From patchwork Wed Oct 9 06:55:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Wythe" X-Patchwork-Id: 13827621 X-Patchwork-Delegate: kuba@kernel.org Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) (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 B542040849; Wed, 9 Oct 2024 06:55:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.132 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728456927; cv=none; b=d3DgnzRYdj8DSAq93xui7F/9HgBfrvttYqntTHygOPNnCeku5utwa/mO2CSb2ZT3ILgSIdwn+IaeBzIQwZ8fF74JWy9jOWyCko7fQG1zMSqWKIcJ95E8AtWeL4BCNSKGULKZJHMQmkvKJa5hVtFnvQA0p8auBRf9PUf21AJR4Bs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728456927; c=relaxed/simple; bh=Bd7iXoEa9UzFsOA5nZ4yG/NgHNPsFlJ16NHvU3fklNs=; h=From:To:Cc:Subject:Date:Message-Id; b=iRFZhr12wUppK5vLxIKchkvRI76MQfD8qqPzwYTjte0Gieuu1zbi23ODakqHyB6xja4pZGuwQXcbL4p5bQZ6mTVw9b5KFIbZOhJ3vP/LAQldGDNIF9EhNjVecmf+HWv2LAEtfPFvay3He24V8RDhXh4CkeuSQaWpX0U39tzj0ag= 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=NES5GyDT; arc=none smtp.client-ip=115.124.30.132 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="NES5GyDT" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1728456921; h=From:To:Subject:Date:Message-Id; bh=WQW8mgJmkTslYa2D7to3QWwlV3Xf9E2iC1P1rqJMGEM=; b=NES5GyDTxNjsfKNKAFfA+QKeQa/mosys9CX6o9nf32QACOQMWnxpz5xd3HqiMcQaYZRkP4maZvR7G0JP2+oZl26B6ZLW0lIpzO95ld8AG7j7fVj5NkNc3mV3k7H+sErC2Mt1nzbEjxzYIKRXLmEWTO2ayK8L/IFGBGfsYVrUHoY= Received: from j66a10360.sqa.eu95.tbsite.net(mailfrom:alibuda@linux.alibaba.com fp:SMTPD_---0WGhiQZL_1728456917) by smtp.aliyun-inc.com; Wed, 09 Oct 2024 14:55:20 +0800 From: "D. Wythe" To: kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@linux.ibm.com, wintera@linux.ibm.com, guwen@linux.alibaba.com Cc: kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org, tonylu@linux.alibaba.com, pabeni@redhat.com, edumazet@google.com Subject: [PATCH net] net/smc: fix lacks of icsk_syn_mss with IPPROTO_SMC Date: Wed, 9 Oct 2024 14:55:16 +0800 Message-Id: <1728456916-67035-1-git-send-email-alibuda@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: X-Patchwork-Delegate: kuba@kernel.org From: "D. Wythe" Eric report a panic on IPPROTO_SMC, and give the facts that when INET_PROTOSW_ICSK was set, icsk->icsk_sync_mss must be set too. Bug: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Mem abort info: ESR = 0x0000000086000005 EC = 0x21: IABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault user pgtable: 4k pages, 48-bit VAs, pgdp=00000001195d1000 [0000000000000000] pgd=0800000109c46003, p4d=0800000109c46003, pud=0000000000000000 Internal error: Oops: 0000000086000005 [#1] PREEMPT SMP Modules linked in: CPU: 1 UID: 0 PID: 8037 Comm: syz.3.265 Not tainted 6.11.0-rc7-syzkaller-g5f5673607153 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : 0x0 lr : cipso_v4_sock_setattr+0x2a8/0x3c0 net/ipv4/cipso_ipv4.c:1910 sp : ffff80009b887a90 x29: ffff80009b887aa0 x28: ffff80008db94050 x27: 0000000000000000 x26: 1fffe0001aa6f5b3 x25: dfff800000000000 x24: ffff0000db75da00 x23: 0000000000000000 x22: ffff0000d8b78518 x21: 0000000000000000 x20: ffff0000d537ad80 x19: ffff0000d8b78000 x18: 1fffe000366d79ee x17: ffff8000800614a8 x16: ffff800080569b84 x15: 0000000000000001 x14: 000000008b336894 x13: 00000000cd96feaa x12: 0000000000000003 x11: 0000000000040000 x10: 00000000000020a3 x9 : 1fffe0001b16f0f1 x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f x5 : 0000000000000040 x4 : 0000000000000001 x3 : 0000000000000000 x2 : 0000000000000002 x1 : 0000000000000000 x0 : ffff0000d8b78000 Call trace: 0x0 netlbl_sock_setattr+0x2e4/0x338 net/netlabel/netlabel_kapi.c:1000 smack_netlbl_add+0xa4/0x154 security/smack/smack_lsm.c:2593 smack_socket_post_create+0xa8/0x14c security/smack/smack_lsm.c:2973 security_socket_post_create+0x94/0xd4 security/security.c:4425 __sock_create+0x4c8/0x884 net/socket.c:1587 sock_create net/socket.c:1622 [inline] __sys_socket_create net/socket.c:1659 [inline] __sys_socket+0x134/0x340 net/socket.c:1706 __do_sys_socket net/socket.c:1720 [inline] __se_sys_socket net/socket.c:1718 [inline] __arm64_sys_socket+0x7c/0x94 net/socket.c:1718 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 Code: ???????? ???????? ???????? ???????? (????????) ---[ end trace 0000000000000000 ]--- This patch add a toy implementation that performs a simple return to prevent such panic. This is because MSS can be set in sock_create_kern or smc_setsockopt, similar to how it's done in AF_SMC. However, for AF_SMC, there is currently no way to synchronize MSS within __sys_connect_file. This toy implementation lays the groundwork for us to support such feature for IPPROTO_SMC in the future. Fixes: d25a92ccae6b ("net/smc: Introduce IPPROTO_SMC") Reported-by: Eric Dumazet Signed-off-by: D. Wythe Reviewed-by: Eric Dumazet Reviewed-by: Wenjia Zhang --- net/smc/smc_inet.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/net/smc/smc_inet.c b/net/smc/smc_inet.c index a5b20416..a944e7d 100644 --- a/net/smc/smc_inet.c +++ b/net/smc/smc_inet.c @@ -108,12 +108,23 @@ struct smc6_sock { }; #endif /* CONFIG_IPV6 */ +static unsigned int smc_sync_mss(struct sock *sk, u32 pmtu) +{ + /* No need pass it through to clcsock, mss can always be set by + * sock_create_kern or smc_setsockopt. + */ + return 0; +} + static int smc_inet_init_sock(struct sock *sk) { struct net *net = sock_net(sk); /* init common smc sock */ smc_sk_init(net, sk, IPPROTO_SMC); + + inet_csk(sk)->icsk_sync_mss = smc_sync_mss; + /* create clcsock */ return smc_create_clcsk(net, sk, sk->sk_family); }