Re: [PATCH] (2.6.24-rc8-mm1) -mm v2 Smack socket label setting fix

From: Paul Moore
Date: Tue Jan 22 2008 - 17:14:03 EST


On Saturday 19 January 2008 6:04:52 pm Casey Schaufler wrote:
> From: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
>
> Correct the checks in smack_inode_setxattr to include the
> socket labeling attributes. Simplify and correct
> smack_sock_graft, while the values it was setting were
> safe they were not correct and the job was not being
> done efficiently. smack_inode_setsecurity wasn't
> invoking the required netlabel function in the case
> where smk_ipout was set. It does now, but that change
> required the hook to be moved in the file. This
> movement accounts for the bulk of the patch.
>
>
> Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>

...

> +/**
> * smack_socket_post_create - finish socket setup
> * @sock: the socket
> * @family: protocol family
> @@ -2192,33 +2199,20 @@ static int smack_socket_getpeersec_dgram
> static void smack_sock_graft(struct sock *sk, struct socket *parent)
> {
> struct socket_smack *ssp;
> - struct netlbl_lsm_secattr secattr;
> - char smack[SMK_LABELLEN];
> int rc;

I don't think you need 'rc'.

> - if (sk == NULL || parent == NULL || parent->sk == NULL)
> + if (sk == NULL)
> return;

I'm pretty sure you don't need to check 'sk' to ensure it is non-NULL;
SELinux assumes 'sk' is non-NULL and it hasn't caused any problems.

> if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
> return;
>
> - ssp = parent->sk->sk_security;
> -
> - memset(smack, '\0', SMK_LABELLEN);
> - netlbl_secattr_init(&secattr);
> - rc = netlbl_sock_getattr(sk, &secattr);
> - if (rc == 0)
> - smack_from_secattr(&secattr, smack);
> - else
> - strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
> - netlbl_secattr_destroy(&secattr);
> -
> - netlbl_secattr_init(&secattr);
> + ssp = sk->sk_security;
> + ssp->smk_in = current->security;
> + ssp->smk_out = current->security;
> + ssp->smk_packet[0] = '\0';
>
> - smack_to_secattr(smack, &secattr);
> - if (secattr.flags != NETLBL_SECATTR_NONE)
> - rc = netlbl_sock_setattr(parent->sk, &secattr);
> - netlbl_secattr_destroy(&secattr);
> + rc = smack_netlabel(sk);

I haven't checked the latest SMACK bits, but I'm pretty sure you don't
need to assign the return value of 'smack_netlabel()' to anything here
since the function doesn't return a value.

> }
>
> /**



--
paul moore
linux security @ hp
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