diff options
Diffstat (limited to 'security/selinux/ss/services.c')
-rw-r--r-- | security/selinux/ss/services.c | 562 |
1 files changed, 291 insertions, 271 deletions
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index ff17820d35e..d6bb20cbad6 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -65,16 +65,10 @@ #include "audit.h" extern void selnl_notify_policyload(u32 seqno); -unsigned int policydb_loaded_version; int selinux_policycap_netpeer; int selinux_policycap_openperm; -/* - * This is declared in avc.c - */ -extern const struct selinux_class_perm selinux_class_perm; - static DEFINE_RWLOCK(policy_rwlock); static struct sidtab sidtab; @@ -98,6 +92,165 @@ static int context_struct_compute_av(struct context *scontext, u16 tclass, u32 requested, struct av_decision *avd); + +struct selinux_mapping { + u16 value; /* policy value */ + unsigned num_perms; + u32 perms[sizeof(u32) * 8]; +}; + +static struct selinux_mapping *current_mapping; +static u16 current_mapping_size; + +static int selinux_set_mapping(struct policydb *pol, + struct security_class_mapping *map, + struct selinux_mapping **out_map_p, + u16 *out_map_size) +{ + struct selinux_mapping *out_map = NULL; + size_t size = sizeof(struct selinux_mapping); + u16 i, j; + unsigned k; + bool print_unknown_handle = false; + + /* Find number of classes in the input mapping */ + if (!map) + return -EINVAL; + i = 0; + while (map[i].name) + i++; + + /* Allocate space for the class records, plus one for class zero */ + out_map = kcalloc(++i, size, GFP_ATOMIC); + if (!out_map) + return -ENOMEM; + + /* Store the raw class and permission values */ + j = 0; + while (map[j].name) { + struct security_class_mapping *p_in = map + (j++); + struct selinux_mapping *p_out = out_map + j; + + /* An empty class string skips ahead */ + if (!strcmp(p_in->name, "")) { + p_out->num_perms = 0; + continue; + } + + p_out->value = string_to_security_class(pol, p_in->name); + if (!p_out->value) { + printk(KERN_INFO + "SELinux: Class %s not defined in policy.\n", + p_in->name); + if (pol->reject_unknown) + goto err; + p_out->num_perms = 0; + print_unknown_handle = true; + continue; + } + + k = 0; + while (p_in->perms && p_in->perms[k]) { + /* An empty permission string skips ahead */ + if (!*p_in->perms[k]) { + k++; + continue; + } + p_out->perms[k] = string_to_av_perm(pol, p_out->value, + p_in->perms[k]); + if (!p_out->perms[k]) { + printk(KERN_INFO + "SELinux: Permission %s in class %s not defined in policy.\n", + p_in->perms[k], p_in->name); + if (pol->reject_unknown) + goto err; + print_unknown_handle = true; + } + + k++; + } + p_out->num_perms = k; + } + + if (print_unknown_handle) + printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n", + pol->allow_unknown ? "allowed" : "denied"); + + *out_map_p = out_map; + *out_map_size = i; + return 0; +err: + kfree(out_map); + return -EINVAL; +} + +/* + * Get real, policy values from mapped values + */ + +static u16 unmap_class(u16 tclass) +{ + if (tclass < current_mapping_size) + return current_mapping[tclass].value; + + return tclass; +} + +static u32 unmap_perm(u16 tclass, u32 tperm) +{ + if (tclass < current_mapping_size) { + unsigned i; + u32 kperm = 0; + + for (i = 0; i < current_mapping[tclass].num_perms; i++) + if (tperm & (1<<i)) { + kperm |= current_mapping[tclass].perms[i]; + tperm &= ~(1<<i); + } + return kperm; + } + + return tperm; +} + +static void map_decision(u16 tclass, struct av_decision *avd, + int allow_unknown) +{ + if (tclass < current_mapping_size) { + unsigned i, n = current_mapping[tclass].num_perms; + u32 result; + + for (i = 0, result = 0; i < n; i++) { + if (avd->allowed & current_mapping[tclass].perms[i]) + result |= 1<<i; + if (allow_unknown && !current_mapping[tclass].perms[i]) + result |= 1<<i; + } + avd->allowed = result; + + for (i = 0, result = 0; i < n; i++) + if (avd->auditallow & current_mapping[tclass].perms[i]) + result |= 1<<i; + avd->auditallow = result; + + for (i = 0, result = 0; i < n; i++) { + if (avd->auditdeny & current_mapping[tclass].perms[i]) + result |= 1<<i; + if (!allow_unknown && !current_mapping[tclass].perms[i]) + result |= 1<<i; + } + /* + * In case the kernel has