From: David Miller <davem@davemloft.net>
To: changbinx.du@intel.com
Cc: oliver@neukum.org, linux-usb@vger.kernel.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net/cdc_ncm: fix null pointer panic at usbnet_link_change
Date: Tue, 29 Oct 2013 22:38:23 -0400 (EDT) [thread overview]
Message-ID: <20131029.223823.1852248673779937090.davem@davemloft.net> (raw)
In-Reply-To: <0C18FE92A7765D4EB9EE5D38D86A563A019F450F@SHSMSX103.ccr.corp.intel.com>
From: "Du, ChangbinX" <changbinx.du@intel.com>
Date: Tue, 29 Oct 2013 03:30:42 +0000
> In cdc_ncm_bind() function, it call cdc_ncm_bind_common() to setup usb.
> But cdc_ncm_bind_common() may meet error and cause usbnet_disconnect()
> be called which calls free_netdev(net). Thus usbnet structure(alloced
> with net_device structure) will be freed,too.
> So we cannot call usbnet_link_change() if cdc_ncm_bind_common() return
> error.
This is not the bug.
The problem is in cdc_ncm_bind_common().
It seems to leave dangling interface data pointers in some cases, and
then branches just to "error" so that they don't get cleared back out.
This bypasses the protection present in cdc_ncm_disconnect() meant to
avoid this problem.
next prev parent reply other threads:[~2013-10-30 2:38 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-29 3:30 [PATCH] net/cdc_ncm: fix null pointer panic at usbnet_link_change Du, ChangbinX
2013-10-29 8:41 ` Bjørn Mork
2013-10-31 3:06 ` Du, ChangbinX
[not found] ` <0C18FE92A7765D4EB9EE5D38D86A563A019F6384-0J0gbvR4kTggGBtAFL8yw7fspsVTdybXVpNB7YpNyf8@public.gmane.org>
2013-10-31 9:02 ` Bjørn Mork
2013-10-30 2:38 ` David Miller [this message]
2013-10-30 8:38 ` Bjørn Mork
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