From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-112.freemail.mail.aliyun.com (out30-112.freemail.mail.aliyun.com [115.124.30.112]) (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 670D679D2; Wed, 14 Aug 2024 13:11:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.112 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723641114; cv=none; b=YCqed1+xDfTL7k4pmi6XOOdSOSZHlyNcc9ihTseI4CvXUoeG+a5ZqJOVkq3K8XyIZlNq2NM5K3yHP4G8iojRjdWsqeDmhrKesli3vpmqoWxttvQXOIP3nB8lAM8+GmK5l6khsu1o9SRFaTSe9E9sHMC7Wj5R5pNhEdFxHh7GBh8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723641114; c=relaxed/simple; bh=sXKfyRW/bbUdXqvy1nBiAljMCPznDd1/ncx/XW4psWs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=i6nOcD2teHj1+ihX/APoRl7Y7A7pwJEr8sAjLZUJdbIBTCTVgEAEtKoWHBHf+w9ped4m8WPG+jdGITMj7immtnNTzonGu9fKD1yLNMF6jhtioWudcoAUT1Y52RkVRgzTd9Jx2sjzEoHkOUwJLvBVlWB7DA6QdoF0eodrCuu6Qa8= 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=BNP4VepI; arc=none smtp.client-ip=115.124.30.112 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="BNP4VepI" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1723641108; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=MJxfdv6IGm1spoOm9lhqUgWbinvAVNUc+DfFSJSCxcg=; b=BNP4VepILGSbZjPAet1Vikc+iNDHF1fJtt6wzGJH+V5HAFyAHKppoHS0dRrla4tzitaVcIpmDLpuhEgCmnu2W7JaXwM8qeOASTX4QVtHSXywiQDZXysWo85hZNmgf0p79lWPfdUsCdHpxAJFC3KdTItjg2NsVF0QRycpaZ80W2o= Received: from 192.168.50.173(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0WCt0vzC_1723641107) by smtp.aliyun-inc.com; Wed, 14 Aug 2024 21:11:48 +0800 Message-ID: Date: Wed, 14 Aug 2024 21:11:46 +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 , wenjia@linux.ibm.com, jaka@linux.ibm.com, tonylu@linux.alibaba.com, guwen@linux.alibaba.com, gbayer@linux.ibm.com Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, dust.li@linux.alibaba.com, linux-s390@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20240814104910.243859-1-aha310510@gmail.com> Content-Language: en-US From: "D. Wythe" In-Reply-To: <20240814104910.243859-1-aha310510@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/14/24 6:49 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 smc6_sock structure, initialize > .ipv6_pinfo_offset, and modify smc_sock structure. > > [ 278.629552][T28696] ================================================================== > [ 278.631367][T28696] BUG: KASAN: null-ptr-deref in txopt_get+0x102/0x430 > [ 278.632724][T28696] Read of size 4 at addr 0000000000000200 by task syz.0.2965/28696 > [ 278.634802][T28696] > [ 278.635236][T28696] CPU: 0 UID: 0 PID: 28696 Comm: syz.0.2965 Not tainted 6.11.0-rc2 #3 > [ 278.637458][T28696] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 > [ 278.639426][T28696] Call Trace: > [ 278.639833][T28696] > [ 278.640190][T28696] dump_stack_lvl+0x116/0x1b0 > [ 278.640844][T28696] ? txopt_get+0x102/0x430 > [ 278.641620][T28696] kasan_report+0xbd/0xf0 > [ 278.642440][T28696] ? txopt_get+0x102/0x430 > [ 278.643291][T28696] kasan_check_range+0xf4/0x1a0 > [ 278.644163][T28696] txopt_get+0x102/0x430 > [ 278.644940][T28696] ? __pfx_txopt_get+0x10/0x10 > [ 278.645877][T28696] ? selinux_netlbl_socket_setsockopt+0x1d0/0x420 > [ 278.646972][T28696] calipso_sock_getattr+0xc6/0x3e0 > [ 278.647630][T28696] calipso_sock_getattr+0x4b/0x80 > [ 278.648349][T28696] netlbl_sock_getattr+0x63/0xc0 > [ 