Re: [PATCH v2] selinux: replace BUG_ONs with WARN_ONs in avc.c

From: Stephen Smalley <sds@tycho.nsa.gov>
To: Ondrej Mosnacek <omosnace@redhat.com>,
	selinux@vger.kernel.org, Paul Moore <paul@paul-moore.com>
Subject: Re: [PATCH v2] selinux: replace BUG_ONs with WARN_ONs in avc.c
Date: Mon, 28 Jan 2019 11:06:38 -0500	[thread overview]
Message-ID: <84f36c6a-f267-95eb-fd66-81592ecf1875@tycho.nsa.gov> (raw)
In-Reply-To: <20190128154333.31279-1-omosnace@redhat.com>

On 1/28/19 10:43 AM, Ondrej Mosnacek wrote:
> These checks are only guarding against programming errors that could
> silently grant too many permissions. These cases are better handled with
> WARN_ON(), since it doesn't really help much to crash the machine in
> this case.
> 
> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>

Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>

> ---
>   security/selinux/avc.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/security/selinux/avc.c b/security/selinux/avc.c
> index 3a27418b20d7..33863298a9b5 100644
> --- a/security/selinux/avc.c
> +++ b/security/selinux/avc.c
> @@ -1059,7 +1059,8 @@ int avc_has_extended_perms(struct selinux_state *state,
>   	int rc = 0, rc2;
>   
>   	xp_node = &local_xp_node;
> -	BUG_ON(!requested);
> +	if (WARN_ON(!requested))
> +		return -EACCES;
>   
>   	rcu_read_lock();
>   
> @@ -1149,7 +1150,8 @@ inline int avc_has_perm_noaudit(struct selinux_state *state,
>   	int rc = 0;
>   	u32 denied;
>   
> -	BUG_ON(!requested);
> +	if (WARN_ON(!requested))
> +		return -EACCES;
>   
>   	rcu_read_lock();
>   
>