kernel-aes67/security/selinux/ss/policydb.h
Stephen Smalley 45e5421eb5 SELinux: add more validity checks on policy load
Add more validity checks at policy load time to reject malformed
policies and prevent subsequent out-of-range indexing when in permissive
mode.  Resolves the NULL pointer dereference reported in
https://bugzilla.redhat.com/show_bug.cgi?id=357541.

Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2007-11-08 08:56:23 +11:00

291 lines
7.9 KiB
C

/*
* A policy database (policydb) specifies the
* configuration data for the security policy.
*
* Author : Stephen Smalley, <sds@epoch.ncsc.mil>
*/
/*
* Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
*
* Support for enhanced MLS infrastructure.
*
* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
*
* Added conditional policy language extensions
*
* Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
* Copyright (C) 2003 - 2004 Tresys Technology, LLC
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 2.
*/
#ifndef _SS_POLICYDB_H_
#define _SS_POLICYDB_H_
#include "symtab.h"
#include "avtab.h"
#include "sidtab.h"
#include "context.h"
#include "constraint.h"
/*
* A datum type is defined for each kind of symbol
* in the configuration data: individual permissions,
* common prefixes for access vectors, classes,
* users, roles, types, sensitivities, categories, etc.
*/
/* Permission attributes */
struct perm_datum {
u32 value; /* permission bit + 1 */
};
/* Attributes of a common prefix for access vectors */
struct common_datum {
u32 value; /* internal common value */
struct symtab permissions; /* common permissions */
};
/* Class attributes */
struct class_datum {
u32 value; /* class value */
char *comkey; /* common name */
struct common_datum *comdatum; /* common datum */
struct symtab permissions; /* class-specific permission symbol table */
struct constraint_node *constraints; /* constraints on class permissions */
struct constraint_node *validatetrans; /* special transition rules */
};
/* Role attributes */
struct role_datum {
u32 value; /* internal role value */
struct ebitmap dominates; /* set of roles dominated by this role */
struct ebitmap types; /* set of authorized types for role */
};
struct role_trans {
u32 role; /* current role */
u32 type; /* program executable type */
u32 new_role; /* new role */
struct role_trans *next;
};
struct role_allow {
u32 role; /* current role */
u32 new_role; /* new role */
struct role_allow *next;
};
/* Type attributes */
struct type_datum {
u32 value; /* internal type value */
unsigned char primary; /* primary name? */
};
/* User attributes */
struct user_datum {
u32 value; /* internal user value */
struct ebitmap roles; /* set of authorized roles for user */
struct mls_range range; /* MLS range (min - max) for user */
struct mls_level dfltlevel; /* default login MLS level for user */
};
/* Sensitivity attributes */
struct level_datum {
struct mls_level *level; /* sensitivity and associated categories */
unsigned char isalias; /* is this sensitivity an alias for another? */
};
/* Category attributes */
struct cat_datum {
u32 value; /* internal category bit + 1 */
unsigned char isalias; /* is this category an alias for another? */
};
struct range_trans {
u32 source_type;
u32 target_type;
u32 target_class;
struct mls_range target_range;
struct range_trans *next;
};
/* Boolean data type */
struct cond_bool_datum {
__u32 value; /* internal type value */
int state;
};
struct cond_node;
/*
* The configuration data includes security contexts for
* initial SIDs, unlabeled file systems, TCP and UDP port numbers,
* network interfaces, and nodes. This structure stores the
* relevant data for one such entry. Entries of the same kind
* (e.g. all initial SIDs) are linked together into a list.
*/
struct ocontext {
union {
char *name; /* name of initial SID, fs, netif, fstype, path */
struct {
u8 protocol;
u16 low_port;
u16 high_port;
} port; /* TCP or UDP port information */
struct {
u32 addr;
u32 mask;
} node; /* node information */
struct {
u32 addr[4];
