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Date: Thu, 18 Jan 2024 08:29:20 +0300
From: Dan Carpenter <dan.carpenter@linaro.org>
To: Markus Elfring <Markus.Elfring@web.de>
Cc: linux-hardening@vger.kernel.org, kernel-janitors@vger.kernel.org,
	"Guilherme G. Piccoli" <gpiccoli@igalia.com>,
	Joel Fernandes <joel@joelfernandes.org>,
	Kees Cook <keescook@chromium.org>, Tony Luck <tony.luck@intel.com>,
	LKML <linux-kernel@vger.kernel.org>,
	=?iso-8859-1?Q?G=FCnter_R=F6ck?= <groeck@chromium.org>,
	Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>,
	Kunwu Chan <chentao@kylinos.cn>
Subject: Re: [PATCH] pstore/ram: Return directly after a failed kasprintf()
 call in ramoops_init_prz()
Message-ID: <26759e3b-ff74-4b04-b06f-4d68fbc5f606@moroto.mountain>
References: <644f44ad-7e2b-4a1a-bbd7-ccc79d479242@web.de>
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In-Reply-To: <644f44ad-7e2b-4a1a-bbd7-ccc79d479242@web.de>

On Wed, Jan 17, 2024 at 09:24:12PM +0100, Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Wed, 17 Jan 2024 21:09:22 +0100
> 
> The result from a call of the function “kasprintf” was passed to
> a subsequent function call without checking for a null pointer before
> (according to a memory allocation failure).
> This issue was detected by using the Coccinelle software.
> 
> Thus return directly after a failed kasprintf() call.
> 
> Fixes: 1227daa43bce1 ("pstore/ram: Clarify resource reservation labels")
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
>  fs/pstore/ram.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
> index 88b34fdbf759..1a673a4af17c 100644
> --- a/fs/pstore/ram.c
> +++ b/fs/pstore/ram.c
> @@ -595,6 +595,9 @@ static int ramoops_init_prz(const char *name,
>  	}
> 
>  	label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
> +	if (!label)
> +		return -ENOMEM;
> +
>  	*prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
>  				  cxt->memtype, PRZ_FLAG_ZAP_OLD, label);
>  	kfree(label);

This patch is fine as a clean up, but I think it's useful to say that
if you pass a NULL label to persistent_ram_new() then it will return
an error.  It won't crash.  So this patch is a nice cleanup but it's not
a bug fix.

regards,
dan carpenter