linux-kernel - Re: [3/7,media] dvb: don't use 'time

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 30 Aug 2017 22:25:01 +0200
From:   Arnd Bergmann <arnd@...db.de>
To:     Eugene Syromiatnikov <esyr@...hat.com>
Cc:     Linux Media Mailing List <linux-media@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        y2038 Mailman List <y2038@...ts.linaro.org>,
        Mauro Carvalho Chehab <mchehab@....samsung.com>,
        Linux API <linux-api@...r.kernel.org>,
        "moderated list:ARM/SAMSUNG EXYNOS ARM ARCHITECTURES" 
        <linux-samsung-soc@...r.kernel.org>,
        "Dmitry V. Levin" <ldv@...linux.org>,
        Gleb Fotengauer-Malinovskiy <glebfm@...linux.org>
Subject: Re: [3/7,media] dvb: don't use 'time_t' in event ioctl

>> diff --git a/include/uapi/linux/dvb/video.h b/include/uapi/linux/dvb/video.h
>> index d3d14a59d2d5..6c7f9298d7c2 100644
>> --- a/include/uapi/linux/dvb/video.h
>> +++ b/include/uapi/linux/dvb/video.h
>> @@ -135,7 +135,8 @@ struct video_event {
>>  #define VIDEO_EVENT_FRAME_RATE_CHANGED       2
>>  #define VIDEO_EVENT_DECODER_STOPPED  3
>>  #define VIDEO_EVENT_VSYNC            4
>> -     __kernel_time_t timestamp;
>> +     /* unused, make sure to use atomic time for y2038 if it ever gets used */
>> +     long timestamp;
>
> This change breaks x32 ABI (and possibly MIPS n32 ABI), as __kernel_time_t
> there is 64 bit already:
> https://sourceforge.net/p/strace/mailman/message/36015326/
>
> Note the change in structure size from 0x20 to 0x14 for VIDEO_GET_EVENT
> command in linux/x32/ioctls_inc0.h.

Are you sure it worked before the change? I don't see any handler in the kernel
for the x32 compat ioctl call here, only the compat_video_event handling, so
my guess is that the change unintentionally fixes x32.

         Arnd