4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Girish Moodalbail <girish.moodalbail@xxxxxxxxxx>
[ Upstream commit 78e0ea6791d7baafb8a0ca82b1bd0c7b3453c919 ]
Double free of skb_array in tap module is causing kernel panic. When
tap_set_queue() fails we free skb_array right away by calling
skb_array_cleanup(). However, later on skb_array_cleanup() is called
again by tap_sock_destruct through sock_put(). This patch fixes that
issue.
Fixes: 362899b8725b35e3 (macvtap: switch to use skb array)
Signed-off-by: Girish Moodalbail <girish.moodalbail@xxxxxxxxxx>
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/macvtap.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -559,6 +559,10 @@ static int macvtap_open(struct inode *in
&macvtap_proto, 0);
if (!q)
goto err;
+ if (skb_array_init(&q->skb_array, dev->tx_queue_len, GFP_KERNEL)) {
+ sk_free(&q->sk);
+ goto err;
+ }
RCU_INIT_POINTER(q->sock.wq, &q->wq);
init_waitqueue_head(&q->wq.wait);
@@ -582,22 +586,18 @@ static int macvtap_open(struct inode *in
if ((dev->features & NETIF_F_HIGHDMA) && (dev->features & NETIF_F_SG))
sock_set_flag(&q->sk, SOCK_ZEROCOPY);
- err = -ENOMEM;
- if (skb_array_init(&q->skb_array, dev->tx_queue_len, GFP_KERNEL))
- goto err_array;
-
err = macvtap_set_queue(dev, file, q);
- if (err)
- goto err_queue;
+ if (err) {
+ /* macvtap_sock_destruct() will take care of freeing skb_array */
+ goto err_put;
+ }
dev_put(dev);
rtnl_unlock();
return err;
-err_queue:
- skb_array_cleanup(&q->skb_array);
-err_array:
+err_put:
sock_put(&q->sk);
err:
if (dev)