From: Maxime Ripard <maxime.ripard@xxxxxxxxxxx>
The named modes support has introduced a number of glitches that were in
part due to the fact that the parser will take any string as a named mode.
Since we shouldn't have a lot of options there (and they should be pretty
standard), let's introduce a whitelist of the available named modes so that
the kernel can differentiate between a poorly formed command line and a
named mode.
Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx>
---
drivers/gpu/drm/drm_modes.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index ea7e6c8c8318..988797d8080a 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -1677,6 +1677,22 @@ static int drm_mode_parse_cmdline_options(char *str, size_t len,
return 0;
}
+const char *drm_named_modes_whitelist[] = {
+ "NTSC",
+ "PAL",
+};
+
+static bool drm_named_mode_is_in_whitelist(const char *mode, unsigned int size)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(drm_named_modes_whitelist); i++)
+ if (!strncmp(mode, drm_named_modes_whitelist[i], size))
+ return true;
+
+ return false;
+}
+
/**
* drm_mode_parse_command_line_for_connector - parse command line modeline for connector
* @mode_option: optional per connector mode option
@@ -1794,6 +1810,10 @@ bool drm_mode_parse_command_line_for_connector(const char *mode_option,
if (named_mode) {
if (mode_end + 1 > DRM_DISPLAY_MODE_LEN)
return false;
+
+ if (!drm_named_mode_is_in_whitelist(name, mode_end))
+ return false;
+
strscpy(mode->name, name, mode_end + 1);
} else {
ret = drm_mode_parse_cmdline_res_mode(name, mode_end,
--
2.21.0
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