From 68783aa6989756cda8e9e305292afbb9f4f5677c Mon Sep 17 00:00:00 2001 From: Wei Xu Date: Fri, 1 Dec 2017 05:10:38 -0500 Subject: [PATCH 10/13] tap: free skb if flags error MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Fabian Grünbichler --- 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 3570c7576993..4e04b6094f3c 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; @@ -1155,11 +1158,14 @@ 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; -- 2.14.2