From: Linus Walleij <linus.walleij@linaro.org>
To: Douglas Anderson <dianders@chromium.org>
Cc: dri-devel@lists.freedesktop.org,
Jani Nikula <jani.nikula@linux.intel.com>,
Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
Cong Yang <yangcong5@huaqin.corp-partner.google.com>,
Hsin-Yi Wang <hsinyi@google.com>,
Brian Norris <briannorris@chromium.org>,
Sam Ravnborg <sam@ravnborg.org>,
Neil Armstrong <neil.armstrong@linaro.org>,
Javier Martinez Canillas <javierm@redhat.com>,
Joel Selvaraj <jo@jsfamily.in>,
lvzhaoxiong@huaqin.corp-partner.google.com,
Daniel Vetter <daniel@ffwll.ch>,
David Airlie <airlied@gmail.com>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/9] drm/mipi-dsi: Fix theoretical int overflow in mipi_dsi_generic_write_seq()
Date: Thu, 2 May 2024 10:15:33 +0200 [thread overview]
Message-ID: <CACRpkdZQ5SHatac4uPUKd-ABu6Xd5PDYeKoFGvFQMssYOZW_mw@mail.gmail.com> (raw)
In-Reply-To: <20240501084109.v3.2.Iadb65b8add19ed3ae3ed6425011beb97e380a912@changeid>
On Wed, May 1, 2024 at 5:43 PM Douglas Anderson <dianders@chromium.org> wrote:
> The mipi_dsi_generic_write_seq() macro makes a call to
> mipi_dsi_generic_write() which returns a type ssize_t. The macro then
> stores it in an int and checks to see if it's negative. This could
> theoretically be a problem if "ssize_t" is larger than "int".
>
> To see the issue, imagine that "ssize_t" is 32-bits and "int" is
> 16-bits, you could see a problem if there was some code out there that
> looked like:
>
> mipi_dsi_generic_write_seq(dsi, <32768 bytes as arguments>);
>
> ...since we'd get back that 32768 bytes were transferred and 32768
> stored in a 16-bit int would look negative.
>
> Though there are no callsites where we'd actually hit this (even if
> "int" was only 16-bit), it's cleaner to make the types match so let's
> fix it.
>
> Fixes: a9015ce59320 ("drm/mipi-dsi: Add a mipi_dsi_dcs_write_seq() macro")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Yours,
Linus Walleij
next prev parent reply other threads:[~2024-05-02 8:15 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-01 15:41 [PATCH v3 0/9] drm/mipi-dsi: Reduce bloat and add funcs for cleaner init seqs Douglas Anderson
2024-05-01 15:41 ` [PATCH v3 1/9] drm/mipi-dsi: Fix theoretical int overflow in mipi_dsi_dcs_write_seq() Douglas Anderson
2024-05-02 7:26 ` Neil Armstrong
2024-05-02 8:15 ` Linus Walleij
2024-05-01 15:41 ` [PATCH v3 2/9] drm/mipi-dsi: Fix theoretical int overflow in mipi_dsi_generic_write_seq() Douglas Anderson
2024-05-02 7:26 ` Neil Armstrong
2024-05-02 8:15 ` Linus Walleij [this message]
2024-05-01 15:41 ` [PATCH v3 3/9] drm/mipi-dsi: mipi_dsi_*_write functions don't need to ratelimit prints Douglas Anderson
2024-05-02 7:27 ` Neil Armstrong
2024-05-02 8:16 ` Linus Walleij
2024-05-01 15:41 ` [PATCH v3 4/9] drm/mipi-dsi: Reduce driver bloat of mipi_dsi_*_write_seq() Douglas Anderson
2024-05-02 7:27 ` Neil Armstrong
2024-05-02 8:23 ` Linus Walleij
2024-05-02 16:59 ` Doug Anderson
2024-05-01 15:41 ` [PATCH v3 5/9] drm/mipi-dsi: Introduce mipi_dsi_*_write_seq_multi() Douglas Anderson
2024-05-02 7:28 ` Neil Armstrong
2024-05-06 6:22 ` Linus Walleij
2024-05-01 15:41 ` [PATCH v3 6/9] drm/panel: novatek-nt36672e: Switch to mipi_dsi_dcs_write_seq_multi() Douglas Anderson
2024-05-01 15:41 ` [PATCH v3 7/9] drm/panel: boe-tv101wum-nl6: Don't use a table for initting panels Douglas Anderson
2024-05-02 13:41 ` Linus Walleij
2024-05-02 16:40 ` Doug Anderson
2024-05-01 15:41 ` [PATCH v3 8/9] drm/panel: ili9882t: " Douglas Anderson
2024-05-06 6:19 ` Linus Walleij
2024-05-01 15:41 ` [PATCH v3 9/9] drm/panel: innolux-p079zca: " Douglas Anderson
2024-05-03 16:32 ` Doug Anderson
2024-05-06 6:45 ` Linus Walleij
2024-05-02 7:48 ` [PATCH v3 0/9] drm/mipi-dsi: Reduce bloat and add funcs for cleaner init seqs Neil Armstrong
2024-05-02 14:27 ` Doug Anderson
2024-05-02 16:05 ` neil.armstrong
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