From: Al Viro <viro@ftp.linux.org.uk>
To: Casey Schaufler <casey@schaufler-ca.com>
Cc: torvalds@osdl.org, akpm@osdl.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Version 8 (2.6.23) Smack: Simplified Mandatory Access Control Kernel
Date: Thu, 18 Oct 2007 05:57:05 +0100 [thread overview]
Message-ID: <20071018045705.GM8181@ftp.linux.org.uk> (raw)
In-Reply-To: <47158CE4.30706@schaufler-ca.com>
On Tue, Oct 16, 2007 at 09:17:40PM -0700, Casey Schaufler wrote:
At random:
> +static int smack_netlabel(struct sock *sk)
> +{
> + static int initialized;
> + struct socket_smack *ssp = sk->sk_security;
> + struct netlbl_lsm_secattr secattr;
> + int rc = 0;
> +
> + if (!initialized) {
> + smk_cipso_doi();
> + initialized = 1;
> + }
And just what happens if another task calls the same while we are
blocked on allocation in smk_cipso_doi()?
Another problem is your handling of smk_known - you add to head under
mutex; fine. However, you read without one _and_ have no barriers
in initializing new list entries.
Think what happens if CPU1 adds to list and CPU2 sees write to smk_known
*before* it sees write to ->smk_next. We see a single-element list and
we'll be lucky if that single entry won't be FUBAR.
next prev parent reply other threads:[~2007-10-18 4:57 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-17 4:17 [PATCH] Version 8 (2.6.23) Smack: Simplified Mandatory Access Control Kernel Casey Schaufler
2007-10-18 4:57 ` Al Viro [this message]
2007-10-18 5:10 ` Al Viro
2007-10-19 12:39 ` Ahmed S. Darwish
2007-10-18 20:13 ` Casey Schaufler
2007-10-18 20:26 ` Al Viro
2007-10-21 1:40 ` [PATCH] Smackv8: Omit non-cipso labels in cipso_seq_start Ahmed S. Darwish
2007-10-21 2:25 ` [PATCH] Smackv8: Safe lockless {cipso,load} read operation Ahmed S. Darwish
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