Re: [PATCH 5/5] staging: media: ipu7: fix double-free of pdata in error paths

[Dan Carpenter <error27@gmail.com>]

On Sun, Apr 12, 2026 at 10:51:28PM +0200, Alexandru Hossu wrote:
> In both ipu7_isys_init() and ipu7_psys_init(), pdata is allocated and
> then passed to ipu7_bus_initialize_device(), which stores it in
> adev->pdata. The ipu7_bus_release() function frees adev->pdata when the
> device's reference count drops to zero.
> 
> Two error paths incorrectly call kfree(pdata) after the device teardown
> has already freed it:
> 
> 1. When ipu7_mmu_init() fails: put_device() is called, which drops the
>    reference count to zero and triggers ipu7_bus_release() ->
>    kfree(pdata). The subsequent kfree(pdata) is a double-free.
> 
> 2. When ipu7_bus_add_device() fails: it calls auxiliary_device_uninit()
>    internally, which calls put_device() -> ipu7_bus_release() ->
>    kfree(pdata). The subsequent kfree(pdata) is again a double-free.
> 
> Note that the kfree(pdata) when ipu7_bus_initialize_device() itself
> fails is correct, because in that case auxiliary_device_init() failed
> and the release function was never set up, so pdata must be freed
> manually.
> 
> Remove the redundant kfree(pdata) calls from the two affected error
> paths.
> 
> Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>

We need a Fixes tag.

> ---
>  drivers/staging/media/ipu7/ipu7.c | 10 ++--------
>  1 file changed, 2 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/staging/media/ipu7/ipu7.c b/drivers/staging/media/ipu7/ipu7.c
> index c771e763f8c5..043b67dfe19a 100644
> --- a/drivers/staging/media/ipu7/ipu7.c
> +++ b/drivers/staging/media/ipu7/ipu7.c
> @@ -2172,7 +2172,6 @@ ipu7_isys_init(struct pci_dev *pdev, struct device *parent,
>  		dev_err_probe(dev, PTR_ERR(isys_adev->mmu),
>  			      "ipu7_mmu_init(isys_adev->mmu) failed\n");
>  		put_device(&isys_adev->auxdev.dev);
> -		kfree(pdata);
>  		return ERR_CAST(isys_adev->mmu);
                                ^^^^^^^^^^^^^^
The put_device() frees isys_adev as well so this is a use after free.

		ret = dev_err_probe(dev, PTR_ERR(isys_adev->mmu), ...
		put_device();
		return ret;

>  	}
>  
> @@ -2180,10 +2179,8 @@ ipu7_isys_init(struct pci_dev *pdev, struct device *parent,
>  	isys_adev->subsys = IPU_IS;
>  
>  	ret = ipu7_bus_add_device(isys_adev);
> -	if (ret) {
> -		kfree(pdata);
> +	if (ret)
>  		return ERR_PTR(ret);
> -	}
>  
>  	return isys_adev;
>  }
> @@ -2219,7 +2216,6 @@ ipu7_psys_init(struct pci_dev *pdev, struct device *parent,
>  		dev_err_probe(&pdev->dev, PTR_ERR(psys_adev->mmu),
>  			      "ipu7_mmu_init(psys_adev->mmu) failed\n");
>  		put_device(&psys_adev->auxdev.dev);
> -		kfree(pdata);
>  		return ERR_CAST(psys_adev->mmu);

Same here?

regards,
dan carpenter


>  	}
>