From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-100.freemail.mail.aliyun.com (out30-100.freemail.mail.aliyun.com [115.124.30.100]) (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 1C5B5BA53; Thu, 15 Aug 2024 06:49:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.100 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723704564; cv=none; b=LIXQEYfO6Le4lmJng4YuiRR0BhX0NfIwT3KfQ5GaW8je37iqyUqX/s/TNGjPZrJ/p7/HPY7/pOQl5//hXcjzepZOSUnXIujLGruNR8lGbbMd2TOJGSqD0778BawyVdxwrJvHNuxr7pfcfuBTKDlgWjNQ5LvnYeWlD4CbkLPb4HQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723704564; c=relaxed/simple; bh=GBFDD5hO31UtxQ3fdpkMHOjwMKil/jfzWGsr7KvcUoI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rG53HEJN7qmp+c0Q6suFDwYmlslhHa7SK5CTnLN6adh/5pDA/A3q6SqUN0/tfDiZZCo3tgkQ8zw4NbVOwmkhC3VE4PujdF/unqA6wQRpyNR4Mp6E7EkLPHk1VgEt0htwiJiWuRk7mcCE62P9gbhDPjMVGipVb7fjchqNFgJ5cus= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=qNJcKvas; arc=none smtp.client-ip=115.124.30.100 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="qNJcKvas" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1723704558; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=FV7TrzVL+vp/dCsRizHWQY2sNChvjRjUcrbuhCkBO6k=; b=qNJcKvasXu/gKzyp3rROP8iVHJ1i1O6nZ4T4WpYuU5ld+PVRIcduwSqB1NP9BKzDAv4MmckVhELqVpYwSWvgMdOjbKD2olocOgql/T2SgOedq9hYqAexc5pgqP+4g8qz+KWd7QZ5rm0/IestnuV8FPpv18u1STZG41KBOfQYGPA= Received: from 30.221.149.192(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0WCvpwnH_1723704235) by smtp.aliyun-inc.com; Thu, 15 Aug 2024 14:43:56 +0800 Message-ID: <6bcd6097-13dd-44fd-aa67-39a3bcc69af2@linux.alibaba.com> Date: Thu, 15 Aug 2024 14:43:55 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net,v4] net/smc: prevent NULL pointer dereference in txopt_get To: Jeongjun Park Cc: wintera@linux.ibm.com, gbayer@linux.ibm.com, guwen@linux.alibaba.com, jaka@linux.ibm.com, tonylu@linux.alibaba.com, wenjia@linux.ibm.com, davem@davemloft.net, dust.li@linux.alibaba.com, edumazet@google.com, kuba@kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com References: <64c2d755-eb4b-42fa-befb-c4afd7e95f03@linux.ibm.com> <20240814150558.46178-1-aha310510@gmail.com> <9db86945-c889-4c0f-adcf-119a9cbeb0cc@linux.alibaba.com> Content-Language: en-US From: "D. Wythe" In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 8/15/24 11:15 AM, Jeongjun Park wrote: > 2024년 8월 15일 (목) 오전 11:51, D. Wythe 님이 작성: >> >> >> On 8/14/24 11:05 PM, Jeongjun Park wrote: >>> Alexandra Winter wrote: >>>> On 14.08.24 15:11, D. Wythe wrote: >>>>> struct smc_sock { /* smc sock container */ >>>>> - struct sock sk; >>>>> + union { >>>>> + struct sock sk; >>>>> + struct inet_sock inet; >>>>> + }; >>>> I don't see a path where this breaks, but it looks risky to me. >>>> Is an smc_sock always an inet_sock as well? Then can't you go with smc_sock->inet_sock->sk ? >>>> Or only in the IPPROTO SMC case, and in the AF_SMC case it is not an inet_sock? >> >> There is no smc_sock->inet_sock->sk before. And this part here was to >> make smc_sock also >> be an inet_sock. >> >> For IPPROTO_SMC, smc_sock should be an inet_sock, but it is not before. >> So, the initialization of certain fields >> in smc_sock(for example, clcsk) will overwrite modifications made to the >> inet_sock part in inet(6)_create. >> >> For AF_SMC, the only problem is that some space will be wasted. Since >> AF_SMC don't care the inet_sock part. >> However, make the use of sock by AF_SMC and IPPROTO_SMC separately for >> the sake of avoid wasting some space >> is a little bit extreme. >> > Okay. I think using inet_sock instead of sock is also a good idea, but I > understand for now. > > However, for some reason this patch status has become Changes Requested > , so we will split the patch into two and resend the v5 patch. > > Regards, > Jeongjun Park Why so hurry ? Are you rushing for some tasks ? Please be patient. The discussion is still ongoing, and you need to wait for everyone's opinions, at least you can wait a few days to see if there are any other opinions, even if you think your patch is correct. There is no need to send a new patch. If this patch is approved, the net maintainer will handle it, regardless of whether it is a change request or not. And your new patch, I don't want to go too far, as you are a newcomer, I appreciate your report and willingness to fix this issue. But it's wrong. If you want to split them, embedding inet_sock should be the first patch, which is a basic logical issue. Then, don't send patches so frequently, I'm very worried that you will immediately send out v6 after seeing it. Best wishes, D. Wythe >>> hmm... then how about changing it to something like this? >>> >>> @@ -283,7 +283,7 @@ struct smc_connection { >>> }; >>> >>> struct smc_sock { /* smc sock container */ >>> - struct sock sk; >>> + struct inet_sock inet; >>> struct socket *clcsock; /* internal tcp socket */ >>> void (*clcsk_state_change)(struct sock *sk); >> >> Don't. >> >>> /* original stat_change fct. */ >>> @@ -327,7 +327,7 @@ struct smc_sock { /* smc sock container */ >>> * */ >>> }; >>> >>> -#define smc_sk(ptr) container_of_const(ptr, struct smc_sock, sk) >>> +#define smc_sk(ptr) container_of_const(ptr, struct smc_sock, inet.sk) >>> >>> static inline void smc_init_saved_callbacks(struct smc_sock *smc) >>> { >>> >>> It is definitely not normal to make the first member of smc_sock as sock. >>> >>> Therefore, I think it would be appropriate to modify it to use inet_sock >>> as the first member like other protocols (sctp, dccp) and access sk in a >>> way like &smc->inet.sk. >>> >>> Although this fix would require more code changes, we tested the bug and >>> confirmed that it was not triggered and the functionality was working >>> normally. >>> >>> What do you think? >>> >>> Regards, >>> Jeongjun Park