Stephen,
my reply follows your quoted text.
>On Mon, 2010-02-01 at 22:49 +0100, Guido Trentalancia wrote:
>> + if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
>> + oc = args->newp->ocontexts[OCON_ISID];
>> + while (oc && oc->sid[0] != SECINITSID_UNLABELED)
>> + oc = oc->next;
>
>Just in case, I'd test if (!oc) and bail with an error.
if (!oc) {
printk(KERN_ERR "SELinux: unable to look up"
" the initial SIDs listn");
goto bad;
}
>> + range = &oc->context[0].range;
>> + rc = mls_range_set(c, range);
>> + if (rc) {
>> + if (context_struct_to_string(&oldc, &s, &len))
>> + return -ENOMEM;
>> + context_destroy(&oldc);
>> + context_destroy(c);
>> + c->str = s;
>> + c->len = len;
>> + printk(KERN_ERR "SELinux: Failed to set"
>> + " the MLS/MCS range for context"
>> + " %sn", c->str);
>> + goto out;
>
>goto bad ?
Ok, goto bad. It improves readability.
Final version follows. You don't like to appear as any of Acked-by, Signed-off-by or Reviewed-by ? Nobody else commented, I would say it's ready to be submitted then (has been reviewed, checks fine, builds fine, diffstat included and I will have a kernel ready in a few minutes for a final test just in case).
Author: Guido Trentalancia <guido@xxxxxxxxxxxxxxxx>
Date: Mon Feb 01 23:29:52 2010 +0100
Allow runtime switching between different policy types (e.g. from a MLS/MCS
policy to a non-MLS/non-MCS policy or viceversa).
Signed-off-by: Guido Trentalancia <guido@xxxxxxxxxxxxxxxx>
security/selinux/include/security.h | 3 -
security/selinux/selinuxfs.c | 3 -
security/selinux/ss/.policydb.c.swp |binary
security/selinux/ss/context.h | 9 +--
security/selinux/ss/mls.c | 26 ++++-----
security/selinux/ss/mls.h | 2
security/selinux/ss/mls_types.h | 5 +
security/selinux/ss/policydb.c | 24 +-------
security/selinux/ss/policydb.h | 4 +
security/selinux/ss/services.c | 74 +++++++++++++++++++++++---
10 files changed, 101 insertions(+), 49 deletions(-)
diff -pruN security-testing-2.6/security/selinux/include/security.h security-testing-2.6-new/security/selinux/include/security.h
--- security-testing-2.6/security/selinux/include/security.h 2010-01-29 02:02:47.737045258 +0100
+++ security-testing-2.6-new/security/selinux/include/security.h 2010-02-01 23:12:28.898233272 +0100
@@ -57,7 +57,6 @@
struct netlbl_lsm_secattr;
extern int selinux_enabled;
-extern int selinux_mls_enabled;
/* Policy capabilities */
enum {
@@ -80,6 +79,8 @@ extern int selinux_policycap_openperm;
/* limitation of boundary depth */
#define POLICYDB_BOUNDS_MAXDEPTH 4
+int security_mls_enabled(void);
+
int security_load_policy(void *data, size_t len);
int security_policycap_supported(unsigned int req_cap);
diff -pruN security-testing-2.6/security/selinux/selinuxfs.c security-testing-2.6-new/security/selinux/selinuxfs.c
--- security-testing-2.6/security/selinux/selinuxfs.c 2010-01-29 02:02:47.738046835 +0100
+++ security-testing-2.6-new/security/selinux/selinuxfs.c 2010-02-01 22:06:21.709234039 +0100
