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Message-ID: <87f35305-324e-6f7a-69a6-710db05c6e7c@canonical.com>
Date:   Wed, 26 Jan 2022 01:30:54 -0800
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Subject: Re: [PATCH][next] apparmor: Use struct_size() helper in kmalloc()
Content-Language: en-US
To:     "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        James Morris <jmorris@namei.org>,
        "Serge E. Hallyn" <serge@hallyn.com>
Cc:     linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
References: <20220125015606.GA28243@embeddedor>
From:   John Johansen <john.johansen@canonical.com>
Organization: Canonical
In-Reply-To: <20220125015606.GA28243@embeddedor>
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On 1/24/22 17:56, Gustavo A. R. Silva wrote:
> Make use of the struct_size() helper instead of an open-coded version,
> in order to avoid any potential type mistakes or integer overflows that,
> in the worst scenario, could lead to heap overflows.
> 
> Also, address the following sparse warnings:
> security/apparmor/lib.c:139:23: warning: using sizeof on a flexible structure
> 
> Link: https://github.com/KSPP/linux/issues/174
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

thanks, I have pulled this into my tree
Acked-by: John Johansen <john.johansen@canonical.com>

> ---
>  security/apparmor/lib.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/security/apparmor/lib.c b/security/apparmor/lib.c
> index fa49b81eb54c..5eda003c0d45 100644
> --- a/security/apparmor/lib.c
> +++ b/security/apparmor/lib.c
> @@ -136,7 +136,7 @@ __counted char *aa_str_alloc(int size, gfp_t gfp)
>  {
>  	struct counted_str *str;
>  
> -	str = kmalloc(sizeof(struct counted_str) + size, gfp);
> +	str = kmalloc(struct_size(str, name, size), gfp);
>  	if (!str)
>  		return NULL;
>