linux/security/dummy.c

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/*
* Stub functions for the default security function pointers in case no
* security model is loaded.
*
* Copyright (C) 2001 WireX Communications, Inc <chris@wirex.com>
* Copyright (C) 2001-2002 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2001 Networks Associates Technology, Inc <ssmalley@nai.com>
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*/
#undef DEBUG
#include <linux/capability.h>
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/mman.h>
#include <linux/pagemap.h>
#include <linux/swap.h>
#include <linux/security.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <net/sock.h>
#include <linux/xattr.h>
#include <linux/hugetlb.h>
#include <linux/ptrace.h>
#include <linux/file.h>
static int dummy_ptrace (struct task_struct *parent, struct task_struct *child)
{
return 0;
}
static int dummy_capget (struct task_struct *target, kernel_cap_t * effective,
kernel_cap_t * inheritable, kernel_cap_t * permitted)
{
*effective = *inheritable = *permitted = 0;
if (!issecure(SECURE_NOROOT)) {
if (target->euid == 0) {
*permitted |= (~0 & ~CAP_FS_MASK);
*effective |= (~0 & ~CAP_TO_MASK(CAP_SETPCAP) & ~CAP_FS_MASK);
}
if (target->fsuid == 0) {
*permitted |= CAP_FS_MASK;
*effective |= CAP_FS_MASK;
}
}
return 0;
}
static int dummy_capset_check (struct task_struct *target,
kernel_cap_t * effective,
kernel_cap_t * inheritable,
kernel_cap_t * permitted)
{
return -EPERM;
}
static void dummy_capset_set (struct task_struct *target,
kernel_cap_t * effective,
kernel_cap_t * inheritable,
kernel_cap_t * permitted)
{
return;
}
static int dummy_acct (struct file *file)
{
return 0;
}
static int dummy_capable (struct task_struct *tsk, int cap)
{
if (cap_raised (tsk->cap_effective, cap))
return 0;
return -EPERM;
}
static int dummy_sysctl (ctl_table * table, int op)
{
return 0;
}
static int dummy_quotactl (int cmds, int type, int id, struct super_block *sb)
{
return 0;
}
static int dummy_quota_on (struct dentry *dentry)
{
return 0;
}
static int dummy_syslog (int type)
{
if ((type != 3 && type != 10) && current->euid)
return -EPERM;
return 0;
}
static int dummy_settime(struct timespec *ts, struct timezone *tz)
{
if (!capable(CAP_SYS_TIME))
return -EPERM;
return 0;
}
static int dummy_vm_enough_memory(long pages)
{
int cap_sys_admin = 0;
if (dummy_capable(current, CAP_SYS_ADMIN) == 0)
cap_sys_admin = 1;
return __vm_enough_memory(pages, cap_sys_admin);
}
static int dummy_bprm_alloc_security (struct linux_binprm *bprm)
{
return 0;
}
static void dummy_bprm_free_security (struct linux_binprm *bprm)
{
return;
}
static void dummy_bprm_apply_creds (struct linux_binprm *bprm, int unsafe)
{
if (bprm->e_uid != current->uid || bprm->e_gid != current->gid) {
[PATCH] setuid core dump Add a new `suid_dumpable' sysctl: This value can be used to query and set the core dump mode for setuid or otherwise protected/tainted binaries. The modes are 0 - (default) - traditional behaviour. Any process which has changed privilege levels or is execute only will not be dumped 1 - (debug) - all processes dump core when possible. The core dump is owned by the current user and no security is applied. This is intended for system debugging situations only. Ptrace is unchecked. 2 - (suidsafe) - any binary which normally would not be dumped is dumped readable by root only. This allows the end user to remove such a dump but not access it directly. For security reasons core dumps in this mode will not overwrite one another or other files. This mode is appropriate when adminstrators are attempting to debug problems in a normal environment. (akpm: > > +EXPORT_SYMBOL(suid_dumpable); > > EXPORT_SYMBOL_GPL? No problem to me. > > if (current->euid == current->uid && current->egid == current->gid) > > current->mm->dumpable = 1; > > Should this be SUID_DUMP_USER? Actually the feedback I had from last time was that the SUID_ defines should go because its clearer to follow the numbers. They can go everywhere (and there are lots of places where dumpable is tested/used as a bool in untouched code) > Maybe this should be renamed to `dump_policy' or something. Doing that > would help us catch any code which isn't using the #defines, too. Fair comment. The patch was designed to be easy to maintain for Red Hat rather than for merging. Changing that field would create a gigantic diff because it is used all over the place. ) Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 07:09:43 +00:00
current->mm->dumpable = suid_dumpable;
if ((unsafe & ~LSM_UNSAFE_PTRACE_CAP) && !capable(CAP_SETUID)) {
bprm->e_uid = current->uid;
bprm->e_gid = current->gid;
}
}
current->suid = current->euid = current->fsuid = bprm->e_uid;
current->sgid = current->egid = current->fsgid = bprm->e_gid;
dummy_capget(current, &current->cap_effective, &current->cap_inheritable, &current->cap_permitted);
}
static void dummy_bprm_post_apply_creds (struct linux_binprm *bprm)
{
return;
}
static int dummy_bprm_set_security (struct linux_binprm *bprm)
{
return 0;
}
static int dummy_bprm_check_security (struct linux_binprm *bprm)
{
return 0;
}
static int dummy_bprm_secureexec (struct linux_binprm *bprm)
{
/* The new userland will simply use the value provided
in the AT_SECURE field to decide whether secure mode
is required. Hence, this logic is required to preserve