@@ -282,7 +282,8 @@ static ssize_t sel_read_mls(struct file
char tmpbuf[TMPBUFLEN];
ssize_t length;
- length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_mls_enabled);
+ length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
+ security_mls_enabled());
return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}
diff -pruN security-testing-2.6/security/selinux/ss/context.h security-testing-2.6-new/security/selinux/ss/context.h
--- security-testing-2.6/security/selinux/ss/context.h 2010-01-29 01:06:42.160060332 +0100
+++ security-testing-2.6-new/security/selinux/ss/context.h 2010-02-01 23:13:35.857235582 +0100
@@ -41,7 +41,7 @@ static inline int mls_context_cpy(struct
{
int rc;
- if (!selinux_mls_enabled)
+ if (!security_mls_enabled())
return 0;
dst->range.level[0].sens = src->range.level[0].sens;
@@ -64,7 +64,7 @@ static inline int mls_context_cpy_low(st
{
int rc;
- if (!selinux_mls_enabled)
+ if (!security_mls_enabled())
return 0;
dst->range.level[0].sens = src->range.level[0].sens;
@@ -82,7 +82,7 @@ out:
static inline int mls_context_cmp(struct context *c1, struct context *c2)
{
- if (!selinux_mls_enabled)
+ if (!security_mls_enabled())
return 1;
return ((c1->range.level[0].sens == c2->range.level[0].sens) &&
@@ -93,9 +93,6 @@ static inline int mls_context_cmp(struct
static inline void mls_context_destroy(struct context *c)
{
- if (!selinux_mls_enabled)
- return;
-
ebitmap_destroy(&c->range.level[0].cat);
ebitmap_destroy(&c->range.level[1].cat);
mls_context_init(c);
diff -pruN security-testing-2.6/security/selinux/ss/mls.c security-testing-2.6-new/security/selinux/ss/mls.c
--- security-testing-2.6/security/selinux/ss/mls.c 2010-01-29 02:02:47.739046177 +0100
+++ security-testing-2.6-new/security/selinux/ss/mls.c 2010-02-01 22:15:48.062233721 +0100
@@ -39,7 +39,7 @@ int mls_compute_context_len(struct conte
struct ebitmap *e;
struct ebitmap_node *node;
- if (!selinux_mls_enabled)
+ if (!policydb.mls_enabled)
return 0;
len = 1; /* for the beginning ":" */
@@ -93,7 +93,7 @@ void mls_sid_to_context(struct context *
struct ebitmap *e;
struct ebitmap_node *node;
- if (!selinux_mls_enabled)
+ if (!policydb.mls_enabled)
return;
scontextp = *scontext;
@@ -200,7 +200,7 @@ int mls_context_isvalid(struct policydb
{
struct user_datum *usrdatum;
- if (!selinux_mls_enabled)
+ if (!p->mls_enabled)
return 1;
if (!mls_range_isvalid(p, &c->range))
@@ -253,7 +253,7 @@ int mls_context_to_sid(struct policydb *
struct cat_datum *catdatum, *rngdatum;
int l, rc = -EINVAL;
- if (!selinux_mls_enabled) {
+ if (!pol->mls_enabled) {
if (def_sid != SECSID_NULL && oldc)
*scontext += strlen(*scontext)+1;
return 0;
@@ -387,7 +387,7 @@ int mls_from_string(char *str, struct co
char *tmpstr, *freestr;
int rc;
- if (!selinux_mls_enabled)
+ if (!policydb.mls_enabled)
return -EINVAL;
/* we need freestr because mls_context_to_sid will change
@@ -407,7 +407,7 @@ int mls_from_string(char *str, struct co
/*
* Copies the MLS range `range' into `context'.
