drm/dp/mst: fix a possible memory leak in fetch_monitor_name()

stable inclusion
from stable-v5.10.118
commit e5289affbacc0d88214111774adb02d771d1213d
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5L686

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e5289affbacc0d88214111774adb02d771d1213d

--------------------------------

commit 6e03b13 upstream.

drm_dp_mst_get_edid call kmemdup to create mst_edid. So mst_edid need to be
freed after use.

Signed-off-by: Hangyu Hua <[email protected]>
Reviewed-by: Lyude Paul <[email protected]>
Signed-off-by: Lyude Paul <[email protected]>
Cc: [email protected]
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Zheng Zengkai <[email protected]>
Acked-by: Xie XiuQi <[email protected]>

Author: HBh25Y

drivers/gpu/drm/drm_dp_mst_topology.c

@@ -4792,6 +4792,7 @@ static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
 
 	mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
 	drm_edid_get_monitor_name(mst_edid, name, namelen);
+	kfree(mst_edid);
 }
 
 /**