the legacy decision algorithm used by the old userland. */
return (current->euid != current->uid ||
current->egid != current->gid);
}
static int dummy_sb_alloc_security (struct super_block *sb)
{
return 0;
}
static void dummy_sb_free_security (struct super_block *sb)
{
return;
}
static int dummy_sb_copy_data (struct file_system_type *type,
void *orig, void *copy)
{
return 0;
}
static int dummy_sb_kern_mount (struct super_block *sb, void *data)
{
return 0;
}
static int dummy_sb_statfs (struct super_block *sb)
{
return 0;
}
static int dummy_sb_mount (char *dev_name, struct nameidata *nd, char *type,
unsigned long flags, void *data)
{
return 0;
}
static int dummy_sb_check_sb (struct vfsmount *mnt, struct nameidata *nd)
{
return 0;
}
static int dummy_sb_umount (struct vfsmount *mnt, int flags)
{
return 0;
}
static void dummy_sb_umount_close (struct vfsmount *mnt)
{
return;
}
static void dummy_sb_umount_busy (struct vfsmount *mnt)
{
return;
}
static void dummy_sb_post_remount (struct vfsmount *mnt, unsigned long flags,
void *data)
{
return;
}
static void dummy_sb_post_mountroot (void)
{
return;
}
static void dummy_sb_post_addmount (struct vfsmount *mnt, struct nameidata *nd)
{
return;
}
static int dummy_sb_pivotroot (struct nameidata *old_nd, struct nameidata *new_nd)
{
return 0;
}
static void dummy_sb_post_pivotroot (struct nameidata *old_nd, struct nameidata *new_nd)
{
return;
}
static int dummy_inode_alloc_security (struct inode *inode)
{
return 0;
}
static void dummy_inode_free_security (struct inode *inode)
{
return;
}
[PATCH] security: enable atomic inode security labeling The following patch set enables atomic security labeling of newly created inodes by altering the fs code to invoke a new LSM hook to obtain the security attribute to apply to a newly created inode and to set up the incore inode security state during the inode creation transaction. This parallels the existing processing for setting ACLs on newly created inodes. Otherwise, it is possible for new inodes to be accessed by another thread via the dcache prior to complete security setup (presently handled by the post_create/mkdir/... LSM hooks in the VFS) and a newly created inode may be left unlabeled on the disk in the event of a crash. SELinux presently works around the issue by ensuring that the incore inode security label is initialized to a special SID that is inaccessible to unprivileged processes (in accordance with policy), thereby preventing inappropriate access but potentially causing false denials on legitimate accesses. A simple test program demonstrates such false denials on SELinux, and the patch solves the problem. Similar such false denials have been encountered in real applications. This patch defines a new inode_init_security LSM hook to obtain the security attribute to apply to a newly created inode and to set up the incore inode security state for it, and adds a corresponding hook function implementation to SELinux. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09 20:01:35 +00:00
static int dummy_inode_init_security (struct inode *inode, struct inode *dir,
char **name, void **value, size_t *len)
{
return -EOPNOTSUPP;
}
static int dummy_inode_create (struct inode *inode, struct dentry *dentry,
int mask)
{
return 0;
}
static int dummy_inode_link (struct dentry *old_dentry, struct inode *inode,
struct dentry *new_dentry)
{
return 0;
}
static int dummy_inode_unlink (struct inode *inode, struct dentry *dentry)
{
return 0;
}
static int dummy_inode_symlink (struct inode *inode, struct dentry *dentry,
const char *name)
{
return 0;
}
static int dummy_inode_mkdir (struct inode *inode, struct dentry *dentry,
int mask)
{
return 0;
}
static int dummy_inode_rmdir (struct inode *inode, struct dentry *dentry)
{
return 0;
}
static int dummy_inode_mknod (struct inode *inode, struct dentry *dentry,
int mode, dev_t dev)
{
return 0;
}
static int dummy_inode_rename (struct inode *old_inode,
struct dentry *old_dentry,
struct inode *new_inode,
struct dentry *new_dentry)
{
return 0;
}
static int dummy_inode_readlink (struct dentry *dentry)
{
return 0;
}
static int dummy_inode_follow_link (struct dentry *dentry,
struct nameidata *nameidata)
{
return 0;
}
static int dummy_inode_permission (struct inode *inode, int mask, struct nameidata *nd)
{
return 0;
}
static int dummy_inode_setattr (struct dentry *dentry, struct iattr *iattr)
{
return 0;
}
static int dummy_inode_getattr (struct vfsmount *mnt, struct dentry *dentry)
{
return 0;
}
static void dummy_inode_delete (struct inode *ino)
{
return;
}
static int dummy_inode_setxattr (struct dentry *dentry, char *name, void *value,
size_t size, int flags)
{
if (!strncmp(name, XATTR_SECURITY_PREFIX,
sizeof(XATTR_SECURITY_PREFIX) - 1) &&
!capable(CAP_SYS_ADMIN))
return -EPERM;
return 0;
}
static void dummy_inode_post_setxattr (struct dentry *dentry, char *name, void *value,
size_t size, int flags)
{
}
static int dummy_inode_getxattr (struct dentry *dentry, char *name)
{
return 0;
}
static int dummy_inode_listxattr (struct dentry *dentry)
{
return 0;
}
static int dummy_inode_removexattr (struct dentry *dentry, char *name)
{
if (!strncmp(name, XATTR_SECURITY_PREFIX,
sizeof(XATTR_SECURITY_PREFIX) - 1) &&
!capable(CAP_SYS_ADMIN))
return -EPERM;
return 0;
}
static int dummy_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err)
