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| author | Douglas Anderson <dianders@chromium.org> | 2024-05-14 20:20:51 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-08-03 09:53:45 +0300 |
| commit | 4e9d95a132d0b4a62e01a52c8ae3f43c8aed1eac (patch) | |
| tree | 49480f33232ff446239c28b3a60b5b72a9a874f0 /include | |
| parent | cd1885ae4cbf191332ae66f8a214e52fb226ba43 (diff) | |
| download | linux-4e9d95a132d0b4a62e01a52c8ae3f43c8aed1eac.tar.xz | |
drm/mipi-dsi: Fix theoretical int overflow in mipi_dsi_dcs_write_seq()
[ Upstream commit 0b03829fdece47beba9ecb7dbcbde4585ee3663e ]
The mipi_dsi_dcs_write_seq() macro makes a call to
mipi_dsi_dcs_write_buffer() 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_dcs_write_seq(dsi, cmd, <32767 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: 2a9e9daf7523 ("drm/mipi-dsi: Introduce mipi_dsi_dcs_write_seq macro")
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20240514102056.v5.1.I30fa4c8348ea316c886ef8a522a52fed617f930d@changeid
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240514102056.v5.1.I30fa4c8348ea316c886ef8a522a52fed617f930d@changeid
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/drm/drm_mipi_dsi.h | 24 |
1 files changed, 12 insertions, 12 deletions
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h index 3011d33eccbd..e0e2c17832e8 100644 --- a/include/drm/drm_mipi_dsi.h +++ b/include/drm/drm_mipi_dsi.h @@ -324,18 +324,18 @@ int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi, * @cmd: Command * @seq: buffer containing data to be transmitted */ -#define mipi_dsi_dcs_write_seq(dsi, cmd, seq...) \ - do { \ - static const u8 d[] = { cmd, seq }; \ - struct device *dev = &dsi->dev; \ - int ret; \ - ret = mipi_dsi_dcs_write_buffer(dsi, d, ARRAY_SIZE(d)); \ - if (ret < 0) { \ - dev_err_ratelimited( \ - dev, "sending command %#02x failed: %d\n", \ - cmd, ret); \ - return ret; \ - } \ +#define mipi_dsi_dcs_write_seq(dsi, cmd, seq...) \ + do { \ + static const u8 d[] = { cmd, seq }; \ + struct device *dev = &dsi->dev; \ + ssize_t ret; \ + ret = mipi_dsi_dcs_write_buffer(dsi, d, ARRAY_SIZE(d)); \ + if (ret < 0) { \ + dev_err_ratelimited( \ + dev, "sending command %#02x failed: %zd\n", \ + cmd, ret); \ + return ret; \ + } \ } while (0) /** |