,12 +3704,16 @@ static void deliver_smi_err_response(struct ipmi_smi *intf, struct ipmi_smi_msg *msg, unsigned char err) { + int rv; msg->rsp[0] = msg->data[0] | 4; msg->rsp[1] = msg->data[1]; msg->rsp[2] = err; msg->rsp_size = 3; - /* It's an error, so it will never requeue, no need to check return. */ - handle_one_recv_msg(intf, msg); + + /* This will never requeue, but it may ask us to free the message. */ + rv = handle_one_recv_msg(intf, msg); + if (rv == 0) + ipmi_free_smi_msg(msg); } static void cleanup_smi_msgs(struct ipmi_smi *intf) -- 2.35.1