[PATCH 4.11 015/115] net/packet: fix missing net_device reference release

Greg Kroah-Hartman
2017-06-05T16:29:30Z

From: Douglas Caetano dos Santos <douglascs@taghos.com.br>

[ Upstream commit d19b183cdc1fa3d70d6abe2a4c369e748cd7ebb8 ]

When using a TX ring buffer, if an error occurs processing a control
message (e.g. invalid message), the net_device reference is not
released.

Fixes c14ac9451c348 ("sock: enable timestamping using control messages")
Signed-off-by: Douglas Caetano dos Santos <douglascs@taghos.com.br>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/packet/af_packet.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2614,13 +2614,6 @@ static int tpacket_snd(struct packet_soc
dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
}

- sockc.tsflags = po->sk.sk_tsflags;
- if (msg->msg_controllen) {
- err = sock_cmsg_send(&po->sk, msg, &sockc);
- if (unlikely(err))
- goto out;
- }
-
err = -ENXIO;
if (unlikely(dev == NULL))
goto out;
@@ -2628,6 +2621,13 @@ static int tpacket_snd(struct packet_soc
if (unlikely(!(dev->flags & IFF_UP)))
goto out_put;

+ sockc.tsflags = po->sk.sk_tsflags;
+ if (msg->msg_controllen) {
+ err = sock_cmsg_send(&po->sk, msg, &sockc);
+ if (unlikely(err))
+ goto out_put;
+ }
+
if (po->sk.sk_socket->type == SOCK_RAW)
reserve = dev->hard_header_len;
size_max = po->tx_ring.frame_size