Re: [PATCH 1/3] clk: imx: imx8qxp-lpcg: Reject duplicate clock indices

[Frank Li <Frank.li@oss.nxp.com>]

On Mon, Nov 02, 2026 at 01:48:49PM +0200, Abel Vesa wrote:
> imx_lpcg_parse_clks_from_dt() stores each clock it registers in
> clk_hws[bit_offset / 4], as every clock output of an LPCG owns a 4-bit
> field. Nothing checks that the clock-indices property names each field
> only once, though. If two entries fall into the same field, the second
> registration overwrites the first one in clk_hws[], leaking it, and if
> a later step fails, the error path computes the same index for both
> entries and unregisters the second clock twice.
>
> Reject a bit offset whose field already has a clock registered.
>
> Fixes: d5f1e6a2bb61 ("clk: imx: imx8qxp-lpcg: add parsing clocks from device tree")
> Cc: stable@vger.kernel.org
> Reported-by: Sashiko <sashiko-bot@kernel.org>
> Closes: https://sashiko.dev/#/bug/linux-07b8d98e-feb9-4c88-afb6-3b5e0b05dc00
> Signed-off-by: Abel Vesa <abel.vesa@oss.qualcomm.com>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  drivers/clk/imx/clk-imx8qxp-lpcg.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>
> diff --git a/drivers/clk/imx/clk-imx8qxp-lpcg.c b/drivers/clk/imx/clk-imx8qxp-lpcg.c
> index f0cf6cf91899..e57e7bc074a9 100644
> --- a/drivers/clk/imx/clk-imx8qxp-lpcg.c
> +++ b/drivers/clk/imx/clk-imx8qxp-lpcg.c
> @@ -251,6 +251,19 @@ static int imx_lpcg_parse_clks_from_dt(struct platform_device *pdev,
>  			goto unreg;
>  		}
>
> +		/*
> +		 * Each clock output owns a 4-bit field, so two bit offsets in
> +		 * the same field would describe the same clock. Registering it
> +		 * twice would leak the first registration, and the error path
> +		 * would then unregister the second one twice.
> +		 */
> +		if (clk_hws[idx]) {
> +			dev_warn(&pdev->dev, "duplicate bit offset of clock %d\n",
> +				 i);
> +			ret = -EINVAL;
> +			goto unreg;
> +		}
> +
>  		clk_hws[idx] = imx_clk_lpcg_scu_dev(&pdev->dev, output_names[i],
>  						    parent_names[i], 0, base,
>  						    bit_offset[i], false);
>
> --
> 2.54.0
>
>