u32 mask[4];
} node6; /* IPv6 node information */
} u;
union {
u32 sclass; /* security class for genfs */
u32 behavior; /* labeling behavior for fs_use */
} v;
struct context context[2]; /* security context(s) */
u32 sid[2]; /* SID(s) */
struct ocontext *next;
};
struct genfs {
char *fstype;
struct ocontext *head;
struct genfs *next;
};
/* symbol table array indices */
#define SYM_COMMONS 0
#define SYM_CLASSES 1
#define SYM_ROLES 2
#define SYM_TYPES 3
#define SYM_USERS 4
#define SYM_BOOLS 5
#define SYM_LEVELS 6
#define SYM_CATS 7
#define SYM_NUM 8
/* object context array indices */
#define OCON_ISID 0 /* initial SIDs */
#define OCON_FS 1 /* unlabeled file systems */
#define OCON_PORT 2 /* TCP and UDP port numbers */
#define OCON_NETIF 3 /* network interfaces */
#define OCON_NODE 4 /* nodes */
#define OCON_FSUSE 5 /* fs_use */
#define OCON_NODE6 6 /* IPv6 nodes */
#define OCON_NUM 7
/* The policy database */
struct policydb {
/* symbol tables */
struct symtab symtab[SYM_NUM];
#define p_commons symtab[SYM_COMMONS]
#define p_classes symtab[SYM_CLASSES]
#define p_roles symtab[SYM_ROLES]
#define p_types symtab[SYM_TYPES]
#define p_users symtab[SYM_USERS]
#define p_bools symtab[SYM_BOOLS]
#define p_levels symtab[SYM_LEVELS]
#define p_cats symtab[SYM_CATS]
/* symbol names indexed by (value - 1) */
char **sym_val_to_name[SYM_NUM];
#define p_common_val_to_name sym_val_to_name[SYM_COMMONS]
#define p_class_val_to_name sym_val_to_name[SYM_CLASSES]
#define p_role_val_to_name sym_val_to_name[SYM_ROLES]
#define p_type_val_to_name sym_val_to_name[SYM_TYPES]
#define p_user_val_to_name sym_val_to_name[SYM_USERS]
#define p_bool_val_to_name sym_val_to_name[SYM_BOOLS]
#define p_sens_val_to_name sym_val_to_name[SYM_LEVELS]
#define p_cat_val_to_name sym_val_to_name[SYM_CATS]
/* class, role, and user attributes indexed by (value - 1) */
struct class_datum **class_val_to_struct;
struct role_datum **role_val_to_struct;
struct user_datum **user_val_to_struct;
/* type enforcement access vectors and transitions */
struct avtab te_avtab;
/* role transitions */
struct role_trans *role_tr;
/* bools indexed by (value - 1) */
struct cond_bool_datum **bool_val_to_struct;
/* type enforcement conditional access vectors and transitions */
struct avtab te_cond_avtab;
/* linked list indexing te_cond_avtab by conditional */
struct cond_node* cond_list;
/* role allows */
struct role_allow *role_allow;
/* security contexts of initial SIDs, unlabeled file systems,
TCP or UDP port numbers, network interfaces and nodes */
struct ocontext *ocontexts[OCON_NUM];
/* security contexts for files in filesystems that cannot support
a persistent label mapping or use another
fixed labeling behavior. */
struct genfs *genfs;
/* range transitions */
struct range_trans *range_tr;
/* type -> attribute reverse mapping */
struct ebitmap *type_attr_map;
unsigned int policyvers;
unsigned int reject_unknown : 1;
unsigned int allow_unknown : 1;
u32 *undefined_perms;
};
extern void policydb_destroy(struct policydb *p);
extern int policydb_load_isids(struct policydb *p, struct sidtab *s);
extern int policydb_context_isvalid(struct policydb *p, struct context *c);
extern int policydb_class_isvalid(struct policydb *p, unsigned int class);
extern int policydb_type_isvalid(struct policydb *p, unsigned int type);
extern int policydb_role_isvalid(struct policydb *p, unsigned int role);
extern int policydb_read(struct policydb *p, void *fp);
#define PERM_SYMTAB_SIZE 32
#define POLICYDB_CONFIG_MLS 1
/* the config flags related to unknown classes/perms are bits 2 and 3 */
#define REJECT_UNKNOWN 0x00000002
#define ALLOW_UNKNOWN 0x00000004
#define OBJECT_R "object_r"
#define OBJECT_R_VAL 1
#define POLICYDB_MAGIC SELINUX_MAGIC
#define POLICYDB_STRING "SE Linux"
struct policy_file {
char *data;
size_t len;
};
static inline int next_entry(void *buf, struct policy_file *fp, size_t bytes)
{
if (bytes > fp->len)
return -EINVAL;
memcpy(buf, fp->data, bytes);
fp->data += bytes;
fp->len -= bytes;
return 0;
}
#endif /* _SS_POLICYDB_H_ */