[Intel-gfx] [PATCH] drm/i915: Avoid leaking lpe audio platdev.data

[Jani Nikula]

On Sat, 09 Dec 2017, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> The struct platform_device memdups the provided data pointer requiring
> us to free the template we construct during lpe_audio_platdev_create():
>
> unreferenced object 0xffff88026eafe400 (size 512):
>   comm "insmod", pid 6850, jiffies 4295060179 (age 22.300s)
>   hex dump (first 32 bytes):
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>   backtrace:
>     [<000000008e4a834c>] intel_audio_init+0x9/0x30 [i915]
>     [<000000001360e195>] i915_driver_load+0x802/0x14e0 [i915]
>     [<00000000ab3f0e99>] i915_pci_probe+0x29/0x70 [i915]
>     [<0000000016330ee5>] pci_device_probe+0x9c/0x120
>     [<000000000257d054>] driver_probe_device+0x307/0x470
>     [<000000009f0a6cb6>] __driver_attach+0x98/0xe0
>     [<0000000031b46e58>] bus_for_each_dev+0x57/0x80
>     [<000000000e28239d>] bus_add_driver+0x1bd/0x260
>     [<00000000abbe5161>] driver_register+0x52/0xc0
>     [<000000005c6e23d4>] do_one_initcall+0x36/0x150
>     [<00000000a55002f4>] do_init_module+0x56/0x1d7
>     [<00000000e48f2217>] load_module+0x23c8/0x2910
>     [<000000002b60bf61>] SyS_finit_module+0xb8/0xd0
>     [<0000000041cbad96>] entry_SYSCALL_64_fastpath+0x17/0x70
>     [<000000009f1d37ab>] 0xffffffffffffffff
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Takashi Iwai <tiwai at suse.de>
> Cc: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>

I queued this for re-testing.

Reviewed-by: Jani Nikula <jani.nikula at intel.com>

> ---
>  drivers/gpu/drm/i915/intel_lpe_audio.c | 14 ++++----------
>  1 file changed, 4 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_lpe_audio.c b/drivers/gpu/drm/i915/intel_lpe_audio.c
> index 3bf65288ffff..0a2e1fea43fa 100644
> --- a/drivers/gpu/drm/i915/intel_lpe_audio.c
> +++ b/drivers/gpu/drm/i915/intel_lpe_audio.c
> @@ -74,7 +74,6 @@
>  static struct platform_device *
>  lpe_audio_platdev_create(struct drm_i915_private *dev_priv)
>  {
> -	int ret;
>  	struct drm_device *dev = &dev_priv->drm;
>  	struct platform_device_info pinfo = {};
>  	struct resource *rsc;
> @@ -119,24 +118,19 @@ lpe_audio_platdev_create(struct drm_i915_private *dev_priv)
>  	spin_lock_init(&pdata->lpe_audio_slock);
>  
>  	platdev = platform_device_register_full(&pinfo);
> +	kfree(rsc);
> +	kfree(pdata);
> +
>  	if (IS_ERR(platdev)) {
> -		ret = PTR_ERR(platdev);
>  		DRM_ERROR("Failed to allocate LPE audio platform device\n");
> -		goto err;
> +		return platdev;
>  	}
>  
> -	kfree(rsc);
> -
>  	pm_runtime_forbid(&platdev->dev);
>  	pm_runtime_set_active(&platdev->dev);
>  	pm_runtime_enable(&platdev->dev);
>  
>  	return platdev;
> -
> -err:
> -	kfree(rsc);
> -	kfree(pdata);
> -	return ERR_PTR(ret);
>  }
>  
>  static void lpe_audio_platdev_destroy(struct drm_i915_private *dev_priv)

-- 
Jani Nikula, Intel Open Source Technology Center