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 73EE0C4332F for ; Sun, 18 Dec 2022 16:46:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232753AbiLRQqh (ORCPT ); Sun, 18 Dec 2022 11:46:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51052 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231800AbiLRQpl (ORCPT ); Sun, 18 Dec 2022 11:45:41 -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 62FEC101FC; Sun, 18 Dec 2022 08:16:19 -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 D21C260DC9; Sun, 18 Dec 2022 16:16:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 87F48C433D2; Sun, 18 Dec 2022 16:16:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671380178; bh=FSsv1Qt4W1/uQvi48LAPtdUt7iKXNJabjclblcQa16o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q7LZ3hfK9tP5AktsxXuRjsFVQyC+wIJnlr1NTd/vEmhP6P/85mGmhfm1VkH2QKd7N La1hKOo3M9mPlyNyxD78hleNVCK+aA74fEpXrv3IzzDqnE6HtOIlTH2lcjkSoPOXyI zD/ITaygBfERyMKMsLOxQCNL72IfWAeWe5QcUbiZtCvsusGD2sQKInWKs7iBBiTRNq szuzTcezVPrZ8/2wJv/78lO4HhWzeNBMIAY0NC4aJlwB22zhWKTC+4MttQBeT0cTjD oDa2J19vX5wVb6FRbvcw3paBaDof/U931uiGWAwGowx4qL/pXt41zZN31NKav1zk0W J9B/Hktjk0Nhw== 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 5.10 06/39] ipmi: fix memleak when unload ipmi driver Date: Sun, 18 Dec 2022 11:15:26 -0500 Message-Id: <20221218161559.932604-6-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221218161559.932604-1-sashal@kernel.org> References: <20221218161559.932604-1-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 05e7339752ac..223b90247648 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -3540,12 +3540,16 @@ 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