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 3E0B0C4332F for ; Sun, 18 Dec 2022 16:54:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232907AbiLRQyY (ORCPT ); Sun, 18 Dec 2022 11:54:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35766 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232934AbiLRQxc (ORCPT ); Sun, 18 Dec 2022 11:53:32 -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 DB5431B9C8; Sun, 18 Dec 2022 08:18:55 -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 297A660DD4; Sun, 18 Dec 2022 16:18:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2543C433F0; Sun, 18 Dec 2022 16:18:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671380334; bh=u9WqrnPVJ9jQElT9xcrWeDMun1mCi1qBsOZz8BvriCg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LohxOkLNQ6y+usW1XG5wzYA4qJ5EM3eEEUsFuc/ObLRaSHuzhke7V9XJYEqtIIIGc Q4Ypcs6YPhic3e+pX8sMO2PG9+rbBWm+a+w95W3jGqY//TxdCzocpZhguEWpCZxKYI KYrZN14p6Ywy/FW/L2fyPP1ACRYiU+5N4Vxl6SF4CC+pBOm/73WjcZRZmbAxjJjKFF Ho2V4FKO3nFsI/oREipYqtb65SIlVzWX49kW7aTOQSBrc4GxvsZm7zaDnt0I+1QL4a BkyIbiKck21bLLQZFBrNFmIHKfo/NuDaXao3+DAMWRA+ccysWRsXAq1yFaxd6DMFBL LhTfsN37s2Ovw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zhang Yuchen , Corey Minyard , Sasha Levin , openipmi-developer@lists.sourceforge.net Subject: [PATCH AUTOSEL 5.4 06/30] ipmi: fix memleak when unload ipmi driver Date: Sun, 18 Dec 2022 11:18:11 -0500 Message-Id: <20221218161836.933697-6-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221218161836.933697-1-sashal@kernel.org> References: <20221218161836.933697-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 736970312bbc..55f38058c0b4 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -3535,12 +3535,16 @@ 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