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Date: Thu, 18 Dec 2025 12:23:55 +0100
From: Greg KH <gregkh@linuxfoundation.org>
To: Haoxiang Li <lihaoxiang@isrc.iscas.ac.cn>
Cc: perex@perex.cz, rafael@kernel.org, linux-acpi@vger.kernel.org,
	linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH] PNP: add a put_device() in isapnp_init()
Message-ID: <2025121835-flattop-july-3c62@gregkh>
References: <20251218083646.553049-1-lihaoxiang@isrc.iscas.ac.cn>
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In-Reply-To: <20251218083646.553049-1-lihaoxiang@isrc.iscas.ac.cn>

On Thu, Dec 18, 2025 at 04:36:46PM +0800, Haoxiang Li wrote:
> if pnp_register_protocol() fails, call put_device()
> to drop the device reference.
> 
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Cc: stable@vger.kernel.org
> Signed-off-by: Haoxiang Li <lihaoxiang@isrc.iscas.ac.cn>
> ---
>  drivers/pnp/isapnp/core.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pnp/isapnp/core.c b/drivers/pnp/isapnp/core.c
> index 219f96f2aaaf..d6daab7ed59e 100644
> --- a/drivers/pnp/isapnp/core.c
> +++ b/drivers/pnp/isapnp/core.c
> @@ -983,8 +983,10 @@ static int __init isapnp_init(void)
>  		return -EBUSY;
>  	}
>  
> -	if (pnp_register_protocol(&isapnp_protocol) < 0)
> +	if (pnp_register_protocol(&isapnp_protocol) < 0) {
> +		put_device(&isapnp_protocol.dev);

Same here, this feels very wrong.

How was this tested?

How was this found?

thanks,

greg k-h