Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756151AbdLOJyk (ORCPT ); Fri, 15 Dec 2017 04:54:40 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:36640 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755854AbdLOJyf (ORCPT ); Fri, 15 Dec 2017 04:54:35 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wei Xu , Matthew Rosato , "Michael S. Tsirkin" , "David S. Miller" Subject: [PATCH 4.14 27/52] tun: free skb in early errors Date: Fri, 15 Dec 2017 10:52:04 +0100 Message-Id: <20171215092309.961482795@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171215092308.500651185@linuxfoundation.org> References: <20171215092308.500651185@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2242 Lines: 85 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wei Xu [ Upstream commit c33ee15b3820a03cf8229ba9415084197b827f8c ] tun_recvmsg() supports accepting skb by msg_control after commit ac77cfd4258f ("tun: support receiving skb through msg_control"), the skb if presented should be freed no matter how far it can go along, otherwise it would be leaked. This patch fixes several missed cases. Signed-off-by: Wei Xu Reported-by: Matthew Rosato Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/tun.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1734,8 +1734,11 @@ static ssize_t tun_do_read(struct tun_st tun_debug(KERN_INFO, tun, "tun_do_read\n"); - if (!iov_iter_count(to)) + if (!iov_iter_count(to)) { + if (skb) + kfree_skb(skb); return 0; + } if (!skb) { /* Read frames from ring */ @@ -1851,22 +1854,24 @@ static int tun_recvmsg(struct socket *so { struct tun_file *tfile = container_of(sock, struct tun_file, socket); struct tun_struct *tun = __tun_get(tfile); + struct sk_buff *skb = m->msg_control; int ret; - if (!tun) - return -EBADFD; + if (!tun) { + ret = -EBADFD; + goto out_free_skb; + } if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) { ret = -EINVAL; - goto out; + goto out_put_tun; } if (flags & MSG_ERRQUEUE) { ret = sock_recv_errqueue(sock->sk, m, total_len, SOL_PACKET, TUN_TX_TIMESTAMP); goto out; } - ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT, - m->msg_control); + ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT, skb); if (ret > (ssize_t)total_len) { m->msg_flags |= MSG_TRUNC; ret = flags & MSG_TRUNC ? ret : total_len; @@ -1874,6 +1879,13 @@ static int tun_recvmsg(struct socket *so out: tun_put(tun); return ret; + +out_put_tun: + tun_put(tun); +out_free_skb: + if (skb) + kfree_skb(skb); + return ret; } static int tun_peek_len(struct socket *sock)