*/
-static inline int mls_range_set(struct context *context,
+int mls_range_set(struct context *context,
struct mls_range *range)
{
int l, rc = 0;
@@ -427,7 +427,7 @@ static inline int mls_range_set(struct c
int mls_setup_user_range(struct context *fromcon, struct user_datum *user,
struct context *usercon)
{
- if (selinux_mls_enabled) {
+ if (policydb.mls_enabled) {
struct mls_level *fromcon_sen = &(fromcon->range.level[0]);
struct mls_level *fromcon_clr = &(fromcon->range.level[1]);
struct mls_level *user_low = &(user->range.level[0]);
@@ -477,7 +477,7 @@ int mls_convert_context(struct policydb
struct ebitmap_node *node;
int l, i;
- if (!selinux_mls_enabled)
+ if (!policydb.mls_enabled)
return 0;
for (l = 0; l < 2; l++) {
@@ -516,7 +516,7 @@ int mls_compute_sid(struct context *scon
struct range_trans rtr;
struct mls_range *r;
- if (!selinux_mls_enabled)
+ if (!policydb.mls_enabled)
return 0;
switch (specified) {
@@ -559,7 +559,7 @@ int mls_compute_sid(struct context *scon
void mls_export_netlbl_lvl(struct context *context,
struct netlbl_lsm_secattr *secattr)
{
- if (!selinux_mls_enabled)
+ if (!policydb.mls_enabled)
return;
secattr->attr.mls.lvl = context->range.level[0].sens - 1;
@@ -579,7 +579,7 @@ void mls_export_netlbl_lvl(struct contex
void mls_import_netlbl_lvl(struct context *context,
struct netlbl_lsm_secattr *secattr)
{
- if (!selinux_mls_enabled)
+ if (!policydb.mls_enabled)
return;
context->range.level[0].sens = secattr->attr.mls.lvl + 1;
@@ -601,7 +601,7 @@ int mls_export_netlbl_cat(struct context
{
int rc;
- if (!selinux_mls_enabled)
+ if (!policydb.mls_enabled)
return 0;
rc = ebitmap_netlbl_export(&context->range.level[0].cat,
@@ -629,7 +629,7 @@ int mls_import_netlbl_cat(struct context
{
int rc;
- if (!selinux_mls_enabled)
+ if (!policydb.mls_enabled)
return 0;
rc = ebitmap_netlbl_import(&context->range.level[0].cat,
diff -pruN security-testing-2.6/security/selinux/ss/mls.h security-testing-2.6-new/security/selinux/ss/mls.h
--- security-testing-2.6/security/selinux/ss/mls.h 2010-01-29 01:06:42.168051431 +0100
+++ security-testing-2.6-new/security/selinux/ss/mls.h 2010-02-01 23:17:31.025223083 +0100
@@ -39,6 +39,8 @@ int mls_context_to_sid(struct policydb *
int mls_from_string(char *str, struct context *context, gfp_t gfp_mask);
+int mls_range_set(struct context *context, struct mls_range *range);
+
int mls_convert_context(struct policydb *oldp,
struct policydb *newp,
struct context *context);
diff -pruN security-testing-2.6/security/selinux/ss/mls_types.h security-testing-2.6-new/security/selinux/ss/mls_types.h
--- security-testing-2.6/security/selinux/ss/mls_types.h 2010-01-29 01:06:42.168051431 +0100
+++ security-testing-2.6-new/security/selinux/ss/mls_types.h 2010-02-01 22:23:11.799224771 +0100
@@ -15,6 +15,7 @@
#define _SS_MLS_TYPES_H_
#include "security.h"
+#include "ebitmap.h"
struct mls_level {
u32 sens; /* sensitivity */
@@ -27,7 +28,7 @@ struct mls_range {
static inline int mls_level_eq(struct mls_level *l1, struct mls_level *l2)
{
- if (!selinux_mls_enabled)
+ if (!security_mls_enabled())
return 1;
return ((l1->sens == l2->sens) &&
@@ -36,7 +37,7 @@ static inline int mls_level_eq(struct ml
static inline int mls_level_dom(struct mls_level *l1, struct mls_level *l2)
{
- if (!selinux_mls_enabled)
+ if (!security_mls_enabled())
return 1;
return ((l1->sens >= l2->sens) &&
diff -pruN security-testing-2.6/security/selinux/ss/policydb.c security-testing-2.6-new/security/selinux/ss/policydb.c
