From: Douglas Anderson <dianders@chromium.org>
To: dri-devel@lists.freedesktop.org
Cc: Linus Walleij <linus.walleij@linaro.org>,
lvzhaoxiong@huaqin.corp-partner.google.com,
Jani Nikula <jani.nikula@linux.intel.com>,
Hsin-Yi Wang <hsinyi@google.com>,
Javier Martinez Canillas <javierm@redhat.com>,
Neil Armstrong <neil.armstrong@linaro.org>,
Joel Selvaraj <jo@jsfamily.in>,
Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
Cong Yang <yangcong5@huaqin.corp-partner.google.com>,
Sam Ravnborg <sam@ravnborg.org>,
Douglas Anderson <dianders@chromium.org>,
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: [PATCH v2 2/8] drm/mipi-dsi: Fix theoretical int overflow in mipi_dsi_generic_write_seq()
Date: Fri, 26 Apr 2024 16:58:35 -0700 [thread overview]
Message-ID: <20240426165839.v2.2.Iadb65b8add19ed3ae3ed6425011beb97e380a912@changeid> (raw)
In-Reply-To: <20240426235857.3870424-1-dianders@chromium.org>
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>
---
Changes in v2:
- New
include/drm/drm_mipi_dsi.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index b3576be22bfa..5de2bd62448b 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -318,11 +318,11 @@ int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi,
do { \
static const u8 d[] = { seq }; \
struct device *dev = &dsi->dev; \
- int ret; \
+ ssize_t ret; \
ret = mipi_dsi_generic_write(dsi, d, ARRAY_SIZE(d)); \
if (ret < 0) { \
dev_err_ratelimited(dev, "transmit data failed: %d\n", \
- ret); \
+ (int)ret); \
return ret; \
} \
} while (0)
--
2.44.0.769.g3c40516874-goog
next prev parent reply other threads:[~2024-04-26 23:59 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-26 23:58 [PATCH v2 0/8] drm/mipi-dsi: Reduce bloat and add funcs for cleaner init seqs Douglas Anderson
2024-04-26 23:58 ` [PATCH v2 1/8] drm/mipi-dsi: Fix theoretical int overflow in mipi_dsi_dcs_write_seq() Douglas Anderson
2024-04-27 1:44 ` Dmitry Baryshkov
2024-04-27 6:22 ` Sam Ravnborg
2024-04-29 21:42 ` Doug Anderson
2024-04-26 23:58 ` Douglas Anderson [this message]
2024-04-26 23:58 ` [PATCH v2 3/8] drm/mipi-dsi: Reduce driver bloat of mipi_dsi_*_write_seq() Douglas Anderson
2024-04-27 2:05 ` Dmitry Baryshkov
2024-04-26 23:58 ` [PATCH v2 4/8] drm/mipi-dsi: Introduce mipi_dsi_*_write_seq_multi() Douglas Anderson
2024-04-27 6:32 ` Sam Ravnborg
2024-04-29 14:13 ` Doug Anderson
2024-04-29 9:38 ` Neil Armstrong
2024-04-29 14:26 ` Doug Anderson
2024-04-29 15:39 ` Jani Nikula
2024-05-01 15:49 ` Doug Anderson
2024-05-01 15:57 ` Dmitry Baryshkov
2024-05-06 6:21 ` Linus Walleij
2024-04-26 23:58 ` [PATCH v2 5/8] drm/mipi-dsi: mipi_dsi_*_write functions don't need to ratelimit prints Douglas Anderson
2024-04-26 23:58 ` [PATCH v2 6/8] drm/panel: novatek-nt36672e: Switch to mipi_dsi_dcs_write_seq_multi() Douglas Anderson
2024-04-26 23:58 ` [PATCH v2 7/8] drm/panel: boe-tv101wum-nl6: Don't use a table for initting commands Douglas Anderson
2024-04-26 23:58 ` [PATCH v2 8/8] drm/panel: boe-tv101wum-nl6: Convert hex to lowercase Douglas Anderson
2024-04-27 8:48 ` Dmitry Baryshkov
2024-04-29 9:20 ` [PATCH v2 0/8] drm/mipi-dsi: Reduce bloat and add funcs for cleaner init seqs Jani Nikula
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