2015-12-17 21:05:55

by David Miller

Subject: [PATCH 2/2] mkiss: Fix use after free in sixpack_close().

Need to do the unregister_device() after all references to the driver
private have been done.

Signed-off-by: David S. Miller <[email protected]>
---
drivers/net/hamradio/mkiss.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c
index 216bfd3..0b72b9d 100644
--- a/drivers/net/hamradio/mkiss.c
+++ b/drivers/net/hamradio/mkiss.c
@@ -798,13 +798,13 @@ static void mkiss_close(struct tty_struct *tty)
if (!atomic_dec_and_test(&ax->refcnt))
down(&ax->dead_sem);

- unregister_netdev(ax->dev);
-
/* Free all AX25 frame buffers. */
kfree(ax->rbuff);
kfree(ax->xbuff);

ax->tty = NULL;
+
+ unregister_netdev(ax->dev);
}

/* Perform I/O control on an active ax25 channel. */
--
2.4.1

2015-12-17 21:36:32

by Ralf Baechle

Subject: Re: [PATCH 2/2] mkiss: Fix use after free in sixpack_close().

On Thu, Dec 17, 2015 at 04:05:49PM -0500, David Miller wrote:

> Subject: [PATCH 2/2] mkiss: Fix use after free in sixpack_close().

Make that subject "... mkiss_close()."

Ralf

2015-12-18 21:03:50

by David Miller

Subject: Re: [PATCH 2/2] mkiss: Fix use after free in sixpack_close().

From: Ralf Baechle <[email protected]>
Date: Thu, 17 Dec 2015 22:35:31 +0100

> On Thu, Dec 17, 2015 at 04:05:49PM -0500, David Miller wrote:
>
>> Subject: [PATCH 2/2] mkiss: Fix use after free in sixpack_close().
>
> Make that subject "... mkiss_close()."

Durrr... indeed. Thanks for catching that.

Committed as follows:

====================
[PATCH] mkiss: Fix use after free in mkiss_close().

Need to do the unregister_device() after all references to the driver
private have been done.

Signed-off-by: David S. Miller <[email protected]>
---
drivers/net/hamradio/mkiss.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c
index 216bfd3..0b72b9d 100644
--- a/drivers/net/hamradio/mkiss.c
+++ b/drivers/net/hamradio/mkiss.c
@@ -798,13 +798,13 @@ static void mkiss_close(struct tty_struct *tty)
if (!atomic_dec_and_test(&ax->refcnt))
down(&ax->dead_sem);

- unregister_netdev(ax->dev);
-
/* Free all AX25 frame buffers. */
kfree(ax->rbuff);
kfree(ax->xbuff);

ax->tty = NULL;
+
+ unregister_netdev(ax->dev);
}

/* Perform I/O control on an active ax25 channel. */
--
2.4.1