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Message-ID: <90e259e4-6877-ee1e-ed6e-aa972f305126@canonical.com>
Date:   Wed, 24 Aug 2022 10:10:05 -0700
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Subject: Re: [PATCH] apparmor: fix a memleak in multi_transaction_new()
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To:     Gaosheng Cui <cuigaosheng1@huawei.com>, paul@paul-moore.com,
        jmorris@namei.org, serge@hallyn.com
Cc:     apparmor@lists.ubuntu.com, linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20220823011503.2757088-1-cuigaosheng1@huawei.com>
From:   John Johansen <john.johansen@canonical.com>
Organization: Canonical
In-Reply-To: <20220823011503.2757088-1-cuigaosheng1@huawei.com>
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On 8/22/22 18:15, Gaosheng Cui wrote:
> In multi_transaction_new(), the variable t is not freed or passed out
> on the failure of copy_from_user(t->data, buf, size), which could lead
> to a memleak.
> 
> Fix this bug by adding a put_multi_transaction(t) in the error path.
> 
> Fixes: 1dea3b41e84c5 ("apparmor: speed up transactional queries")
> Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>

yep, thanks. I will pull this into apparmor-next

Acked-by: John Johansen <john.johansen@canonical.com>

> ---
>   security/apparmor/apparmorfs.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
> index d066ccc219e2..7160e7aa58b9 100644
> --- a/security/apparmor/apparmorfs.c
> +++ b/security/apparmor/apparmorfs.c
> @@ -868,8 +868,10 @@ static struct multi_transaction *multi_transaction_new(struct file *file,
>   	if (!t)
>   		return ERR_PTR(-ENOMEM);
>   	kref_init(&t->count);
> -	if (copy_from_user(t->data, buf, size))
> +	if (copy_from_user(t->data, buf, size)) {
> +		put_multi_transaction(t);
>   		return ERR_PTR(-EFAULT);
> +	}
>   
>   	return t;
>   }