Hi Dinghao,
dinghao.liu@xxxxxxxxxx wrote on Tue, 26 Sep 2023 11:22:44 +0800:
> If of_clk_add_provider() fails in ca8210_register_ext_clock(),
> it calls clk_unregister() to release priv->clk and returns an
> error. However, the caller ca8210_probe() then calls ca8210_remove(),
> where priv->clk is freed again in ca8210_unregister_ext_clock(). In
> this case, a use-after-free may happen in the second time we call
> clk_unregister().
>
> Fix this by removing the first clk_unregister(). Also, priv->clk could
> be an error code on failure of clk_register_fixed_rate(). Use
> IS_ERR_OR_NULL to catch this case in ca8210_unregister_ext_clock().
>
> Fixes: ded845a781a5 ("ieee802154: Add CA8210 IEEE 802.15.4 device driver")
Missing Cc stable, this needs to be backported.
> Signed-off-by: Dinghao Liu <dinghao.liu@xxxxxxxxxx>
> ---
>
> Changelog:
>
> v2: -Remove the first clk_unregister() instead of nulling priv->clk.
> ---
> drivers/net/ieee802154/ca8210.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/net/ieee802154/ca8210.c b/drivers/net/ieee802154/ca8210.c
> index aebb19f1b3a4..b35c6f59bd1a 100644
> --- a/drivers/net/ieee802154/ca8210.c
> +++ b/drivers/net/ieee802154/ca8210.c
> @@ -2759,7 +2759,6 @@ static int ca8210_register_ext_clock(struct spi_device *spi)
> }
> ret = of_clk_add_provider(np, of_clk_src_simple_get, priv->clk);
> if (ret) {
> - clk_unregister(priv->clk);
> dev_crit(
> &spi->dev,
> "Failed to register external clock as clock provider\n"
I was hoping you would simplify this function a bit more.
> @@ -2780,7 +2779,7 @@ static void ca8210_unregister_ext_clock(struct spi_device *spi)
> {
> struct ca8210_priv *priv = spi_get_drvdata(spi);
>
> - if (!priv->clk)
> + if (IS_ERR_OR_NULL(priv->clk))
> return
>
> of_clk_del_provider(spi->dev.of_node);
Alex, Stefan, who handles wpan and wpan/next this release?
Thanks,
Miquèl
