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

[ Upstream commit 1382901f75a5a7dc8eac05059fd0c7816def4eae ]

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: a87d0a847607 ("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 7674cd0b7d28b952151c3df26bbfa7e07eb2b4ec)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index 459571e2cc575bb4fd1e8889008c534367867b86..2bfcfbfa52a4fd8a929ce74370959b124eeaa473 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/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;
        }