a bug and requests a permission + * between num_perms and the maximum permission number, we + * should audit that denial + */ + for (; i < (sizeof(u32)*8); i++) + result |= 1<<i; + avd->auditdeny = result; + } +} + + /* * Return the boolean value of a constraint expression * when it is applied to the specified source and target @@ -467,21 +620,9 @@ static int context_struct_compute_av(struct context *scontext, struct class_datum *tclass_datum; struct ebitmap *sattr, *tattr; struct ebitmap_node *snode, *tnode; - const struct selinux_class_perm *kdefs = &selinux_class_perm; unsigned int i, j; /* - * Remap extended Netlink classes for old policy versions. - * Do this here rather than socket_type_to_security_class() - * in case a newer policy version is loaded, allowing sockets - * to remain in the correct class. - */ - if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS) - if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET && - tclass <= SECCLASS_NETLINK_DNRT_SOCKET) - tclass = SECCLASS_NETLINK_SOCKET; - - /* * Initialize the access vectors to the default values. */ avd->allowed = 0; @@ -490,33 +631,11 @@ static int context_struct_compute_av(struct context *scontext, avd->seqno = latest_granting; avd->flags = 0; - /* - * Check for all the invalid cases. - * - tclass 0 - * - tclass > policy and > kernel - * - tclass > policy but is a userspace class - * - tclass > policy but we do not allow unknowns - */ - if (unlikely(!tclass)) - goto inval_class; - if (unlikely(tclass > policydb.p_classes.nprim)) - if (tclass > kdefs->cts_len || - !kdefs->class_to_string[tclass] || - !policydb.allow_unknown) - goto inval_class; - - /* - * Kernel class and we allow unknown so pad the allow decision - * the pad will be all 1 for unknown classes. - */ - if (tclass <= kdefs->cts_len && policydb.allow_unknown) - avd->allowed = policydb.undefined_perms[tclass - 1]; - - /* - * Not in policy. Since decision is completed (all 1 or all 0) return. - */ - if (unlikely(tclass > policydb.p_classes.nprim)) - return 0; + if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) { + if (printk_ratelimit()) + printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass); + return -EINVAL; + } tclass_datum = policydb.class_val_to_struct[tclass - 1]; @@ -568,8 +687,8 @@ static int context_struct_compute_av(struct context *scontext, * role is changing, then check the (current_role, new_role) * pair. */ - if (tclass == SECCLASS_PROCESS && - (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) && + if (tclass == policydb.process_class && + (avd->allowed & policydb.process_trans_perms) && scontext->role != tcontext->role) { for (ra = policydb.role_allow; ra; ra = ra->next) { if (scontext->role == ra->role && @@ -577,8 +696,7 @@ static int context_struct_compute_av(struct context *scontext, break; } if (!ra) - avd->allowed &= ~(PROCESS__TRANSITION | - PROCESS__DYNTRANSITION); + avd->allowed &= ~policydb.process_trans_perms; } /* @@ -590,21 +708,6 @@ static int context_struct_compute_av(struct context *scontext, tclass, requested, avd); return 0; - -inval_class: - if (!tclass || tclass > kdefs->cts_len || - !kdefs->class_to_string[tclass]) { - if (printk_ratelimit()) - printk(KERN_ERR "SELinux: %s: unrecognized class %d\n", - __func__, tclass); - return -EINVAL; - } - - /* - * Known to the kernel, but not to the policy. - * Handle as a denial (allowed is 0). - */ - return 0; } static int security_validtrans_handle_fail(struct context *ocontext, @@ -636,13 +739,14 @@ out: } int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid, - u16 tclass) + u16 orig_tclass) { struct context *ocontext; struct context *ncontext; struct context *tcontext; struct class_datum *tclass_datum; struct constraint_node *constraint; + u16 tclass; int rc = 0; if (!ss_initialized) @@ -650,16 +754,7 @@ int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid, read_lock(&policy_rwlock); - /* - * Remap extended Netlink classes for old policy versions. - * Do this here rather than socket_type_to_security_class() - * in case a newer policy version is loaded, allowing sockets - * to remain in the correct class. - */ - if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS) - if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET && - tclass <= SECCLASS_NETLINK_DNRT_SOCKET) - tclass = SECCLASS_NETLINK_SOCKET; + tclass = unmap_class(orig_tclass); if (!tclass || tclass > policydb.p_classes.nprim) { printk(KERN_ERR "SELinux: %s: unrecognized class %d\n", @@ -792,6 +887,38 @@ out: } +static int security_compute_av_core(u32 ssid, + u32 tsid, + u16 tclass, + u32 requested, + struct av_decision *avd) +{ + struct context *scontext = NULL, *tcontext = NULL; + int rc = 0; + + scontext = sidtab_search(&sidtab, ssid); + if (!scontext) { + printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", + __func__, ssid); + return -EINVAL; + } + tcontext = sidtab_search(&sidtab, tsid); + if (!tcontext) { + printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", + __func__, tsid); + return -EINVAL; + } + + rc = context_struct_compute_av(scontext, tcontext, tclass, + requested, avd); + + /* permissive domain? */ + if (ebitmap_get_bit(&policydb.permissive_map, scontext->type)) + avd->flags |= AVD_FLAGS_PERMISSIVE; + + return rc; +} + /** * security_compute_av - Compute access vector decisions. * @ssid: source security identifier @@ -807,12 +934,49 @@ out: */ int security_compute_av(u32 ssid, u32 tsid, - u16 tclass, - u32 requested, + u16 orig_tclass, + u32 orig_requested, struct av_decision *avd) { - struct context *scontext = NULL, *tcontext = NULL; - int rc = 0; + u16 tclass; + u32 requested; + int rc; + + read_lock(&policy_rwlock); + + if (!ss_initialized) + goto allow; + + requested = unmap_perm(orig_tclass, orig_requested); + tclass = unmap_class(orig_tclass); + if (unlikely(orig_tclass && !tclass)) { + if (policydb.allow_unknown) + goto allow; + rc = -EINVAL; + goto out; + } + rc = security_compute_av_core(ssid, tsid, tclass, requested, avd); + map_decision(orig_tclass, avd, policydb.allow_unknown); +out: + read_unlock(&policy_rwlock); + return rc; +allow: + avd->allowed = 0xffffffff; + avd->auditallow = 0; + avd->auditdeny = 0xffffffff; + avd->seqno = latest_granting; + avd->flags = 0; + rc = 0; + goto out; +} + +int security_compute_av_user(u32 ssid, + u32 tsid, + u16 tclass, + u32 requested, + struct av_decision *avd) +{ + int rc; if (!ss_initialized) { avd->allowed = 0xffffffff; @@ -823,29 +987,7 @@ int security_compute_av(u32 ssid, } read_lock(&policy_rwlock); - - scontext = sidtab_search(&sidtab, ssid); - if (!scontext) { - printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", - __func__, ssid); - rc = -EINVAL; - goto out; - } - tcontext = sidtab_search(&sidtab, tsid); - if (!tcontext) { - printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", - __func__, tsid); - rc = -EINVAL; - goto out; - } - - rc = context_struct_compute_av(scontext, tcontext, tclass, - requested, avd); - - /* permissive domain? */ - if (ebitmap_get_bit(&policydb.permissive_map, scontext->type)) - avd->flags |= AVD_FLAGS_PERMISSIVE; -out: + rc = security_compute_av_core(ssid, tsid, tclass, requested, avd); read_unlock(&policy_rwlock); return rc; } @@ -1204,20 +1346,22 @@ out: static int security_compute_sid(u32 ssid, u32 tsid, - u16 tclass, + u16 orig_tclass, u32 specified, - u32 *out_sid) + u32 *out_sid, + bool kern) { struct context *scontext = NULL, *tcontext = NULL, newcontext; struct role_trans *roletr = NULL; struct avtab_key avkey; struct avtab_datum *avdatum; struct avtab_node *node; + u16 tclass; int rc = 0; if (!ss_initialized) { - switch (tclass) { - case SECCLASS_PROCESS: + switch (orig_tclass) { + case SECCLASS_PROCESS: /* kernel value */ *out_sid = ssid; break; default: @@ -1231,6 +1375,11 @@ static int security_compute_sid(u32 ssid, read_lock(&policy_rwlock); + if (kern) + tclass = unmap_class(orig_tclass); + else + tclass = orig_tclass; + scontext = sidtab_search(&sidtab, ssid); if (!scontext) { printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", @@ -1260,13 +1409,11 @@ static int security_compute_sid(u32 ssid, } /* Set the role and type to default values. */ - switch (tclass) { - case SECCLASS_PROCESS: + if (tclass == policydb.process_class) { /* Use the current role and type of process. */ newcontext.role = scontext->role; newcontext.type = scontext->type; - break; - default: + } else { /* Use the well-defined object role. */ newcontext.role = OBJECT_R_VAL; /* Use the type of the related object. */ @@ -1297,8 +1444,7 @@ static int security_compute_sid(u32 ssid, } /* Check for class-specific changes. */ - switch (tclass) { - case SECCLASS_PROCESS: + if (tclass == policydb.process_class) { if (specified & AVTAB_TRANSITION) { /* Look for a role transition rule. */ for (roletr = policydb.role_tr; roletr; @@ -1311,9 +1457,6 @@ static int security_compute_sid(u32 ssid, } } } - break; - default: - break; } /* Set the MLS attributes. @@ -1358,7 +1501,17 @@ int security_transition_sid(u32 ssid, u16 tclass, u32 *out_sid) { - return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid); + return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, + out_sid, true); +} + +int security_transition_sid_user(u32 ssid, + u32 tsid, + u16 tclass, + u32 *out_sid) +{ + return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, + out_sid, false); } /** @@ -1379,7 +1532,8 @@ int security_member_sid(u32 ssid, u16 tclass, u32 *out_sid) { - return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid); + return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid, + false); } /** @@ -1400,144 +1554,8 @@ int security_change_sid(u32 ssid, u16 tclass, u32 *out_sid) { - return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid); -} - -/* - * Verify that each kernel class that is defined in the - * policy is correct - */ -static int validate_classes(struct policydb *p) -{ - int i, j; - struct class_datum *cladatum; - struct perm_datum *perdatum; - u32 nprim, tmp, common_pts_len, perm_val, pol_val; - u16 class_val; - const struct selinux_class_perm *kdefs = &selinux_class_perm; - const char *def_class, *def_perm, *pol_class; - struct symtab *perms; - bool print_unknown_handle = 0; - - if (p->allow_unknown) { - u32 num_classes = kdefs->cts_len; - p->undefined_perms = kcalloc(num_classes, sizeof(u32), GFP_KERNEL); - if (!p->undefined_perms) - return -ENOMEM; - } - - for (i = 1; i < kdefs->cts_len; i++) { - def_class = kdefs->class_to_string[i]; - if (!def_class) - continue; - if (i > p->p_classes.nprim) { - printk(KERN_INFO - "SELinux: class %s not defined in policy\n", - def_class); - if (p->reject_unknown) - return -EINVAL; - if (p->allow_unknown) - p->undefined_perms[i-1] = ~0U; - print_unknown_handle = 1; - continue; - } - pol_class = p->p_class_val_to_name[i-1]; - if (strcmp(pol_class, def_class)) { - printk(KERN_ERR - "SELinux: class %d is incorrect, found %s but should be %s\n", - i, pol_class, def_class); - return -EINVAL; - } - } - for (i = 0; i < kdefs->av_pts_len; i++) { - class_val = kdefs->av_perm_to_string[i].tclass; - perm_val = kdefs->av_perm_to_string[i].value; - def_perm = kdefs->av_perm_to_string[i].name; - if (class_val > p->p_classes.nprim) - continue; - pol_class = p->p_class_val_to_name[class_val-1]; - cladatum = hashtab_search(p->p_classes.table, pol_class); - BUG_ON(!cladatum); - perms = &cladatum->permissions; - nprim = 1 << (perms->nprim - 1); - if (perm_val > nprim) { - printk(KERN_INFO - "SELinux: permission %s in class %s not defined in policy\n", - def_perm, pol_class); - if (p->reject_unknown) - return -EINVAL; - if (p->allow_unknown) - p->undefined_perms[class_val-1] |= perm_val; - print_unknown_handle = 1; - continue; - } - perdatum = hashtab_search(perms->table, def_perm); - if (perdatum == NULL) { - printk(KERN_ERR - "SELinux: permission %s in class %s not found in policy, bad policy\n", - def_perm, pol_class); - return -EINVAL; - } - pol_val = 1 << (perdatum->value - 1); - if (pol_val != perm_val) { - printk(KERN_ERR - "SELinux: permission %s in class %s has incorrect value\n", - def_perm, pol_class); - return -EINVAL; - } - } - for (i = 0; i < kdefs->av_inherit_len; i++) { - class_val = kdefs->av_inherit[i].tclass; - if (class_val > p->p_classes.nprim) - continue; - pol_class = p->p_class_val_to_name[class_val-1]; - cladatum = hashtab_search(p->p_classes.table, pol_class); - BUG_ON(!cladatum); - if (!cladatum->comdatum) { - printk(KERN_ERR - "SELinux: class %s should have an inherits clause but does not\n", - pol_class); - return -EINVAL; - } - tmp = kdefs->av_inherit[i].common_base; - common_pts_len = 0; - while (!