diff options
| author | Girish Moodalbail <girish.moodalbail@oracle.com> | 2017-10-25 10:23:04 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-10-26 11:57:39 +0300 |
| commit | 78e0ea6791d7baafb8a0ca82b1bd0c7b3453c919 (patch) | |
| tree | 6be52d342cd4ea32359a90ec7aabc96d9b08dd40 /drivers/net/tap.c | |
| parent | 5889e2c0e441d84060e66211ed5c4517ca591167 (diff) | |
| download | linux-78e0ea6791d7baafb8a0ca82b1bd0c7b3453c919.tar.xz | |
tap: double-free in error path in tap_open()
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>
Diffstat (limited to 'drivers/net/tap.c')
| -rw-r--r-- | drivers/net/tap.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/drivers/net/tap.c b/drivers/net/tap.c index 21b71ae947fd..98ee6cc2875d 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -517,6 +517,10 @@ static int tap_open(struct inode *inode, struct file *file) &tap_proto, 0); if (!q) goto err; + if (skb_array_init(&q->skb_array, tap->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); @@ -540,22 +544,18 @@ static int tap_open(struct inode *inode, struct file *file) if ((tap->dev->features & NETIF_F_HIGHDMA) && (tap->dev->features & NETIF_F_SG)) sock_set_flag(&q->sk, SOCK_ZEROCOPY); - err = -ENOMEM; - if (skb_array_init(&q->skb_array, tap->dev->tx_queue_len, GFP_KERNEL)) - goto err_array; - err = tap_set_queue(tap, file, q); - if (err) - goto err_queue; + if (err) { + /* tap_sock_destruct() will take care of freeing skb_array */ + goto err_put; + } dev_put(tap->dev); rtnl_unlock(); return err; -err_queue: - skb_array_cleanup(&q->skb_array); -err_array: +err_put: sock_put(&q->sk); err: if (tap) |