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Message-ID: <3c47940d-06e2-6c08-280c-76f7a365cf0b@canonical.com>
Date:   Tue, 4 Oct 2022 02:52:03 -0700
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Subject: Re: [PATCH] apparmor: store return value of unpack_perms_table() to
 signed variable
Content-Language: en-US
To:     Muhammad Usama Anjum <usama.anjum@collabora.com>,
        Paul Moore <paul@paul-moore.com>,
        James Morris <jmorris@namei.org>,
        "Serge E. Hallyn" <serge@hallyn.com>
Cc:     kernel@collabora.com, kernel-janitors@vger.kernel.org,
        apparmor@lists.ubuntu.com, linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20221004084515.659441-1-usama.anjum@collabora.com>
From:   John Johansen <john.johansen@canonical.com>
Organization: Canonical
In-Reply-To: <20221004084515.659441-1-usama.anjum@collabora.com>
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On 10/4/22 01:45, Muhammad Usama Anjum wrote:
> The unpack_perms_table() can return error which is negative value. Store
> the return value to a signed variable. policy->size is unsigned
> variable. It shouldn't be used to store the return status.
> 
> Fixes: 2d6b2dea7f3c ("apparmor: add the ability for policy to specify a permission table")
> Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>

yep, thanks I have pulled this in

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

> ---
>   security/apparmor/policy_unpack.c | 12 ++++++++----
>   1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c
> index 45c9dfdc8e0d..09f316943951 100644
> --- a/security/apparmor/policy_unpack.c
> +++ b/security/apparmor/policy_unpack.c
> @@ -734,14 +734,18 @@ static int unpack_pdb(struct aa_ext *e, struct aa_policydb *policy,
>   {
>   	void *pos = e->pos;
>   	int i, flags, error = -EPROTO;
> +	ssize_t size;
>   
> -	policy->size = unpack_perms_table(e, &policy->perms);
> -	if (policy->size < 0) {
> -		error = policy->size;
> +	size = unpack_perms_table(e, &policy->perms);
> +	if (size < 0) {
> +		error = size;
>   		policy->perms = NULL;
>   		*info = "failed to unpack - perms";
>   		goto fail;
> -	} else if (policy->perms) {
> +	}
> +	policy->size = size;
> +
> +	if (policy->perms) {
>   		/* perms table present accept is index */
>   		flags = TO_ACCEPT1_FLAG(YYTD_DATA32);
>   	} else {