Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757529AbYBOSVz (ORCPT ); Fri, 15 Feb 2008 13:21:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754223AbYBOSVr (ORCPT ); Fri, 15 Feb 2008 13:21:47 -0500 Received: from n6.bullet.mail.tp2.yahoo.com ([203.188.202.87]:47742 "HELO n6.bullet.mail.tp2.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752901AbYBOSVq (ORCPT ); Fri, 15 Feb 2008 13:21:46 -0500 X-Greylist: delayed 365 seconds by postgrey-1.27 at vger.kernel.org; Fri, 15 Feb 2008 13:21:45 EST X-Yahoo-Newman-Id: 981134.25122.bm@omp201.mail.sp1.yahoo.com X-YMail-OSG: bvOcEIgVM1ncJivzchi6UZgOdVBRlkdT3gnoL7W7Ct0ltQ6zrOOMMLSl2nLfBsH1u8asKXTPGg-- X-Yahoo-Newman-Property: ymail-3 Message-ID: <47B52569.9040502@schaufler-ca.com> Date: Thu, 14 Feb 2008 21:38:49 -0800 From: Casey Schaufler Reply-To: casey@schaufler-ca.com User-Agent: Thunderbird 2.0.0.9 (Windows/20071031) MIME-Version: 1.0 To: akpm@linux-foundation.org, torvalds@linux-foundation.org, paul.moore@hp.com CC: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, casey@schaufler-ca.com Subject: [PATCH] (02/14/08 Linus git) Smack unlabeled outgoing ambient packets - v3 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8158 Lines: 269 From: Casey Schaufler Smack uses CIPSO labeling, but allows for unlabeled packets by specifying an "ambient" label that is applied to incoming unlabeled packets. Because the other end of the connection may dislike IP options, and ssh is one know application that behaves thus, it is prudent to respond in kind. This patch changes the network labeling behavior such that an outgoing packet that would be given a CIPSO label that matches the ambient label is left unlabeled. An "unlbl" domain is added and the netlabel defaulting mechanism invoked rather than assuming that everything is CIPSO. Locking has been added around changes to the ambient label as the mechanisms used to do so are more involved. Cleaned up some issues noted in review. Make smk_cipso_doi() static. Create a hook for the new security_secctx_to_secid() using existing underlying code. Fill in audit data for netlbl domain calls. Collapse unnecessary multiple assignments. Signed-off-by: Casey Schaufler --- security/smack/smack_lsm.c | 43 ++++++++++++++++++++---- security/smack/smackfs.c | 61 ++++++++++++++++++++++++++--------- 2 files changed, 81 insertions(+), 23 deletions(-) diff -uprN -X linux-2.6.25-g0214-base/Documentation/dontdiff linux-2.6.25-g0214-base/security/smack/smackfs.c linux-2.6.25-g0214/security/smack/smackfs.c --- linux-2.6.25-g0214-base/security/smack/smackfs.c 2008-02-14 15:37:13.000000000 -0800 +++ linux-2.6.25-g0214/security/smack/smackfs.c 2008-02-14 15:42:26.000000000 -0800 @@ -24,6 +24,7 @@ #include #include #include +#include #include "smack.h" /* @@ -45,6 +46,7 @@ enum smk_inos { */ static DEFINE_MUTEX(smack_list_lock); static DEFINE_MUTEX(smack_cipso_lock); +static DEFINE_MUTEX(smack_ambient_lock); /* * This is the "ambient" label for network traffic. @@ -342,6 +344,9 @@ void smk_cipso_doi(void) struct cipso_v4_doi *doip; struct netlbl_audit audit_info; + audit_info.loginuid = audit_get_loginuid(current); + audit_info.secid = smack_to_secid(current->security); + rc = netlbl_cfg_map_del(NULL, &audit_info); if (rc != 0) printk(KERN_WARNING "%s:%d remove rc = %d\n", @@ -363,6 +368,30 @@ void smk_cipso_doi(void) __func__, __LINE__, rc); } +/** + * smk_unlbl_ambient - initialize the unlabeled domain + */ +void smk_unlbl_ambient(char *oldambient) +{ + int rc; + struct netlbl_audit audit_info; + + audit_info.loginuid = audit_get_loginuid(current); + audit_info.secid = smack_to_secid(current->security); + + if (oldambient != NULL) { + rc = netlbl_cfg_map_del(oldambient, &audit_info); + if (rc != 0) + printk(KERN_WARNING "%s:%d remove rc = %d\n", + __func__, __LINE__, rc); + } + + rc = netlbl_cfg_unlbl_add_map(smack_net_ambient, &audit_info); + if (rc != 0) + printk(KERN_WARNING "%s:%d add rc = %d\n", + __func__, __LINE__, rc); +} + /* * Seq_file read operations for /smack/cipso */ @@ -709,7 +738,6 @@ static ssize_t smk_read_ambient(struct f size_t cn, loff_t *ppos) { ssize_t rc; - char out[SMK_LABELLEN]; int asize; if (*ppos != 0) @@ -717,23 +745,18 @@ static ssize_t smk_read_ambient(struct f /* * Being careful to avoid a problem in the case where * smack_net_ambient gets changed in midstream. - * Since smack_net_ambient is