linux-kernel - Re: [RFC][PATCH 5/7] smack: import the security label in smack_secctx_to

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4DB8AAFA.2050903@schaufler-ca.com>
Date:	Wed, 27 Apr 2011 16:47:06 -0700
From:	Casey Schaufler <casey@...aufler-ca.com>
To:	Roberto Sassu <roberto.sassu@...ito.it>
CC:	linux-security-module@...r.kernel.org,
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
	dhowells@...hat.com, jmorris@...ei.org, zohar@...ux.vnet.ibm.com,
	safford@...son.ibm.com, tyhicks@...ux.vnet.ibm.com,
	kirkland@...onical.com, ecryptfs-devel@...ts.launchpad.net,
	eparis@...hat.com, sds@...ho.nsa.gov, selinux@...ho.nsa.gov,
	viro@...iv.linux.org.uk, Casey Schaufler <casey@...aufler-ca.com>
Subject: Re: [RFC][PATCH 5/7] smack: import the security label in smack_secctx_to_secid()

On 4/27/2011 5:34 AM, Roberto Sassu wrote:
> The security label passed as argument in smack_secctx_to_secid() must be
> first imported in the 'smack_known_list' list before finding the security
> identifier associated to it. This allows the function
> set_security_override_from_ctx() to be performed successfully even if the
> label is not yet present in the smack list.
>
> Signed-off-by: Roberto Sassu <roberto.sassu@...ito.it>

Nacked-by: Casey Schaufler <casey@...aufler-ca.com>

security_secctx_to_secid() is called from the netlabel code
and hence cannot (to my understanding) allocate memory,
which is something that smk_import will do if the label is
new. I am willing to be convinced that doing so is safe,
but my understanding is that it is not.

> ---
>  security/smack/smack_lsm.c |    8 +++++++-
>  1 files changed, 7 insertions(+), 1 deletions(-)
>
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 0e7ed31..6612ba1 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -3346,7 +3346,13 @@ static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
>   */
>  static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
>  {
> -	*secid = smack_to_secid(secdata);
> +	char *smack;
> +
> +	smack = smk_import(secdata, seclen);
> +	if (smack == NULL)
> +		return -EINVAL;
> +
> +	*secid = smack_to_secid(smack);
>  	return 0;
>  }
>  

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/