From: Jani Nikula jani.nikula@intel.com
[ Upstream commit 3aefc722ff52076407203b6af9713de567993adf ]
The invalid EDID block filtering uses the number of valid EDID extensions instead of all EDID extensions for looping the extensions in the copy. This is fine, by coincidence, if all the invalid blocks are at the end of the EDID. However, it's completely broken if there are invalid extensions in the middle; the invalid blocks are included and valid blocks are excluded.
Fix it by modifying the base block after, not before, the copy.
Fixes: 14544d0937bf ("drm/edid: Only print the bad edid when aborting") Reported-by: Ville Syrjälä ville.syrjala@linux.intel.com Signed-off-by: Jani Nikula jani.nikula@intel.com Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20220330170426.349248-1-jani.n... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/drm_edid.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index ef26095719c5..28ea3d260bea 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -1709,9 +1709,6 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
connector_bad_edid(connector, edid, edid[0x7e] + 1);
- edid[EDID_LENGTH-1] += edid[0x7e] - valid_extensions; - edid[0x7e] = valid_extensions; - new = kmalloc_array(valid_extensions + 1, EDID_LENGTH, GFP_KERNEL); if (!new) @@ -1728,6 +1725,9 @@ struct edid *drm_do_get_edid(struct drm_connector *connector, base += EDID_LENGTH; }
+ new[EDID_LENGTH - 1] += new[0x7e] - valid_extensions; + new[0x7e] = valid_extensions; + kfree(edid); edid = new; }