From 3aefc722ff52076407203b6af9713de567993adf Mon Sep 17 00:00:00 2001
From: Jani Nikula <jani.nikula@intel.com>
Date: Wed, 30 Mar 2022 20:04:26 +0300
Subject: [PATCH] drm/edid: fix invalid EDID extension block filtering
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Git-commit: 3aefc722ff52076407203b6af9713de567993adf
Patch-mainline: v5.19-rc1
References: git-fixes
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 Syrj채l채 <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrj채l채 <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220330170426.349248-1-jani.nikula@intel.com
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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 359c52e5318a..18e1b88cd894 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -2031,9 +2031,6 @@ 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)
@@ -2050,6 +2047,9 @@ 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;
}
--
2.35.3