278.649318][T28696] selinux_netlbl_socket_setsockopt+0x1db/0x420 > [ 278.650471][T28696] ? __pfx_selinux_netlbl_socket_setsockopt+0x10/0x10 > [ 278.652217][T28696] ? find_held_lock+0x2d/0x120 > [ 278.652231][T28696] selinux_socket_setsockopt+0x66/0x90 > [ 278.652247][T28696] security_socket_setsockopt+0x57/0xb0 > [ 278.652278][T28696] do_sock_setsockopt+0xf2/0x480 > [ 278.652289][T28696] ? __pfx_do_sock_setsockopt+0x10/0x10 > [ 278.652298][T28696] ? __fget_files+0x24b/0x4a0 > [ 278.652308][T28696] ? __fget_light+0x177/0x210 > [ 278.652316][T28696] __sys_setsockopt+0x1a6/0x270 > [ 278.652328][T28696] ? __pfx___sys_setsockopt+0x10/0x10 > [ 278.661787][T28696] ? xfd_validate_state+0x5d/0x180 > [ 278.662821][T28696] __x64_sys_setsockopt+0xbd/0x160 > [ 278.663719][T28696] ? lockdep_hardirqs_on+0x7c/0x110 > [ 278.664690][T28696] do_syscall_64+0xcb/0x250 > [ 278.665507][T28696] entry_SYSCALL_64_after_hwframe+0x77/0x7f > [ 278.666618][T28696] RIP: 0033:0x7fe87ed9712d > [ 278.667236][T28696] Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 > 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 > ff ff ff f7 d8 64 89 01 48 > [ 278.670801][T28696] RSP: 002b:00007fe87faa4fa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 > [ 278.671832][T28696] RAX: ffffffffffffffda RBX: 00007fe87ef35f80 RCX: 00007fe87ed9712d > [ 278.672806][T28696] RDX: 0000000000000036 RSI: 0000000000000029 RDI: 0000000000000003 > [ 278.674263][T28696] RBP: 00007fe87ee1bd8a R08: 0000000000000018 R09: 0000000000000000 > [ 278.675967][T28696] R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000000 > [ 278.677953][T28696] R13: 000000000000000b R14: 00007fe87ef35f80 R15: 00007fe87fa85000 > [ 278.679321][T28696] > [ 278.679917][T28696] ================================================================== > > Fixes: d25a92ccae6b ("net/smc: Introduce IPPROTO_SMC") > Signed-off-by: Jeongjun Park > --- > net/smc/smc.h | 5 ++++- > net/smc/smc_inet.c | 8 +++++++- > 2 files changed, 11 insertions(+), 2 deletions(-) > > diff --git a/net/smc/smc.h b/net/smc/smc.h > index 34b781e463c4..0d67a02a6ab1 100644 > --- a/net/smc/smc.h > +++ b/net/smc/smc.h > @@ -283,7 +283,10 @@ struct smc_connection { > }; > > struct smc_sock { /* smc sock container */ > - struct sock sk; > + union { > + struct sock sk; > + struct inet_sock inet; > + }; > struct socket *clcsock; /* internal tcp socket */ > void (*clcsk_state_change)(struct sock *sk); > /* original stat_change fct. */ > diff --git a/net/smc/smc_inet.c b/net/smc/smc_inet.c > index bece346dd8e9..9e5eff8f5226 100644 > --- a/net/smc/smc_inet.c > +++ b/net/smc/smc_inet.c > @@ -60,6 +60,11 @@ static struct inet_protosw smc_inet_protosw = { > }; > > #if IS_ENABLED(CONFIG_IPV6) > +struct smc6_sock { > + struct smc_sock smc; > + struct ipv6_pinfo inet6; > +}; > + > static struct proto smc_inet6_prot = { > .name = "INET6_SMC", > .owner = THIS_MODULE, > @@ -67,9 +72,10 @@ static struct proto smc_inet6_prot = { > .hash = smc_hash_sk, > .unhash = smc_unhash_sk, > .release_cb = smc_release_cb, > - .obj_size = sizeof(struct smc_sock), > + .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, inet6), > }; > > static const struct proto_ops smc_inet6_stream_ops = { > -- Hi Jeongjun, Thanks for you efforts, it makes sense to me now. But I still need some time to test it entirely before adding a r-by. I will appreciate for your patience. Thanks, D. Wythe