{
return -EOPNOTSUPP;
}
static int dummy_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags)
{
return -EOPNOTSUPP;
}
static int dummy_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
{
return 0;
}
static const char *dummy_inode_xattr_getsuffix(void)
{
return NULL;
}
static int dummy_file_permission (struct file *file, int mask)
{
return 0;
}
static int dummy_file_alloc_security (struct file *file)
{
return 0;
}
static void dummy_file_free_security (struct file *file)
{
return;
}
static int dummy_file_ioctl (struct file *file, unsigned int command,
unsigned long arg)
{
return 0;
}
static int dummy_file_mmap (struct file *file, unsigned long reqprot,
unsigned long prot,
unsigned long flags)
{
return 0;
}
static int dummy_file_mprotect (struct vm_area_struct *vma,
unsigned long reqprot,
unsigned long prot)
{
return 0;
}
static int dummy_file_lock (struct file *file, unsigned int cmd)
{
return 0;
}
static int dummy_file_fcntl (struct file *file, unsigned int cmd,
unsigned long arg)
{
return 0;
}
static int dummy_file_set_fowner (struct file *file)
{
return 0;
}
static int dummy_file_send_sigiotask (struct task_struct *tsk,
struct fown_struct *fown, int sig)
{
return 0;
}
static int dummy_file_receive (struct file *file)
{
return 0;
}
static int dummy_task_create (unsigned long clone_flags)
{
return 0;
}
static int dummy_task_alloc_security (struct task_struct *p)
{
return 0;
}
static void dummy_task_free_security (struct task_struct *p)
{
return;
}
static int dummy_task_setuid (uid_t id0, uid_t id1, uid_t id2, int flags)
{
return 0;
}
static int dummy_task_post_setuid (uid_t id0, uid_t id1, uid_t id2, int flags)
{
dummy_capget(current, &current->cap_effective, &current->cap_inheritable, &current->cap_permitted);
return 0;
}
static int dummy_task_setgid (gid_t id0, gid_t id1, gid_t id2, int flags)
{
return 0;
}
static int dummy_task_setpgid (struct task_struct *p, pid_t pgid)
{
return 0;
}
static int dummy_task_getpgid (struct task_struct *p)
{
return 0;
}
static int dummy_task_getsid (struct task_struct *p)
{
return 0;
}
static int dummy_task_setgroups (struct group_info *group_info)
{
return 0;
}
static int dummy_task_setnice (struct task_struct *p, int nice)
{
return 0;
}
static int dummy_task_setrlimit (unsigned int resource, struct rlimit *new_rlim)
{
return 0;
}
static int dummy_task_setscheduler (struct task_struct *p, int policy,
struct sched_param *lp)
{
return 0;
}
static int dummy_task_getscheduler (struct task_struct *p)
{
return 0;
}
static int dummy_task_wait (struct task_struct *p)
{
return 0;
}
static int dummy_task_kill (struct task_struct *p, struct siginfo *info,
int sig)
{
return 0;
}
static int dummy_task_prctl (int option, unsigned long arg2, unsigned long arg3,
unsigned long arg4, unsigned long arg5)
{
return 0;
}
static void dummy_task_reparent_to_init (struct task_struct *p)
{
p->euid = p->fsuid = 0;
return;
}
static void dummy_task_to_inode(struct task_struct *p, struct inode *inode)
{ }
static int dummy_ipc_permission (struct kern_ipc_perm *ipcp, short flag)
{
return 0;
}
static int dummy_ipc_getsecurity(struct kern_ipc_perm *ipcp, void *buffer, size_t size)
{
return -EOPNOTSUPP;
}
static int dummy_msg_msg_alloc_security (struct msg_msg *msg)
{
return 0;
}
static void dummy_msg_msg_free_security (struct msg_msg *msg)
{
return;
}
static int dummy_msg_queue_alloc_security (struct msg_queue *msq)
{
return 0;
}
static void dummy_msg_queue_free_security (struct msg_queue *msq)
{
return;
}
static int dummy_msg_queue_associate (struct msg_queue *msq,
int msqflg)
{
return 0;
}
static int dummy_msg_queue_msgctl (struct msg_queue *msq, int cmd)
{
return 0;
}
static int dummy_msg_queue_msgsnd (struct msg_queue *msq, struct msg_msg *msg,
int msgflg)
{
return 0;
}
static int dummy_msg_queue_msgrcv (struct msg_queue *msq, struct msg_msg *msg,
struct task_struct *target, long type,
int mode)
{
return 0;
}
static int dummy_shm_alloc_security (struct shmid_kernel *shp)
{
return 0;
}
static void dummy_shm_free_security (struct shmid_kernel *shp)
{
return;
}
static int dummy_shm_associate (struct shmid_kernel *shp, int shmflg)
{
return 0;
}
static int dummy_shm_shmctl (struct shmid_kernel *shp, int cmd)
{
return 0;
}
static int dummy_shm_shmat (struct shmid_kernel *shp, char __user *shmaddr,
int shmflg)
{
return 0;
}
static int dummy_sem_alloc_security (struct sem_array *sma)
{
return 0;
}
static void dummy_sem_free_security (struct sem_array *sma)
{
return;
}
static int dummy_sem_associate (struct sem_array *sma, int semflg)
{
return 0;
}
static int dummy_sem_semctl (struct sem_array *sma, int cmd)
{
return 0;
}
static int dummy_sem_semop (struct sem_array *sma,
struct sembuf *sops, unsigned nsops, int alter)
{
return 0;
}
static int dummy_netlink_send (struct sock *sk, struct sk_buff *skb)
{
NETLINK_CB(skb).eff_cap = current->cap_effective;
return 0;
}
static int dummy_netlink_recv (struct sk_buff *skb)
{
if (!cap_raised (NETLINK_CB (skb).eff_cap, CAP_NET_ADMIN))
return -EPERM;
return 0;
}
#ifdef CONFIG_SECURITY_NETWORK
static int dummy_unix_stream_connect (struct socket *sock,
struct socket *other,
struct sock *newsk)
{
return 0;
}
static int dummy_unix_may_send (struct socket *sock,
struct socket *other)
{
return 0;
}
static int dummy_socket_create (int family, int type,
int protocol, int kern)
{
return 0;
}
static void dummy_socket_post_create (struct socket *sock, int family, int type,
int protocol, int kern)
{
return;
}
static int dummy_socket_bind (struct socket *sock, struct sockaddr *address,
int addrlen)
{
return 0;
}
static int dummy_socket_connect (struct socket *sock, struct sockaddr *address,
int addrlen)
{
return 0;
}
static int dummy_socket_listen (struct socket *sock, int backlog)
{
return 0;
}
static int dummy_socket_accept (struct socket *sock, struct socket *newsock)
{
return 0;
}
static void dummy_socket_post_accept (struct socket *sock,
struct socket *newsock)
{
return;
}
static int dummy_socket_sendmsg (struct socket *sock, struct msghdr *msg,
int size)
{
return 0;
}
static int dummy_socket_recvmsg (struct socket *sock, struct msghdr *msg,
int size, int flags)
{
return 0;
}
static int dummy_socket_getsockname (struct socket *sock)
{
return 0;
}
static int dummy_socket_getpeername (struct socket *sock)
{
return 0;
}
static int dummy_socket_setsockopt (struct socket *sock, int level, int optname)
{
return 0;
}
static int dummy_socket_getsockopt (struct socket *sock, int level, int optname)
{
return 0;
}
static int dummy_socket_shutdown (struct socket *sock, int how)
{
return 0;
}
static int dummy_socket_sock_rcv_skb (struct sock *sk, struct sk_buff *skb)
{
return 0;
}
[SECURITY]: TCP/UDP getpeersec This patch implements an application of the LSM-IPSec networking controls whereby an application can determine the label of the security association its TCP or UDP sockets are currently connected to via getsockopt and the auxiliary data mechanism of recvmsg. Patch purpose: This patch enables a security-aware application to retrieve the security context of an IPSec security association a particular TCP or UDP socket is using. The application can then use this security context to determine the security context for processing on behalf of the peer at the other end of this connection. In the case of UDP, the security context is for each individual packet. An example application is the inetd daemon, which could be modified to start daemons running at security contexts dependent on the remote client. Patch design approach: - Design for TCP The patch enables the SELinux LSM to set the peer security context for a socket based on the security context of the IPSec security association. The application may retrieve this context using getsockopt. When called, the kernel determines if the socket is a connected (TCP_ESTABLISHED) TCP socket and, if so, uses the dst_entry cache on the socket to retrieve the security associations. If a security association has a security context, the context string is returned, as for UNIX domain sockets. - Design for UDP Unlike TCP, UDP is connectionless. This requires a somewhat different API to retrieve the peer security context. With TCP, the peer security context stays the same throughout the connection, thus it can be retrieved at any time between when the connection is established and when it is torn down. With UDP, each read/write can have different peer and thus the security context might change every time. As a result the security context retrieval must be done TOGETHER with the packet retrieval. The solution is to build upon the existing Unix domain socket API for retrieving user credentials. Linux offers the API for obtaining user credentials via ancillary messages (i.e., out of band/control messages that are bundled together with a normal message). Patch implementation details: - Implementation for TCP The security context can be retrieved by applications using getsockopt with the existing SO_PEERSEC flag. As an example (ignoring error checking): getsockopt(sockfd, SOL_SOCKET, SO_PEERSEC, optbuf, &optlen); printf("Socket peer context is: %s\n", optbuf); The SELinux function, selinux_socket_getpeersec, is extended to check for labeled security associations for connected (TCP_ESTABLISHED == sk->sk_state) TCP sockets only. If so, the socket has a dst_cache of struct dst_entry values that may refer to security associations. If these have security associations with security contexts, the security context is returned. getsockopt returns a buffer that contains a security context string or the buffer is unmodified. - Implementation for UDP To retrieve the security context, the application first indicates to the kernel such desire by setting the IP_PASSSEC option via getsockopt. Then the application retrieves the security context using the auxiliary data mechanism. An example server application for UDP should look like this: toggle = 1; toggle_len = sizeof(toggle); setsockopt(sockfd, SOL_IP, IP_PASSSEC, &toggle, &toggle_len); recvmsg(sockfd, &msg_hdr, 0); if (msg_hdr.msg_controllen > sizeof(struct cmsghdr)) { cmsg_hdr = CMSG_FIRSTHDR(&msg_hdr); if (cmsg_hdr->cmsg_len <= CMSG_LEN(sizeof(scontext)) && cmsg_hdr->cmsg_level == SOL_IP && cmsg_hdr->cmsg_type == SCM_SECURITY) { memcpy(&scontext, CMSG_DATA(cmsg_hdr), sizeof(scontext)); } } ip_setsockopt is enhanced with a new socket option IP_PASSSEC to allow a server socket to receive security context of the peer. A new ancillary message type SCM_SECURITY. When the packet is received we get the security context from the sec_path pointer which is contained in the sk_buff, and copy it to the ancillary message space. An additional LSM hook, selinux_socket_getpeersec_udp, is defined to retrieve the security context from the SELinux space. The existing function, selinux_socket_getpeersec does not suit our purpose, because the security context is copied directly to user space, rather than to kernel space. Testing: We have tested the patch by setting up TCP and UDP connections between applications on two machines using the IPSec policies that result in labeled security associations being built. For TCP, we can then extract the peer security context using getsockopt on either end. For UDP, the receiving end can retrieve the security context using the auxiliary data mechanism of recvmsg. Signed-off-by: Catherine Zhang <cxzhang@watson.ibm.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-21 06:41:23 +00:00
static int dummy_socket_getpeersec_stream(struct socket *sock, char __user *optval,
int __user *optlen, unsigned len)
{
return -ENOPROTOOPT;
}
static int dummy_socket_getpeersec_dgram(struct sk_buff *skb, char **secdata,
u32 *seclen)
{
return -ENOPROTOOPT;
}
static inline int dummy_sk_alloc_security (struct sock *sk, int family, gfp_t priority)
{
return 0;
}
static inline void dummy_sk_free_security (struct sock *sk)
{
}
[LSM-IPSec]: Security association restriction. This patch series implements per packet access control via the extension of the Linux Security Modules (LSM) interface by hooks in the XFRM and pfkey subsystems that leverage IPSec security associations to label packets. Extensions to the SELinux LSM are included that leverage the patch for this purpose. This patch implements the changes necessary to the XFRM subsystem, pfkey interface, ipv4/ipv6, and xfrm_user interface to restrict a socket to use only authorized security associations (or no security association) to send/receive network packets. Patch purpose: The patch is designed to enable access control per packets based on the strongly authenticated IPSec security association. Such access controls augment the existing ones based on network interface and IP address. The former are very coarse-grained, and the latter can be spoofed. By using IPSec, the system can control access to remote hosts based on cryptographic keys generated using the IPSec mechanism. This enables access control on a per-machine basis or per-application if the remote machine is running the same mechanism and trusted to enforce the access control policy. Patch design approach: The overall approach is that policy (xfrm_policy) entries set by user-level programs (e.g., setkey for ipsec-tools) are extended with a security context that is used at policy selection time in the XFRM subsystem to restrict the sockets that can send/receive packets via security associations (xfrm_states) that are built from those policies. A presentation available at www.selinux-symposium.org/2005/presentations/session2/2-3-jaeger.pdf from the SELinux symposium describes the overall approach. Patch implementation details: On output, the policy retrieved (via xfrm_policy_lookup or xfrm_sk_policy_lookup) must be authorized for the security context of the socket and the same security context is required for resultant security association (retrieved or negotiated via racoon in ipsec-tools). This is enforced in xfrm_state_find. On input, the policy retrieved must also be authorized for the socket (at __xfrm_policy_check), and the security context of the policy must also match the security association being used. The patch has virtually no impact on packets that do not use IPSec. The existing Netfilter (outgoing) and LSM rcv_skb hooks are used as before. Also, if IPSec is used without security contexts, the impact is minimal. The LSM must allow such policies to be selected for the combination of socket and remote machine, but subsequent IPSec processing proceeds as in the original case. Testing: The pfkey interface is tested using the ipsec-tools. ipsec-tools have been modified (a separate ipsec-tools patch is available for version 0.5) that supports assignment of xfrm_policy entries and security associations with security contexts via setkey and the negotiation using the security contexts via racoon. The xfrm_user interface is tested via ad hoc programs that set security contexts. These programs are also available from me, and contain programs for setting, getting, and deleting policy for testing this interface. Testing of sa functions was done by tracing kernel behavior. Signed-off-by: Trent Jaeger <tjaeger@cse.psu.edu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-12-14 07:12:27 +00:00
static unsigned int dummy_sk_getsid(struct sock *sk, struct flowi *fl, u8 dir)
{
return 0;
}
#endif /* CONFIG_SECURITY_NETWORK */
[LSM-IPSec]: Security association restriction. This patch series implements per packet access control via the extension of the Linux Security Modules (LSM) interface by hooks in the XFRM and pfkey subsystems that leverage IPSec security associations to label packets. Extensions to the SELinux LSM are included that leverage the patch for this purpose. This patch implements the changes necessary to the XFRM subsystem, pfkey interface, ipv4/ipv6, and xfrm_user interface to restrict a socket to use only authorized security associations (or no security association) to send/receive network packets. Patch purpose: The patch is designed to enable access control per packets based on the strongly authenticated IPSec security association. Such access controls augment the existing ones based on network interface and IP address. The former are very coarse-grained, and the latter can be spoofed. By using IPSec, the system can control access to remote hosts based on cryptographic keys generated using the IPSec mechanism. This enables access control on a per-machine basis or per-application if the remote machine is running the same mechanism and trusted to enforce the access control policy. Patch design approach: The overall approach is that policy (xfrm_policy) entries set by user-level programs (e.g., setkey for ipsec-tools) are extended with a security context that is used at policy selection time in the XFRM subsystem to restrict the sockets that can send/receive packets via security associations (xfrm_states) that are built from those policies. A presentation available at www.selinux-symposium.org/2005/presentations/session2/2-3-jaeger.pdf from the SELinux symposium describes the overall approach. Patch implementation details: On output, the policy retrieved (via xfrm_policy_lookup or xfrm_sk_policy_lookup) must be authorized for the security context of the socket and the same security context is required for resultant security association (retrieved or negotiated via racoon in ipsec-tools). This is enforced in xfrm_state_find. On input, the policy retrieved must also be authorized for the socket (at __xfrm_policy_check), and the security context of the policy must also match the security association being used. The patch has virtually no impact on packets that do not use IPSec. The existing Netfilter (outgoing) and LSM rcv_skb hooks are used as before. Also, if IPSec is used without security contexts, the impact is minimal. The LSM must allow such policies to be selected for the combination of socket and remote machine, but subsequent IPSec processing proceeds as in the original case. Testing: The pfkey interface is tested using the ipsec-tools. ipsec-tools have been modified (a separate ipsec-tools patch is available for version 0.5) that supports assignment of xfrm_policy entries and security associations with security contexts via setkey and the negotiation using the security contexts via racoon. The xfrm_user interface is tested via ad hoc programs that set security contexts. These programs are also available from me, and contain programs for setting, getting, and deleting policy for testing this interface. Testing of sa functions was done by tracing kernel behavior. Signed-off-by: Trent Jaeger <tjaeger@cse.psu.edu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-12-14 07:12:27 +00:00
#ifdef CONFIG_SECURITY_NETWORK_XFRM
static int dummy_xfrm_policy_alloc_security(struct xfrm_policy *xp, struct xfrm_user_sec_ctx *sec_ctx)
{
return 0;
}
static inline int dummy_xfrm_policy_clone_security(struct xfrm_policy *old, struct xfrm_policy *new)
{
return 0;
}
static void dummy_xfrm_policy_free_security(struct xfrm_policy *xp)
{
}
static int dummy_xfrm_state_alloc_security(struct xfrm_state *x, struct xfrm_user_sec_ctx *sec_ctx)
{
return 0;
}
static void dummy_xfrm_state_free_security(struct xfrm_state *x)
{
}
static int dummy_xfrm_policy_lookup(struct xfrm_policy *xp, u32 sk_sid, u8 dir)
{
return 0;
}
#endif /* CONFIG_SECURITY_NETWORK_XFRM */
static int dummy_register_security (const char *name, struct security_operations *ops)
{
return -EINVAL;
}
static int dummy_unregister_security (const char *name, struct security_operations *ops)
{
return -EINVAL;
}
static void dummy_d_instantiate (struct dentry *dentry, struct inode *inode)
{
return;
}
static int dummy_getprocattr(struct task_struct *p, char *name, void *value, size_t size)
{
return -EINVAL;
}
static int dummy_setprocattr(struct task_struct *p, char *name, void *value, size_t size)
{
return -EINVAL;
}
#ifdef CONFIG_KEYS
static inline int dummy_key_alloc(struct key *key)
{
return 0;
}
static inline void dummy_key_free(struct key *key)
{
}
static inline int dummy_key_permission(key_ref_t key_ref,
struct task_struct *context,
key_perm_t perm)
{
return 0;
}
#endif /* CONFIG_KEYS */
struct security_operations dummy_security_ops;
#define set_to_dummy_if_null(ops, function) \
do { \
if (!ops->function) { \
ops->function = dummy_##function; \
pr_debug("Had to override the " #function \
" security operation with the dummy one.\n");\
} \
} while (0)
void security_fixup_ops (struct security_operations *ops)
{
set_to_dummy_if_null(ops, ptrace);
set_to_dummy_if_null(ops, capget);
set_to_dummy_if_null(ops, capset_check);
set_to_dummy_if_null(ops, capset_set);
set_to_dummy_if_null(ops, acct);
set_to_dummy_if_null(ops, capable);
set_to_dummy_if_null(ops, quotactl);
set_to_dummy_if_null(ops, quota_on);
set_to_dummy_if_null(ops, sysctl);
set_to_dummy_if_null(ops, syslog);
set_to_dummy_if_null(ops, settime);
set_to_dummy_if_null(ops, vm_enough_memory);
set_to_dummy_if_null(ops, bprm_alloc_security);
set_to_dummy_if_null(ops, bprm_free_security);
set_to_dummy_if_null(ops, bprm_apply_creds);
set_to_dummy_if_null(ops, bprm_post_apply_creds);
set_to_dummy_if_null(ops, bprm_set_security);
set_to_dummy_if_null(ops, bprm_check_security);
set_to_dummy_if_null(ops, bprm_secureexec);
set_to_dummy_if_null(ops, sb_alloc_security);
