drm/i915/bios: fix a memory leak in generate_lfp_data_ptrs

[ Upstream commit 1382901 ]

When (size != 0 || ptrs->lvds_ entries != 3), the program tries to
free() the ptrs. However, the ptrs is not created by calling kzmalloc(),
but is obtained by pointer offset operation.
This may lead to memory leaks or undefined behavior.

Fix this by replacing the arguments of kfree() with ptrs_block.

Fixes: a87d0a8 ("drm/i915/bios: Generate LFP data table pointers if the VBT lacks them")
Signed-off-by: Xia Fukun <xiafukun@huawei.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221125063428.69486-1-xiafukun@huawei.com
(cherry picked from commit 7674cd0)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/gpu/drm/i915/display/intel_bios.c

@@ -414,7 +414,7 @@ static void *generate_lfp_data_ptrs(struct drm_i915_private *i915,
 		ptrs->lvds_entries++;
 
 	if (size != 0 || ptrs->lvds_entries != 3) {
-		kfree(ptrs);
+		kfree(ptrs_block);
 		return NULL;
 	}