Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752062AbdLAKKv (ORCPT ); Fri, 1 Dec 2017 05:10:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52786 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751992AbdLAKKt (ORCPT ); Fri, 1 Dec 2017 05:10:49 -0500 From: wexu@redhat.com To: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: jasowang@redhat.com, mst@redhat.com, mjrosato@linux.vnet.ibm.com, wexu@redhat.com Subject: [PATCH 3/3] tap: free skb if flags error Date: Fri, 1 Dec 2017 05:10:38 -0500 Message-Id: <1512123038-15773-4-git-send-email-wexu@redhat.com> In-Reply-To: <1512123038-15773-1-git-send-email-wexu@redhat.com> References: <1512123038-15773-1-git-send-email-wexu@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Fri, 01 Dec 2017 10:10:49 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1459 Lines: 51 From: Wei Xu tap_recvmsg() supports accepting skb by msg_control after commit 3b4ba04acca8 ("tap: support receiving skb from msg_control"), the skb if presented should be freed within the function, otherwise it would be leaked. Signed-off-by: Wei Xu Reported-by: Matthew Rosato --- drivers/net/tap.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/net/tap.c b/drivers/net/tap.c index e9489b8..0a886fda 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -829,8 +829,11 @@ static ssize_t tap_do_read(struct tap_queue *q, DEFINE_WAIT(wait); ssize_t ret = 0; - if (!iov_iter_count(to)) + if (!iov_iter_count(to)) { + if (skb) + kfree_skb(skb); return 0; + } if (skb) goto put; @@ -1154,11 +1157,14 @@ static int tap_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len, int flags) { struct tap_queue *q = container_of(sock, struct tap_queue, sock); + struct sk_buff *skb = m->msg_control; int ret; - if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) + if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) { + if (skb) + kfree_skb(skb); return -EINVAL; - ret = tap_do_read(q, &m->msg_iter, flags & MSG_DONTWAIT, - m->msg_control); + } + ret = tap_do_read(q, &m->msg_iter, flags & MSG_DONTWAIT, skb); if (ret > total_len) { m->msg_flags |= MSG_TRUNC; ret = flags & MSG_TRUNC ? ret : total_len; -- 1.8.3.1