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Date: Tue, 9 Jul 2024 15:32:50 +0200
From: Greg KH <gregkh@linuxfoundation.org>
To: Ma Ke <make24@iscas.ac.cn>
Cc: fbarrat@linux.ibm.com, ajd@linux.ibm.com, arnd@arndb.de,
	manoj@linux.vnet.ibm.com, mpe@ellerman.id.au,
	clombard@linux.vnet.ibm.com, imunsie@au1.ibm.com,
	linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Subject: Re: [PATCH] cxl: Fix possible null pointer dereference in
 read_handle()
Message-ID: <2024070940-customize-sturdily-fc81@gregkh>
References: <20240709131754.855144-1-make24@iscas.ac.cn>
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In-Reply-To: <20240709131754.855144-1-make24@iscas.ac.cn>

On Tue, Jul 09, 2024 at 09:17:54PM +0800, Ma Ke wrote:
> In read_handle() of_get_address() may return NULL which is later
> dereferenced. Fix this bug by adding NULL check.
> 
> Cc: stable@vger.kernel.org
> Fixes: 14baf4d9c739 ("cxl: Add guest-specific code")
> Signed-off-by: Ma Ke <make24@iscas.ac.cn>
> ---
>  drivers/misc/cxl/of.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/cxl/of.c b/drivers/misc/cxl/of.c
> index bcc005dff1c0..d8dbb3723951 100644
> --- a/drivers/misc/cxl/of.c
> +++ b/drivers/misc/cxl/of.c
> @@ -58,7 +58,7 @@ static int read_handle(struct device_node *np, u64 *handle)
>  
>  	/* Get address and size of the node */
>  	prop = of_get_address(np, 0, &size, NULL);
> -	if (size)
> +	if (!prop || size)
>  		return -EINVAL;

How was this issue found?

thanks,

greg k-h