4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Wei Xu <wexu@xxxxxxxxxx>
[ Upstream commit 61d78537843e676e7f56ac6db333db0c0529b892 ]
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 <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/tap.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
--- a/drivers/net/tap.c
+++ b/drivers/net/tap.c
@@ -829,8 +829,11 @@ static ssize_t tap_do_read(struct tap_qu
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 *so
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;