On Fri, 25 Nov 2022, Xia Fukun <xiafukun@xxxxxxxxxx> wrote:
> 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.
Yeah probably worse things will happen than just leak.
>
> 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@xxxxxxxxxx>
Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_bios.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
> index 28bdb936cd1f..edbdb949b6ce 100644
> --- 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;
> }
--
Jani Nikula, Intel Open Source Graphics Center
