This is a note to let you know that I've just added the patch titled
tap: double-free in error path in tap_open()
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tap-double-free-in-error-path-in-tap_open.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Nov 15 17:24:03 CET 2017
From: Girish Moodalbail <girish.moodalbail@xxxxxxxxxx>
Date: Wed, 25 Oct 2017 00:23:04 -0700
Subject: tap: double-free in error path in tap_open()
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)
Patches currently in stable-queue which might be from girish.moodalbail@xxxxxxxxxx are
queue-4.9/tap-double-free-in-error-path-in-tap_open.patch