From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Guenter Roeck <linux@roeck-us.net>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
Douglas Gilbert <dgilbert@interlog.com>
Subject: Re: [RFC PATCH] usb: typec: tcpm: Ignore unsupported/unknown alternate mode requests
Date: Fri, 2 Aug 2019 13:42:50 +0200 [thread overview]
Message-ID: <20190802114250.GA4721@kroah.com> (raw)
In-Reply-To: <1564029037-22929-1-git-send-email-linux@roeck-us.net>
On Wed, Jul 24, 2019 at 09:30:37PM -0700, Guenter Roeck wrote:
> TCPM may receive PD messages associated with unknown or unsupported
> alternate modes. If that happens, calls to typec_match_altmode()
> will return NULL. The tcpm code does not currently take this into
> account. This results in crashes.
>
> Unable to handle kernel NULL pointer dereference at virtual address 000001f0
> pgd = 41dad9a1
> [000001f0] *pgd=00000000
> Internal error: Oops: 5 [#1] THUMB2
> Modules linked in: tcpci tcpm
> CPU: 0 PID: 2338 Comm: kworker/u2:0 Not tainted 5.1.18-sama5-armv7-r2 #6
> Hardware name: Atmel SAMA5
> Workqueue: 2-0050 tcpm_pd_rx_handler [tcpm]
> PC is at typec_altmode_attention+0x0/0x14
> LR is at tcpm_pd_rx_handler+0xa3b/0xda0 [tcpm]
> ...
> [<c03fbee8>] (typec_altmode_attention) from [<bf8030fb>]
> (tcpm_pd_rx_handler+0xa3b/0xda0 [tcpm])
> [<bf8030fb>] (tcpm_pd_rx_handler [tcpm]) from [<c012082b>]
> (process_one_work+0x123/0x2a8)
> [<c012082b>] (process_one_work) from [<c0120a6d>]
> (worker_thread+0xbd/0x3b0)
> [<c0120a6d>] (worker_thread) from [<c012431f>] (kthread+0xcf/0xf4)
> [<c012431f>] (kthread) from [<c01010f9>] (ret_from_fork+0x11/0x38)
>
> Ignore PD messages if the asociated alternate mode is not supported.
>
> Reported-by: Douglas Gilbert <dgilbert@interlog.com>
> Cc: Douglas Gilbert <dgilbert@interlog.com>
> Fixes: e9576fe8e605c ("usb: typec: tcpm: Support for Alternate Modes")
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
> Taking a stab at the problem. I don't really know if this is the correct
> fix, or even if my understanding of the problem is correct, thus marking
> the patch as RFC.
Now that I think everyone agrees this is a "real" fix, can you resend it
in a format that I can apply it in, with the various acks added?
thanks,
greg k-h
next prev parent reply other threads:[~2019-08-02 11:42 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-25 4:30 [RFC PATCH] usb: typec: tcpm: Ignore unsupported/unknown alternate mode requests Guenter Roeck
2019-07-26 15:21 ` Douglas Gilbert
2019-07-29 14:04 ` Heikki Krogerus
2019-07-29 17:31 ` Guenter Roeck
2019-07-30 12:07 ` Heikki Krogerus
2019-07-30 12:17 ` Douglas Gilbert
2019-07-30 13:28 ` Guenter Roeck
2019-07-31 9:55 ` Heikki Krogerus
2019-08-01 16:07 ` Greg Kroah-Hartman
2019-08-02 8:01 ` Heikki Krogerus
2019-08-02 11:42 ` Greg Kroah-Hartman [this message]
2019-08-02 15:25 ` Douglas Gilbert
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