ACK/cmnt: [X][E][CVE-2020-11608][SRU][PATCH 1/1] media: ov519: add missing endpoint sanity checks

[Kleber Souza]

On 16.04.20 11:33, Kleber Souza wrote:
> On 16.04.20 10:50, Po-Hsu Lin wrote:
>> From: Johan Hovold <johan at kernel.org>
>>
>> CVE-2020-11608
>>
>> Make sure to check that we have at least one endpoint before accessing
>> the endpoint array to avoid dereferencing a NULL-pointer on stream
>> start.
>>
>> Note that these sanity checks are not redundant as the driver is mixing
>> looking up altsettings by index and by number, which need not coincide.
>>
>> Fixes: 1876bb923c98 ("V4L/DVB (12079): gspca_ov519: add support for the ov511 bridge")
>> Fixes: b282d87332f5 ("V4L/DVB (12080): gspca_ov519: Fix ov518+ with OV7620AE (Trust spacecam 320)")
>> Cc: stable <stable at vger.kernel.org>     # 2.6.31
>> Cc: Hans de Goede <hdegoede at redhat.com>
>> Signed-off-by: Johan Hovold <johan at kernel.org>
>> Signed-off-by: Hans Verkuil <hverkuil-cisco at xs4all.nl>
>> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei at kernel.org>
>> (cherry picked from commit 998912346c0da53a6dbb71fab3a138586b596b30)
>> Signed-off-by: Po-Hsu Lin <po-hsu.lin at canonical.com>
> 
> LGTM.
> 
> Acked-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>
> 
> 
> The CVE matrix says this fix is needed for Xenial as well. Does it apply cleanly on X or
> does it need to be backported for it?

Never mind, I failed miserably to notice the tag for Xenial...

> 
>> ---
>>  drivers/media/usb/gspca/ov519.c | 10 ++++++++++
>>  1 file changed, 10 insertions(+)
>>
>> diff --git a/drivers/media/usb/gspca/ov519.c b/drivers/media/usb/gspca/ov519.c
>> index c7aafdb..9a49b50 100644
>> --- a/drivers/media/usb/gspca/ov519.c
>> +++ b/drivers/media/usb/gspca/ov519.c
>> @@ -3507,6 +3507,11 @@ static void ov511_mode_init_regs(struct sd *sd)
>>  		return;
>>  	}
>>  
>> +	if (alt->desc.bNumEndpoints < 1) {
>> +		sd->gspca_dev.usb_err = -ENODEV;
>> +		return;
>> +	}
>> +
>>  	packet_size = le16_to_cpu(alt->endpoint[0].desc.wMaxPacketSize);
>>  	reg_w(sd, R51x_FIFO_PSIZE, packet_size >> 5);
>>  
>> @@ -3632,6 +3637,11 @@ static void ov518_mode_init_regs(struct sd *sd)
>>  		return;
>>  	}
>>  
>> +	if (alt->desc.bNumEndpoints < 1) {
>> +		sd->gspca_dev.usb_err = -ENODEV;
>> +		return;
>> +	}
>> +
>>  	packet_size = le16_to_cpu(alt->endpoint[0].desc.wMaxPacketSize);
>>  	ov518_reg_w32(sd, R51x_FIFO_PSIZE, packet_size & ~7, 2);
>>  
>>
>