[PATCH] ALSA: hda: cs35l41: fix double free in cs35l41_hda_probe()

[Andy Shevchenko]

On Saturday, January 8, 2022, <trix at redhat.com> wrote:

> From: Tom Rix <trix at redhat.com>
>
> Clang static analysis reports this problem
> cs35l41_hda.c:501:2: warning: Attempt to free released memory
>         kfree(acpi_hw_cfg);
>         ^~~~~~~~~~~~~~~~~~
>
> This second free happens in the function's error handler which
> is normally ok but acpi_hw_cfg is freed in the non error case
> when it is still possible to have an error.
>
> Consolidate the frees.
>
> Fixes: 7b2f3eb492da ("ALSA: hda: cs35l41: Add support for CS35L41 in HDA
> systems")
> Signed-off-by: Tom Rix <trix at redhat.com>
> ---
>  sound/pci/hda/cs35l41_hda.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/sound/pci/hda/cs35l41_hda.c b/sound/pci/hda/cs35l41_hda.c
> index aa5bb6977792c..265ace98965f5 100644
> --- a/sound/pci/hda/cs35l41_hda.c
> +++ b/sound/pci/hda/cs35l41_hda.c
> @@ -476,7 +476,6 @@ int cs35l41_hda_probe(struct device *dev, const char
> *device_name, int id, int i
>         ret = cs35l41_hda_apply_properties(cs35l41, acpi_hw_cfg);
>         if (ret)
>                 goto err;
> -       kfree(acpi_hw_cfg);
>
>         if (cs35l41->reg_seq->probe) {
>                 ret = regmap_register_patch(cs35l41->regmap,
> cs35l41->reg_seq->probe,
> @@ -495,13 +494,14 @@ int cs35l41_hda_probe(struct device *dev, const char
> *device_name, int id, int i
>
>         dev_info(cs35l41->dev, "Cirrus Logic CS35L41 (%x), Revision:
> %02X\n", regid, reg_revid);
>
> -       return 0;
> -
>  err:
>         kfree(acpi_hw_cfg);
> -       if (!cs35l41->vspk_always_on)
> -               gpiod_set_value_cansleep(cs35l41->reset_gpio, 0);
> -       gpiod_put(cs35l41->reset_gpio);
> +
> +       if (unlikely(ret)) {


This is double weird. First of all, wtf unlikely is here? Second, I
commented on the patch that does something with this driver and pointed out
to the return 0 in some cases. This one seems a band aid.


> +               if (!cs35l41->vspk_always_on)
> +                       gpiod_set_value_cansleep(cs35l41->reset_gpio, 0);
> +               gpiod_put(cs35l41->reset_gpio);
> +       }
>
>         return ret;
>  }
> --
> 2.26.3
>
>

-- 
With Best Regards,
Andy Shevchenko