4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Wei Xu <wexu@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
Reported-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxxxxxxx>
Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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)