On Thu, 18 Jun 2026, Ma Ke <[email protected]> wrote:
> i2c_adapter_lookup() acquires a reference on the i2c adapter through
> i2c_acpi_find_adapter_by_handle() but not releases it. Each
> invocation of this ACPI resource callback leaks one device reference,
> potentially leading to resource exhaustion over repeated driver
> load/unload cycles.
>
> Calling path: i2c_acpi_find_adapter_by_handle() -> bus_find_device()
> -> get_device.
>
> Found by code review.
>
> Signed-off-by: Ma Ke <[email protected]>
> Cc: [email protected]
> Fixes: 8cbf89db2941 ("drm/i915/dsi: Parse the I2C element from the VBT MIPI
> sequence block (v3)")
> ---
> Changes in v2:
> - Changed email to trigger CI, no code change.
Sorry, that won't do anything. Please just let us deal with it. :)
BR,
Jani.
> ---
> drivers/gpu/drm/i915/display/intel_dsi_vbt.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
> b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
> index fe12041e913c..2097c5d17cb7 100644
> --- a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
> +++ b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
> @@ -460,8 +460,10 @@ static int i2c_adapter_lookup(struct acpi_resource
> *ares, void *data)
> return 1;
>
> adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
> - if (adapter)
> + if (adapter) {
> intel_dsi->i2c_bus_num = adapter->nr;
> + put_device(&adapter->dev);
> + }
>
> return 1;
> }
--
Jani Nikula, Intel