--- security-testing-2.6/security/selinux/ss/policydb.c 2010-01-29 02:02:47.740046077 +0100
+++ security-testing-2.6-new/security/selinux/ss/policydb.c 2010-02-01 22:12:18.601226073 +0100
@@ -52,8 +52,6 @@ static char *symtab_name[SYM_NUM] = {
};
#endif
-int selinux_mls_enabled;
-
static unsigned int symtab_sizes[SYM_NUM] = {
2,
32,
@@ -455,7 +453,7 @@ static int policydb_index_others(struct
printk(KERN_DEBUG "SELinux: %d users, %d roles, %d types, %d bools",
p->p_users.nprim, p->p_roles.nprim, p->p_types.nprim, p->p_bools.nprim);
- if (selinux_mls_enabled)
+ if (p->mls_enabled)
printk(", %d sens, %d cats", p->p_levels.nprim,
p->p_cats.nprim);
printk("n");
@@ -1717,14 +1715,12 @@ int policydb_read(struct policydb *p, vo
int i, j, rc;
__le32 buf[4];
u32 nodebuf[8];
- u32 len, len2, config, nprim, nel, nel2;
+ u32 len, len2, nprim, nel, nel2;
char *policydb_str;
struct policydb_compat_info *info;
struct range_trans *rt;
struct mls_range *r;
- config = 0;
-
rc = policydb_init(p);
if (rc)
goto out;
@@ -1772,7 +1768,7 @@ int policydb_read(struct policydb *p, vo
kfree(policydb_str);
policydb_str = NULL;
- /* Read the version, config, and table sizes. */
+ /* Read the version and table sizes. */
rc = next_entry(buf, fp, sizeof(u32)*4);
if (rc < 0)
goto bad;
@@ -1787,13 +1783,7 @@ int policydb_read(struct policydb *p, vo
}
if ((le32_to_cpu(buf[1]) & POLICYDB_CONFIG_MLS)) {
- if (ss_initialized && !selinux_mls_enabled) {
- printk(KERN_ERR "SELinux: Cannot switch between non-MLS"
- " and MLS policiesn");
- goto bad;
- }
- selinux_mls_enabled = 1;
- config |= POLICYDB_CONFIG_MLS;
+ p->mls_enabled = 1;
if (p->policyvers < POLICYDB_VERSION_MLS) {
printk(KERN_ERR "SELinux: security policydb version %d "
@@ -1801,12 +1791,6 @@ int policydb_read(struct policydb *p, vo
p->policyvers);
goto bad;
}
- } else {
- if (ss_initialized && selinux_mls_enabled) {
- printk(KERN_ERR "SELinux: Cannot switch between MLS and"
- " non-MLS policiesn");
- goto bad;
- }
}
p->reject_unknown = !!(le32_to_cpu(buf[1]) & REJECT_UNKNOWN);
p->allow_unknown = !!(le32_to_cpu(buf[1]) & ALLOW_UNKNOWN);
diff -pruN security-testing-2.6/security/selinux/ss/policydb.h security-testing-2.6-new/security/selinux/ss/policydb.h
--- security-testing-2.6/security/selinux/ss/policydb.h 2010-01-29 02:02:47.740046077 +0100
+++ security-testing-2.6-new/security/selinux/ss/policydb.h 2010-02-01 20:47:08.352232380 +0100
@@ -27,6 +27,8 @@
#include "symtab.h"
#include "avtab.h"
#include "sidtab.h"
+#include "ebitmap.h"
+#include "mls_types.h"
#include "context.h"
#include "constraint.h"
@@ -185,6 +187,8 @@ struct genfs {
/* The policy database */
struct policydb {
+ int mls_enabled;
+
/* symbol tables */
struct symtab symtab[SYM_NUM];
#define p_commons symtab[SYM_COMMONS]
diff -pruN security-testing-2.6/security/selinux/ss/services.c security-testing-2.6-new/security/selinux/ss/services.c
--- security-testing-2.6/security/selinux/ss/services.c 2010-01-29 02:02:47.742042805 +0100
+++ security-testing-2.6-new/security/selinux/ss/services.c 2010-02-01 23:28:02.338227931 +0100
@@ -26,6 +26,10 @@
*
* Added support for bounds domain and audit messaged on masked permissions
*
+ * Updated: Guido Trentalancia <guido@xxxxxxxxxxxxxxxx>
+ *
+ * Added support for runtime switching of the policy type
+ *
* Copyright (C) 2008, 2009 NEC Corporation
* Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
* Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
@@ -232,6 +236,16 @@ static void map_decision(u16 tclass, str
}
}
+/*
+ * Returns a boolean value.