set_to_dummy_if_null(ops, sb_free_security);
set_to_dummy_if_null(ops, sb_copy_data);
set_to_dummy_if_null(ops, sb_kern_mount);
set_to_dummy_if_null(ops, sb_statfs);
set_to_dummy_if_null(ops, sb_mount);
set_to_dummy_if_null(ops, sb_check_sb);
set_to_dummy_if_null(ops, sb_umount);
set_to_dummy_if_null(ops, sb_umount_close);
set_to_dummy_if_null(ops, sb_umount_busy);
set_to_dummy_if_null(ops, sb_post_remount);
set_to_dummy_if_null(ops, sb_post_mountroot);
set_to_dummy_if_null(ops, sb_post_addmount);
set_to_dummy_if_null(ops, sb_pivotroot);
set_to_dummy_if_null(ops, sb_post_pivotroot);
set_to_dummy_if_null(ops, inode_alloc_security);
set_to_dummy_if_null(ops, inode_free_security);
[PATCH] security: enable atomic inode security labeling The following patch set enables atomic security labeling of newly created inodes by altering the fs code to invoke a new LSM hook to obtain the security attribute to apply to a newly created inode and to set up the incore inode security state during the inode creation transaction. This parallels the existing processing for setting ACLs on newly created inodes. Otherwise, it is possible for new inodes to be accessed by another thread via the dcache prior to complete security setup (presently handled by the post_create/mkdir/... LSM hooks in the VFS) and a newly created inode may be left unlabeled on the disk in the event of a crash. SELinux presently works around the issue by ensuring that the incore inode security label is initialized to a special SID that is inaccessible to unprivileged processes (in accordance with policy), thereby preventing inappropriate access but potentially causing false denials on legitimate accesses. A simple test program demonstrates such false denials on SELinux, and the patch solves the problem. Similar such false denials have been encountered in real applications. This patch defines a new inode_init_security LSM hook to obtain the security attribute to apply to a newly created inode and to set up the incore inode security state for it, and adds a corresponding hook function implementation to SELinux. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09 20:01:35 +00:00
set_to_dummy_if_null(ops, inode_init_security);
set_to_dummy_if_null(ops, inode_create);
set_to_dummy_if_null(ops, inode_link);
set_to_dummy_if_null(ops, inode_unlink);
set_to_dummy_if_null(ops, inode_symlink);
set_to_dummy_if_null(ops, inode_mkdir);
set_to_dummy_if_null(ops, inode_rmdir);
set_to_dummy_if_null(ops, inode_mknod);
set_to_dummy_if_null(ops, inode_rename);
set_to_dummy_if_null(ops, inode_readlink);
set_to_dummy_if_null(ops, inode_follow_link);
set_to_dummy_if_null(ops, inode_permission);
set_to_dummy_if_null(ops, inode_setattr);
set_to_dummy_if_null(ops, inode_getattr);
set_to_dummy_if_null(ops, inode_delete);
set_to_dummy_if_null(ops, inode_setxattr);
set_to_dummy_if_null(ops, inode_post_setxattr);
set_to_dummy_if_null(ops, inode_getxattr);
set_to_dummy_if_null(ops, inode_listxattr);
set_to_dummy_if_null(ops, inode_removexattr);
set_to_dummy_if_null(ops, inode_xattr_getsuffix);
set_to_dummy_if_null(ops, inode_getsecurity);
set_to_dummy_if_null(ops, inode_setsecurity);
set_to_dummy_if_null(ops, inode_listsecurity);
set_to_dummy_if_null(ops, file_permission);
set_to_dummy_if_null(ops, file_alloc_security);
set_to_dummy_if_null(ops, file_free_security);
set_to_dummy_if_null(ops, file_ioctl);
set_to_dummy_if_null(ops, file_mmap);
set_to_dummy_if_null(ops, file_mprotect);
set_to_dummy_if_null(ops, file_lock);
set_to_dummy_if_null(ops, file_fcntl);
set_to_dummy_if_null(ops, file_set_fowner);
set_to_dummy_if_null(ops, file_send_sigiotask);
set_to_dummy_if_null(ops, file_receive);
set_to_dummy_if_null(ops, task_create);
set_to_dummy_if_null(ops, task_alloc_security);
set_to_dummy_if_null(ops, task_free_security);
set_to_dummy_if_null(ops, task_setuid);
set_to_dummy_if_null(ops, task_post_setuid);
set_to_dummy_if_null(ops, task_setgid);
set_to_dummy_if_null(ops, task_setpgid);
set_to_dummy_if_null(ops, task_getpgid);
set_to_dummy_if_null(ops, task_getsid);
set_to_dummy_if_null(ops, task_setgroups);
set_to_dummy_if_null(ops, task_setnice);
set_to_dummy_if_null(ops, task_setrlimit);
set_to_dummy_if_null(ops, task_setscheduler);
set_to_dummy_if_null(ops, task_getscheduler);
set_to_dummy_if_null(ops, task_wait);
set_to_dummy_if_null(ops, task_kill);
set_to_dummy_if_null(ops, task_prctl);
set_to_dummy_if_null(ops, task_reparent_to_init);
set_to_dummy_if_null(ops, task_to_inode);
set_to_dummy_if_null(ops, ipc_permission);
set_to_dummy_if_null(ops, ipc_getsecurity);
set_to_dummy_if_null(ops, msg_msg_alloc_security);
set_to_dummy_if_null(ops, msg_msg_free_security);
set_to_dummy_if_null(ops, msg_queue_alloc_security);
set_to_dummy_if_null(ops, msg_queue_free_security);
set_to_dummy_if_null(ops, msg_queue_associate);
set_to_dummy_if_null(ops, msg_queue_msgctl);
set_to_dummy_if_null(ops, msg_queue_msgsnd);
set_to_dummy_if_null(ops, msg_queue_msgrcv);
set_to_dummy_if_null(ops, shm_alloc_security);
set_to_dummy_if_null(ops, shm_free_security);
set_to_dummy_if_null(ops, shm_associate);
set_to_dummy_if_null(ops, shm_shmctl);
set_to_dummy_if_null(ops, shm_shmat);
set_to_dummy_if_null(ops, sem_alloc_security);
set_to_dummy_if_null(ops, sem_free_security);
set_to_dummy_if_null(ops, sem_associate);
