4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Wei Xu wexu@redhat.com
[ 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 wexu@redhat.com Reported-by: Matthew Rosato mjrosato@linux.vnet.ibm.com Acked-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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)