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Message-ID: <0a8e925f-4ad7-82ab-dd16-b2c0bf5aba48@redhat.com>
Date:   Wed, 19 Oct 2022 18:14:51 +0200
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Subject: Re: [PATCH] drm: tests: Fix a buffer overflow in format_helper_test
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To:     =?UTF-8?Q?Ma=c3=adra_Canal?= <mairacanal@riseup.net>,
        David Gow <davidgow@google.com>,
        =?UTF-8?B?Sm9zw6kgRXhww7NzaXRv?= <jose.exposito89@gmail.com>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Maxime Ripard <maxime@cerno.tech>,
        Naresh Kamboju <naresh.kamboju@linaro.org>
Cc:     dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        Linux Kernel Functional Testing <lkft@linaro.org>,
        Sam Ravnborg <sam@ravnborg.org>, kunit-dev@googlegroups.com
References: <20221019073239.3779180-1-davidgow@google.com>
 <6bb18060-158a-a2e7-3382-5d42813fe247@riseup.net>
From:   Javier Martinez Canillas <javierm@redhat.com>
In-Reply-To: <6bb18060-158a-a2e7-3382-5d42813fe247@riseup.net>
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On 10/19/22 13:36, Maíra Canal wrote:
> [cc Javier]
> 
> Hi David,
> 
> On 10/19/22 04:32, David Gow wrote:
>> The xrgb2101010 format conversion test (unlike for other formats) does
>> an endianness conversion on the results. However, it always converts
>> TEST_BUF_SIZE 32-bit integers, which results in reading from (and
>> writing to) more memory than in present in the result buffer. Instead,
>> use the buffer size, divided by sizeof(u32).
>>
>> The issue could be reproduced with KASAN:
>> ./tools/testing/kunit/kunit.py run --kunitconfig drivers/gpu/drm/tests \
>> 	--kconfig_add CONFIG_KASAN=y --kconfig_add CONFIG_KASAN_VMALLOC=y \
>> 	--kconfig_add CONFIG_KASAN_KUNIT_TEST=y \
>> 	drm_format_helper_test.*xrgb2101010
>>
>> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
>> Fixes: 453114319699 ("drm/format-helper: Add KUnit tests for drm_fb_xrgb8888_to_xrgb2101010()")
>> Signed-off-by: David Gow <davidgow@google.com>
> 
> Reviewed-by: Maíra Canal <mairacanal@riseup.net>
>

The fix makes sense to me as well,

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>

>> ---
>>
>> This is a fix for the issue reported here:
>> https://lore.kernel.org/dri-devel/CA+G9fYsuc9G+RO81E=vHMqxYStsmLURLdOB0NF26kJ1=K8pRZA@mail.gmail.com/
>>
>> Note that it may conflict with the KUNIT_EXPECT_MEMEQ() series here:
>> https://lore.kernel.org/linux-kselftest/20221018190541.189780-1-mairacanal@riseup.net/
> 
> I believe this patch will go to the drm-misc-fixes tree, so I can rebase
> the series (and address the format issues) as this patch hits mainline.
> 

Awesome. I assume you are pushing to drm-misc-fixes then?

Thanks a lot David and Maíra for taking care of this!

-- 
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat