From 224e1eef0386a6448e51bc9f260978c3b4cfb533 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Wed, 30 Mar 2022 20:04:26 +0300 Subject: [PATCH] drm/edid: fix invalid EDID extension block filtering MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ 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 Signed-off-by: Jani Nikula Reviewed-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20220330170426.349248-1-jani.nikula@intel.com Signed-off-by: Sasha Levin --- 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 aeeab1b57aad..2dc6dd6230d7 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -1702,9 +1702,6 @@ 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) @@ -1721,6 +1718,9 @@ 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; }