+ * True: if the specified policy is MLS or MCS
+ * False: if the specified policy is a standard policy
+ * without MLS/MCS support
+ */
+int security_mls_enabled(void)
+{
+ return policydb.mls_enabled;
+}
/*
* Return the boolean value of a constraint expression
@@ -1547,6 +1561,8 @@ static int convert_context(u32 key,
{
struct convert_context_args *args;
struct context oldc;
+ struct ocontext *oc;
+ struct mls_range *range;
struct role_datum *role;
struct type_datum *typdatum;
struct user_datum *usrdatum;
@@ -1614,9 +1630,43 @@ static int convert_context(u32 key,
goto bad;
c->type = typdatum->value;
- rc = mls_convert_context(args->oldp, args->newp, c);
- if (rc)
- goto bad;
+ /* Convert the MLS/MCS fields if dealing with MLS/MCS policies */
+ if (args->oldp->mls_enabled
+ && args->newp->mls_enabled) {
+ rc = mls_convert_context(args->oldp, args->newp, c);
+ if (rc)
+ goto bad;
+ }
+
+ /*
+ * Switching between MLS/MCS and non-MLS/non-MCS policy:
+ * free any storage used by the MLS fields in the
+ * context for all existing entries in the sidtab.
+ */
+ if (args->oldp->mls_enabled && !args->newp->mls_enabled)
+ mls_context_destroy(c);
+
+ /*
+ * Switching between non-MLS/non-MCS and MLS/MCS policy:
+ * ensure that the MLS fields of the context for all
+ * existing entries in the sidtab are filled in with a
+ * suitable default value, likely taken from one of the
+ * initial SIDs.
+ */
+ if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
+ oc = args->newp->ocontexts[OCON_ISID];
+ while (oc && oc->sid[0] != SECINITSID_UNLABELED)
+ oc = oc->next;
+ if (!oc) {
+ printk(KERN_ERR "SELinux: unable to look up"
+ " the initial SIDs listn");
+ goto bad;
+ }
+ range = &oc->context[0].range;
+ rc = mls_range_set(c, range);
+ if (rc)
+ goto bad;
+ }
/* Check the validity of the new context. */
if (!policydb_context_isvalid(args->newp, c)) {
@@ -1712,6 +1762,14 @@ int security_load_policy(void *data, siz
if (policydb_read(&newpolicydb, fp))
return -EINVAL;
+ /* If switching between different policy types, log it */
+ if (policydb.mls_enabled && !newpolicydb.mls_enabled)
+ printk(KERN_INFO "SELinux: Switching between MLS/MCS"
+ " and standard policy...n");
+ else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
+ printk(KERN_INFO "SELinux: Switching between standard"
+ " and MLS/MCS policy...n");
+
if (sidtab_init(&newsidtab)) {
policydb_destroy(&newpolicydb);
return -ENOMEM;
@@ -1741,8 +1799,12 @@ int security_load_policy(void *data, siz
args.oldp = &policydb;
args.newp = &newpolicydb;
rc = sidtab_map(&newsidtab, convert_context, &args);
- if (rc)
+ if (rc) {
+ printk(KERN_ERR "SELinux: unable to convert the internal"
+ " representation of contexts in the new SID"
+ " tablen");
goto err;
+ }
/* Save the old policydb and SID table to free later. */
memcpy(&oldpolicydb, &policydb, sizeof policydb);
@@ -2338,7 +2400,7 @@ int security_sid_mls_copy(u32 sid, u32 m
u32 len;
int rc = 0;
- if (!ss_initialized || !selinux_mls_enabled) {
+ if (!ss_initialized || !policydb.mls_enabled) {
*new_sid = sid;
goto out;
}
@@ -2439,7 +2501,7 @@ int security_net_peersid_resolve(u32 nlb
/* we don't need to check ss_initialized here since the only way both
* nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
* security server was initialized and ss_initialized was true */
- if (!selinux_mls_enabled) {
+ if (!policydb.mls_enabled) {
*peer_sid = SECSID_NULL;
return 0;
}
Attachment:
switch-policy.patch
Description: Binary data