(tmp & 0x01)) { - common_pts_len++; - tmp >>= 1; - } - perms = &cladatum->comdatum->permissions; - for (j = 0; j < common_pts_len; j++) { - def_perm = kdefs->av_inherit[i].common_pts[j]; - if (j >= perms->nprim) { - printk(KERN_INFO - "SELinux: permission %s in class %s not defined in policy\n", - def_perm, pol_class); - if (p->reject_unknown) - return -EINVAL; - if (p->allow_unknown) - p->undefined_perms[class_val-1] |= (1 << j); - print_unknown_handle = 1; - continue; - } - perdatum = hashtab_search(perms->table, def_perm); - if (perdatum == NULL) { - printk(KERN_ERR - "SELinux: permission %s in class %s not found in policy, bad policy\n", - def_perm, pol_class); - return -EINVAL; - } - if (perdatum->value != j + 1) { - printk(KERN_ERR - "SELinux: permission %s in class %s has incorrect value\n", - def_perm, pol_class); - return -EINVAL; - } - } - } - if (print_unknown_handle) - printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n", - (security_get_allow_unknown() ? "allowed" : "denied")); - return 0; + return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid, + false); } /* Clone the SID into the new SID table. */ @@ -1710,8 +1728,10 @@ int security_load_policy(void *data, size_t len) { struct policydb oldpolicydb, newpolicydb; struct sidtab oldsidtab, newsidtab; + struct selinux_mapping *oldmap, *map = NULL; struct convert_context_args args; u32 seqno; + u16 map_size; int rc = 0; struct policy_file file = { data, len }, *fp = &file; @@ -1721,22 +1741,19 @@ int security_load_policy(void *data, size_t len) avtab_cache_destroy(); return -EINVAL; } - if (policydb_load_isids(&policydb, &sidtab)) { + if (selinux_set_mapping(&policydb, secclass_map, + ¤t_mapping, + ¤t_mapping_size)) { policydb_destroy(&policydb); avtab_cache_destroy(); return -EINVAL; } - /* Verify that the kernel defined classes are correct. */ - if (validate_classes(&policydb)) { - printk(KERN_ERR - "SELinux: the definition of a class is incorrect\n"); - sidtab_destroy(&sidtab); + if (policydb_load_isids(&policydb, &sidtab)) { policydb_destroy(&policydb); avtab_cache_destroy(); return -EINVAL; } security_load_policycaps(); - policydb_loaded_version = policydb.policyvers; ss_initialized = 1; seqno = ++latest_granting; selinux_complete_init(); @@ -1759,13 +1776,9 @@ int security_load_policy(void *data, size_t len) return -ENOMEM; } - /* Verify that the kernel defined classes are correct. */ - if (validate_classes(&newpolicydb)) { - printk(KERN_ERR - "SELinux: the definition of a class is incorrect\n"); - rc = -EINVAL; + if (selinux_set_mapping(&newpolicydb, secclass_map, + &map, &map_size)) goto err; - } rc = security_preserve_bools(&newpolicydb); if (rc) { @@ -1799,13 +1812,16 @@ int security_load_policy(void *data, size_t len) memcpy(&policydb, &newpolicydb, sizeof policydb); sidtab_set(&sidtab, &newsidtab); security_load_policycaps(); + oldmap = current_mapping; + current_mapping = map; + current_mapping_size = map_size; seqno = ++latest_granting; - policydb_loaded_version = policydb.policyvers; write_unlock_irq(&policy_rwlock); /* Free the old policydb and SID table. */ policydb_destroy(&oldpolicydb); sidtab_destroy(&oldsidtab); + kfree(oldmap); avc_ss_reset(seqno); selnl_notify_policyload(seqno); @@ -1815,6 +1831,7 @@ int security_load_policy(void *data, size_t len) return 0; err: + kfree(map); sidtab_destroy(&newsidtab); policydb_destroy(&newpolicydb); return rc; @@ -2091,7 +2108,7 @@ out_unlock: } for (i = 0, j = 0; i < mynel; i++) { rc = avc_has_perm_noaudit(fromsid, mysids[i], - SECCLASS_PROCESS, + SECCLASS_PROCESS, /* kernel value */ PROCESS__TRANSITION, AVC_STRICT, NULL); if (!rc) @@ -2119,10 +2136,11 @@ out: */ int security_genfs_sid(const char *fstype, char *path, - u16 sclass, + u16 orig_sclass, u32 *sid) { int len; + u16 sclass; struct genfs *genfs; struct ocontext *c; int rc = 0, cmp = 0; @@ -2132,6 +2150,8 @@ int security_genfs_sid(const char *fstype, read_lock(&policy_rwlock); + sclass = unmap_class(orig_sclass); + for (genfs = policydb.genfs; genfs; genfs = genfs->next) { cmp = strcmp(fstype, genfs->fstype); if (cmp <= 0) |