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tap: double-free in error path in tap_open()

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[ 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@oracle.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Girish Moodalbail 2017-10-25 00:23:04 -07:00 committed by Greg Kroah-Hartman
parent 62de3fe46c
commit fbf92277e6
1 changed files with 9 additions and 9 deletions

18
drivers/net/macvtap.c

@ -559,6 +559,10 @@ static int macvtap_open(struct inode *inode, struct file *file)
&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 *inode, struct file *file)
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)