Re: [PATCH] ALSA: hda: Fix missing pointer check in hda_component_manager_init function

[Takashi Iwai <tiwai@suse.de>]

On Tue, 07 Oct 2025 10:39:57 +0200,
Denis Arefev wrote:
> 
> The __component_match_add function may assign the 'matchptr' pointer
> the value ERR_PTR(-ENOMEM), which will subsequently be dereferenced.
> 
> The call stack leading to the error looks like this: 
> 
> hda_component_manager_init
> |-> component_match_add
>     |-> component_match_add_release
>         |-> __component_match_add ( ... ,**matchptr, ... )
>             |-> *matchptr = ERR_PTR(-ENOMEM);       // assign 
> |-> component_master_add_with_match( ...  match)
>     |-> component_match_realloc(match, match->num); // dereference
> 
> Add IS_ERR() check to prevent the crash.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.          
> 
> Fixes: fd895a74dc1d ("ALSA: hda: realtek: Move hda_component implementation to module")
> Cc: stable@vger.kernel.org
> Signed-off-by: Denis Arefev <arefev@swemel.ru>

Thanks for the patch.

The Fixes tag isn't 100% correct, though; the given commit just moves
the code into another file, and the lack of the return value from
component_match_add() was present even before that commit, too.


Takashi


> ---
>  sound/hda/codecs/side-codecs/hda_component.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/sound/hda/codecs/side-codecs/hda_component.c b/sound/hda/codecs/side-codecs/hda_component.c
> index 71860e2d6377..84ddbab660e3 100644
> --- a/sound/hda/codecs/side-codecs/hda_component.c
> +++ b/sound/hda/codecs/side-codecs/hda_component.c
> @@ -181,6 +181,8 @@ int hda_component_manager_init(struct hda_codec *cdc,
>  		sm->match_str = match_str;
>  		sm->index = i;
>  		component_match_add(dev, &match, hda_comp_match_dev_name, sm);
> +		if (IS_ERR(match))
> +			return PTR_ERR(match);
>  	}
>  
>  	ret = component_master_add_with_match(dev, ops, match);
> -- 
> 2.43.0
>