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Subject: Re: [PATCH 01/11] media: tm6000: fix potential Spectre variant 1
To:     Dan Carpenter <dan.carpenter@oracle.com>,
        Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc:     Mauro Carvalho Chehab <mchehab@kernel.org>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
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From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Message-ID: <f342d8d6-b5e6-0cbf-d002-9561b79c90e4@embeddedor.com>
Date:   Tue, 15 May 2018 12:29:10 -0500
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On 05/15/2018 09:16 AM, Dan Carpenter wrote:
>>>
>>> I'm curious about how you finally resolved to handle these issues.
>>>
>>> I noticed Smatch is no longer reporting them.
>>
>> There was no direct fix for it, but maybe this patch has something
>> to do with the smatch error report cleanup:
>>
>> commit 3ad3b7a2ebaefae37a7eafed0779324987ca5e56
>> Author: Sami Tolvanen <samitolvanen@google.com>
>> Date:   Tue May 8 13:56:12 2018 -0400
>>
>>      media: v4l2-ioctl: replace IOCTL_INFO_STD with stub functions
>>      
>>      This change removes IOCTL_INFO_STD and adds stub functions where
>>      needed using the DEFINE_V4L_STUB_FUNC macro. This fixes indirect call
>>      mismatches with Control-Flow Integrity, caused by calling standard
>>      ioctls using a function pointer that doesn't match the function type.
>>      
>>      Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
>>      Signed-off-by: Hans Verkuil <hansverk@cisco.com>
>>      Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
>>

Thanks, Mauro.

> 
> Possibly...  There was an ancient bug in Smatch's function pointer
> handling.  I just pushed a fix for it now so the warning is there on
> linux-next.
> 

Dan,

These are all the Spectre media issues I see smatch is reporting in 
linux-next-20180515:

drivers/media/cec/cec-pin-error-inj.c:170 cec_pin_error_inj_parse_line() 
warn: potential spectre issue 'pin->error_inj_args'
drivers/media/dvb-core/dvb_ca_en50221.c:1479 dvb_ca_en50221_io_write() 
warn: potential spectre issue 'ca->slot_info' (local cap)
drivers/media/dvb-core/dvb_net.c:252 handle_one_ule_extension() warn: 
potential spectre issue 'p->ule_next_hdr'

I pulled the latest changes from the smatch repository and compiled it.

I'm running smatch v0.5.0-4459-g2f66d40 now. Is this the latest version?

I wonder if there is anything I might be missing.

Thanks
--
Gustavo