set_to_dummy_if_null(ops, sem_semctl);
set_to_dummy_if_null(ops, sem_semop);
set_to_dummy_if_null(ops, netlink_send);
set_to_dummy_if_null(ops, netlink_recv);
set_to_dummy_if_null(ops, register_security);
set_to_dummy_if_null(ops, unregister_security);
set_to_dummy_if_null(ops, d_instantiate);
set_to_dummy_if_null(ops, getprocattr);
set_to_dummy_if_null(ops, setprocattr);
#ifdef CONFIG_SECURITY_NETWORK
set_to_dummy_if_null(ops, unix_stream_connect);
set_to_dummy_if_null(ops, unix_may_send);
set_to_dummy_if_null(ops, socket_create);
set_to_dummy_if_null(ops, socket_post_create);
set_to_dummy_if_null(ops, socket_bind);
set_to_dummy_if_null(ops, socket_connect);
set_to_dummy_if_null(ops, socket_listen);
set_to_dummy_if_null(ops, socket_accept);
set_to_dummy_if_null(ops, socket_post_accept);
set_to_dummy_if_null(ops, socket_sendmsg);
set_to_dummy_if_null(ops, socket_recvmsg);
set_to_dummy_if_null(ops, socket_getsockname);
set_to_dummy_if_null(ops, socket_getpeername);
set_to_dummy_if_null(ops, socket_setsockopt);
set_to_dummy_if_null(ops, socket_getsockopt);
set_to_dummy_if_null(ops, socket_shutdown);
set_to_dummy_if_null(ops, socket_sock_rcv_skb);
set_to_dummy_if_null(ops, socket_getpeersec_stream);
set_to_dummy_if_null(ops, socket_getpeersec_dgram);
set_to_dummy_if_null(ops, sk_alloc_security);
set_to_dummy_if_null(ops, sk_free_security);
[LSM-IPSec]: Security association restriction. This patch series implements per packet access control via the extension of the Linux Security Modules (LSM) interface by hooks in the XFRM and pfkey subsystems that leverage IPSec security associations to label packets. Extensions to the SELinux LSM are included that leverage the patch for this purpose. This patch implements the changes necessary to the XFRM subsystem, pfkey interface, ipv4/ipv6, and xfrm_user interface to restrict a socket to use only authorized security associations (or no security association) to send/receive network packets. Patch purpose: The patch is designed to enable access control per packets based on the strongly authenticated IPSec security association. Such access controls augment the existing ones based on network interface and IP address. The former are very coarse-grained, and the latter can be spoofed. By using IPSec, the system can control access to remote hosts based on cryptographic keys generated using the IPSec mechanism. This enables access control on a per-machine basis or per-application if the remote machine is running the same mechanism and trusted to enforce the access control policy. Patch design approach: The overall approach is that policy (xfrm_policy) entries set by user-level programs (e.g., setkey for ipsec-tools) are extended with a security context that is used at policy selection time in the XFRM subsystem to restrict the sockets that can send/receive packets via security associations (xfrm_states) that are built from those policies. A presentation available at www.selinux-symposium.org/2005/presentations/session2/2-3-jaeger.pdf from the SELinux symposium describes the overall approach. Patch implementation details: On output, the policy retrieved (via xfrm_policy_lookup or xfrm_sk_policy_lookup) must be authorized for the security context of the socket and the same security context is required for resultant security association (retrieved or negotiated via racoon in ipsec-tools). This is enforced in xfrm_state_find. On input, the policy retrieved must also be authorized for the socket (at __xfrm_policy_check), and the security context of the policy must also match the security association being used. The patch has virtually no impact on packets that do not use IPSec. The existing Netfilter (outgoing) and LSM rcv_skb hooks are used as before. Also, if IPSec is used without security contexts, the impact is minimal. The LSM must allow such policies to be selected for the combination of socket and remote machine, but subsequent IPSec processing proceeds as in the original case. Testing: The pfkey interface is tested using the ipsec-tools. ipsec-tools have been modified (a separate ipsec-tools patch is available for version 0.5) that supports assignment of xfrm_policy entries and security associations with security contexts via setkey and the negotiation using the security contexts via racoon. The xfrm_user interface is tested via ad hoc programs that set security contexts. These programs are also available from me, and contain programs for setting, getting, and deleting policy for testing this interface. Testing of sa functions was done by tracing kernel behavior. Signed-off-by: Trent Jaeger <tjaeger@cse.psu.edu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-12-14 07:12:27 +00:00
set_to_dummy_if_null(ops, sk_getsid);
#endif /* CONFIG_SECURITY_NETWORK */
#ifdef CONFIG_SECURITY_NETWORK_XFRM
set_to_dummy_if_null(ops, xfrm_policy_alloc_security);
set_to_dummy_if_null(ops, xfrm_policy_clone_security);
set_to_dummy_if_null(ops, xfrm_policy_free_security);
set_to_dummy_if_null(ops, xfrm_state_alloc_security);
set_to_dummy_if_null(ops, xfrm_state_free_security);
set_to_dummy_if_null(ops, xfrm_policy_lookup);
#endif /* CONFIG_SECURITY_NETWORK_XFRM */
#ifdef CONFIG_KEYS
set_to_dummy_if_null(ops, key_alloc);
set_to_dummy_if_null(ops, key_free);
set_to_dummy_if_null(ops, key_permission);
#endif /* CONFIG_KEYS */
}