always set with a value - * from the label list, including initially, and those - * never get freed, the worst case is that the pointer - * gets changed just after this strncpy, in which case - * the value passed up is incorrect. Locking around - * smack_net_ambient wouldn't be any better than this - * copy scheme as by the time the caller got to look - * at the ambient value it would have cleared the lock - * and been changed. */ - strncpy(out, smack_net_ambient, SMK_LABELLEN); - asize = strlen(out) + 1; + mutex_lock(&smack_ambient_lock); - if (cn < asize) - return -EINVAL; + asize = strlen(smack_net_ambient) + 1; + + if (cn >= asize) + rc = simple_read_from_buffer(buf, cn, ppos, + smack_net_ambient, asize); + else + rc = -EINVAL; - rc = simple_read_from_buffer(buf, cn, ppos, out, asize); + mutex_unlock(&smack_ambient_lock); return rc; } @@ -751,6 +774,7 @@ static ssize_t smk_write_ambient(struct size_t count, loff_t *ppos) { char in[SMK_LABELLEN]; + char *oldambient; char *smack; if (!capable(CAP_MAC_ADMIN)) @@ -766,7 +790,13 @@ static ssize_t smk_write_ambient(struct if (smack == NULL) return -EINVAL; + mutex_lock(&smack_ambient_lock); + + oldambient = smack_net_ambient; smack_net_ambient = smack; + smk_unlbl_ambient(oldambient); + + mutex_unlock(&smack_ambient_lock); return count; } @@ -974,6 +1004,7 @@ static int __init init_smk_fs(void) sema_init(&smack_write_sem, 1); smk_cipso_doi(); + smk_unlbl_ambient(NULL); return err; } diff -uprN -X linux-2.6.25-g0214-base/Documentation/dontdiff linux-2.6.25-g0214-base/security/smack/smack_lsm.c linux-2.6.25-g0214/security/smack/smack_lsm.c --- linux-2.6.25-g0214-base/security/smack/smack_lsm.c 2008-02-14 15:37:13.000000000 -0800 +++ linux-2.6.25-g0214/security/smack/smack_lsm.c 2008-02-14 15:49:29.000000000 -0800 @@ -1251,9 +1251,8 @@ static void smack_to_secattr(char *smack switch (smack_net_nltype) { case NETLBL_NLTYPE_CIPSOV4: - nlsp->domain = NULL; - nlsp->flags = NETLBL_SECATTR_DOMAIN; - nlsp->flags |= NETLBL_SECATTR_MLS_LVL; + nlsp->domain = kstrdup(smack, GFP_ATOMIC); + nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL; rc = smack_to_cipso(smack, &cipso); if (rc == 0) { @@ -1282,15 +1281,21 @@ static int smack_netlabel(struct sock *s { struct socket_smack *ssp; struct netlbl_lsm_secattr secattr; - int rc = 0; + int rc; ssp = sk->sk_security; netlbl_secattr_init(&secattr); smack_to_secattr(ssp->smk_out, &secattr); - if (secattr.flags != NETLBL_SECATTR_NONE) - rc = netlbl_sock_setattr(sk, &secattr); - + rc = netlbl_sock_setattr(sk, &secattr); netlbl_secattr_destroy(&secattr); + + /* + * A return of -ENOENT from netlbl_sock_setattr + * indicates that the "domain" was not found, but that's + * not an issue because of the defaulting behavior. + */ + if (rc == -ENOENT) + rc = 0; return rc; } @@ -1313,6 +1318,7 @@ static int smack_inode_setsecurity(struc struct inode_smack *nsp = inode->i_security; struct socket_smack *ssp; struct socket *sock; + int rc = 0; if (value == NULL || size > SMK_LABELLEN) return -EACCES; @@ -1341,7 +1347,10 @@ static int smack_inode_setsecurity(struc ssp->smk_in = sp; else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { ssp->smk_out = sp; - return smack_netlabel(sock->sk); + rc = smack_netlabel(sock->sk); + if (rc != 0) + printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n", + __func__, -rc); } else return -EOPNOTSUPP; @@ -2214,6 +2223,9 @@ static void smack_sock_graft(struct sock ssp->smk_packet[0] = '\0'; rc = smack_netlabel(sk); + if (rc != 0) + printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n", + __func__, -rc); } /** @@ -2346,6 +2358,20 @@ static int smack_secid_to_secctx(u32 sec } /* + * smack_secctx_to_secid - return the secid for a smack label + * @secdata: smack label + * @seclen: how long result is + * @secid: outgoing integer + * + * Exists for audit and networking code. + */ +static int smack_secctx_to_secid(char *secdata, u32 seclen, u32 *secid) +{ + *secid = smack_to_secid(secdata); + return 0; +} + +/* * smack_release_secctx - don't do anything. * @key_ref: unused * @context: unused @@ -2475,6 +2501,7 @@ static struct security_operations smack_ .key_permission = smack_key_permission, #endif /* CONFIG_KEYS */ .secid_to_secctx = smack_secid_to_secctx, + .secctx_to_secid = smack_secctx_to_secid, .release_secctx = smack_release_secctx, }; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/