From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-110.freemail.mail.aliyun.com (out30-110.freemail.mail.aliyun.com [115.124.30.110]) (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 D23E9170A2B; Tue, 13 Aug 2024 11:37:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.110 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723549072; cv=none; b=VziQWm4gd8Dt+KkHBJhNx11DcskznT0yOJV4UsSTauDjaz1wJ+oNVNVRquoUmvb/pSIi01Sspe0l8V5vd4XkKmpUlPKiFp3WkkjjIjLAzHcRrHzqfSM143YkdjZ9DHDq//ADwAX5rKgXFUHbZLsY/VAN0T6am408hyBWtRcuFzI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723549072; c=relaxed/simple; bh=PJWrgO5y3JhQ6pVObk1LLEY6Ws3Bwk+wMwfRzlsIZFA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=fa7scv6IPuV1kBgJ6OlI8DRuKi5DUhm5kVwxkRohV/c4mtMaRKEPdrLsfBXc0pLtz1Ma21izxzcTnGdA7j3+VF9OZL4zG5H1TXXupCfOJfo7Io/cdFhOIU9d53iq212vz8kdMgmp4Kn08Zy5+NncbEq4Pwp9s85EsttyiMd0xwc= 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=Zca166UX; arc=none smtp.client-ip=115.124.30.110 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="Zca166UX" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1723549060; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=2I77YcUJn4wmoyRvCpJBoQDGsqzU26+ytOtN/lJqgpI=; b=Zca166UXp0gsLxPfMParM7J41ZaWOC1flL67+gzZ/V2W+yGvBXNsPBKbq5Yu6aQOvlggmCGXFkuiOKWCdRKS3O+Nf3kwjgz3cH9Lsda8Aq0JLIc8rOhO5TwXmRS2earhdcN93g20SEwBwUrWRixtnKizp/ng0Mtr7PTtL3kp7/E= Received: from 30.221.149.156(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0WCp.8vm_1723549058) by smtp.aliyun-inc.com; Tue, 13 Aug 2024 19:37:39 +0800 Message-ID: Date: Tue, 13 Aug 2024 19:37:38 +0800 Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net,v3] net/smc: prevent NULL pointer dereference in txopt_get To: Jeongjun Park , wenjia@linux.ibm.com, jaka@linux.ibm.com, gbayer@linux.ibm.com, tonylu@linux.alibaba.com, guwen@linux.alibaba.com Cc: davem@davemloft.net, dust.li@linux.alibaba.com, edumazet@google.com, pabeni@redhat.com, kuba@kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, netdev@vger.kernel.org, syzbot+f69bfae0a4eb29976e44@syzkaller.appspotmail.com References: <20240813100722.181250-1-aha310510@gmail.com> Content-Language: en-US From: "D. Wythe" In-Reply-To: <20240813100722.181250-1-aha310510@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/13/24 6:07 PM, Jeongjun Park wrote: > Since smc_inet6_prot does not initialize ipv6_pinfo_offset, inet6_create() > copies an incorrect address value, sk + 0 (offset), to inet_sk(sk)->pinet6. > > In addition, since inet_sk(sk)->pinet6 and smc_sk(sk)->clcsock practically > point to the same address, when smc_create_clcsk() stores the newly > created clcsock in smc_sk(sk)->clcsock, inet_sk(sk)->pinet6 is corrupted > into clcsock. This causes NULL pointer dereference and various other > memory corruptions. > > To solve this, we need to add a smc6_sock structure for ipv6_pinfo_offset > initialization and modify the smc_sock structure. > > Reported-by: syzbot+f69bfae0a4eb29976e44@syzkaller.appspotmail.com > Tested-by: syzbot+f69bfae0a4eb29976e44@syzkaller.appspotmail.com > Fixes: d25a92ccae6b ("net/smc: Introduce IPPROTO_SMC") > Signed-off-by: Jeongjun Park > --- > net/smc/smc.h | 19 ++++++++++--------- > net/smc/smc_inet.c | 24 +++++++++++++++--------- > 2 files changed, 25 insertions(+), 18 deletions(-) > > diff --git a/net/smc/smc.h b/net/smc/smc.h > index 34b781e463c4..f4d9338b5ed5 100644 > --- a/net/smc/smc.h > +++ b/net/smc/smc.h > @@ -284,15 +284,6 @@ struct smc_connection { > > struct smc_sock { /* smc sock container */ > struct sock sk; > - struct socket *clcsock; /* internal tcp socket */ > - void (*clcsk_state_change)(struct sock *sk); > - /* original stat_change fct. */ > - void (*clcsk_data_ready)(struct sock *sk); > - /* original data_ready fct. */ > - void (*clcsk_write_space)(struct sock *sk); > - /* original write_space fct. */ > - void (*clcsk_error_report)(struct sock *sk); > - /* original error_report fct. */ > struct smc_connection conn; /* smc connection */ > struct smc_sock *listen_smc; /* listen parent */ > struct work_struct connect_work; /* handle non-blocking connect*/ > @@ -325,6 +316,16 @@ struct smc_sock { /* smc sock container */ > /* protects clcsock of a listen > * socket > * */ > + struct socket *clcsock; /* internal tcp socket */ > + void (*clcsk_state_change)(struct sock *sk); > + /* original stat_change fct. */ > + void (*clcsk_data_ready)(struct sock *sk); > + /* original data_ready fct. */ > + void (*clcsk_write_space)(struct sock *sk); > + /* original write_space fct. */ > + void (*clcsk_error_report)(struct sock *sk); > + /* original error_report fct. */ > + > }; > > #define smc_sk(ptr) container_of_const(ptr, struct smc_sock, sk) > diff --git a/net/smc/smc_inet.c b/net/smc/smc_inet.c > index bece346dd8e9..25f34fd65e8d 100644 > --- a/net/smc/smc_inet.c > +++ b/net/smc/smc_inet.c > @@ -60,16 +60,22 @@ static struct inet_protosw smc_inet_protosw = { > }; > > #if IS_ENABLED(CONFIG_IPV6) > +struct smc6_sock { > + struct smc_sock smc; > + struct ipv6_pinfo np; > +}; I prefer to: struct ipv6_pinfo inet6; > + > static struct proto smc_inet6_prot = { > - .name = "INET6_SMC", > - .owner = THIS_MODULE, > - .init = smc_inet_init_sock, > - .hash = smc_hash_sk, > - .unhash = smc_unhash_sk, > - .release_cb = smc_release_cb, > - .obj_size = sizeof(struct smc_sock), > - .h.smc_hash = &smc_v6_hashinfo, > - .slab_flags = SLAB_TYPESAFE_BY_RCU, > + .name = "INET6_SMC", > + .owner = THIS_MODULE, > + .init = smc_inet_init_sock, > + .hash = smc_hash_sk, > + .unhash = smc_unhash_sk, > + .release_cb = smc_release_cb, > + .obj_size = sizeof(struct smc6_sock), > + .h.smc_hash = &smc_v6_hashinfo, > + .slab_flags = SLAB_TYPESAFE_BY_RCU, > + .ipv6_pinfo_offset = offsetof(struct smc6_sock, np), > }; > > static const struct proto_ops smc_inet6_stream_ops = { > --