From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peilin Ye Subject: [Linux-kernel-mentees] [PATCH net-next v2] ipvs: Fix uninit-value in do_ip_vs_set_ctl() Date: Tue, 11 Aug 2020 03:46:40 -0400 Message-ID: <20200811074640.841693-1-yepeilin.cs@gmail.com> References: <20200810220703.796718-1-yepeilin.cs@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=OOMSJE9xSBil9mXDx2Lia4KUqWqXBp/e2t+xm7m3Qh8=; b=F1f7ZE4KDjPF6dImWkq/5Gb5Ibw/zsrD+Y+bAFrUMb2y8iUJult1fm9hB0McdzouIP JdDgEL1T2JKzUfHwWYdBwmkOObOmECVPSE43vBjnO8kfMo4FuMKCwhbmdiKeIPv5iz7L IE25z3GCJwOCUWTeQCgIZMZ8PIMkHN+IFDgY8wMNCbsC3ngJJuI7/lB+STIlvY2ysxqF ldKh+gEuY1fZUGum5vnuiVAGZ4fX/Dcx3RTT3RcYeK3t/7XuKa7ZhV+D86LSpYOVn+GG d4Gr2ojxTkHSGSiIKscJVFKq+vyJBGOqJiFz5iMLUNPcjV+SCQjFLjVaYbqOvQ2CLPI0 j6gg== In-Reply-To: <20200810220703.796718-1-yepeilin.cs@gmail.com> Sender: lvs-devel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Wensong Zhang , Simon Horman , Julian Anastasov Cc: Peilin Ye , Cong Wang , Pablo Neira Ayuso , Jozsef Kadlecsik , Florian Westphal , "David S. Miller" , Jakub Kicinski , Greg Kroah-Hartman , netdev@vger.kernel.org, lvs-devel@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, linux-kernel-mentees@lists.linuxfoundation.org, syzkaller-bugs@googlegroups.com, linux-kernel@vger.kernel.org do_ip_vs_set_ctl() is referencing uninitialized stack value when `len` is zero. Fix it. Reported-by: syzbot+23b5f9e7caf61d9a3898@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=46ebfb92a8a812621a001ef04d90dfa459520fe2 Suggested-by: Julian Anastasov Signed-off-by: Peilin Ye --- Changes in v2: - Target net-next tree. (Suggested by Julian Anastasov ) - Reject all `len == 0` requests except `IP_VS_SO_SET_FLUSH`, instead of initializing `arg`. (Suggested by Cong Wang , Julian Anastasov ) net/netfilter/ipvs/ip_vs_ctl.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index 412656c34f20..beeafa42aad7 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -2471,6 +2471,10 @@ do_ip_vs_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) /* Set timeout values for (tcp tcpfin udp) */ ret = ip_vs_set_timeout(ipvs, (struct ip_vs_timeout_user *)arg); goto out_unlock; + } else if (!len) { + /* No more commands with len == 0 below */ + ret = -EINVAL; + goto out_unlock; } usvc_compat = (struct ip_vs_service_user *)arg; @@ -2547,9 +2551,6 @@ do_ip_vs_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) break; case IP_VS_SO_SET_DELDEST: ret = ip_vs_del_dest(svc, &udest); - break; - default: - ret = -EINVAL; } out_unlock: -- 2.25.1