linux/security/apparmor/lsm.c
John Johansen 25e75dff51 AppArmor: Fix masking of capabilities in complain mode
AppArmor is masking the capabilities returned by capget against the
capabilities mask in the profile.  This is wrong, in complain mode the
profile has effectively all capabilities, as the profile restrictions are
not being enforced, merely tested against to determine if an access is
known by the profile.

This can result in the wrong behavior of security conscience applications
like sshd which examine their capability set, and change their behavior
accordingly.  In this case because of the masked capability set being
returned sshd fails due to DAC checks, even when the profile is in complain
mode.

Kernels affected: 2.6.36 - 3.0.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2011-06-29 02:04:44 +01:00

952 lines
25 KiB
C

/*
* AppArmor security module
*
* This file contains AppArmor LSM hooks.
*
* Copyright (C) 1998-2008 Novell/SUSE
* Copyright 2009-2010 Canonical Ltd.
*
* 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 of the
* License.
*/
#include <linux/security.h>
#include <linux/moduleparam.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/ptrace.h>
#include <linux/ctype.h>
#include <linux/sysctl.h>
#include <linux/audit.h>
#include <linux/user_namespace.h>
#include <net/sock.h>
#include "include/apparmor.h"
#include "include/apparmorfs.h"
#include "include/audit.h"
#include "include/capability.h"
#include "include/context.h"
#include "include/file.h"
#include "include/ipc.h"
#include "include/path.h"
#include "include/policy.h"
#include "include/procattr.h"
/* Flag indicating whether initialization completed */
int apparmor_initialized __initdata;
/*
* LSM hook functions
*/
/*
* free the associated aa_task_cxt and put its profiles
*/
static void apparmor_cred_free(struct cred *cred)
{
aa_free_task_context(cred->security);
cred->security = NULL;
}
/*
* allocate the apparmor part of blank credentials
*/
static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
{
/* freed by apparmor_cred_free */
struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
if (!cxt)
return -ENOMEM;
cred->security = cxt;
return 0;
}
/*
* prepare new aa_task_cxt for modification by prepare_cred block
*/
static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
gfp_t gfp)
{
/* freed by apparmor_cred_free */
struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
if (!cxt)
return -ENOMEM;
aa_dup_task_context(cxt, old->security);
new->security = cxt;
return 0;
}
/*
* transfer the apparmor data to a blank set of creds
*/
static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
{
const struct aa_task_cxt *old_cxt = old->security;
struct aa_task_cxt *new_cxt = new->security;
aa_dup_task_context(new_cxt, old_cxt);
}
static int apparmor_ptrace_access_check(struct task_struct *child,
unsigned int mode)
{
int error = cap_ptrace_access_check(child, mode);
if (error)
return error;
return aa_ptrace(current, child, mode);
}
static int apparmor_ptrace_traceme(struct task_struct *parent)
{
int error = cap_ptrace_traceme(parent);
if (error)
return error;
return aa_ptrace(parent, current, PTRACE_MODE_ATTACH);
}
/* Derived from security/commoncap.c:cap_capget */
static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
kernel_cap_t *inheritable, kernel_cap_t *permitted)
{
struct aa_profile *profile;
const struct cred *cred;
rcu_read_lock();
cred = __task_cred(target);
profile = aa_cred_profile(cred);
*effective = cred->cap_effective;
*inheritable = cred->cap_inheritable;
*permitted = cred->cap_permitted;
if (!unconfined(profile) && !COMPLAIN_MODE(profile)) {
*effective = cap_intersect(*effective, profile->caps.allow);
*permitted = cap_intersect(*permitted, profile->caps.allow);
}
rcu_read_unlock();
return 0;
}
static int apparmor_capable(struct task_struct *task, const struct cred *cred,
struct user_namespace *ns, int cap, int audit)
{
struct aa_profile *profile;
/* cap_capable returns 0 on success, else -EPERM */
int error = cap_capable(task, cred, ns, cap, audit);
if (!error) {
profile = aa_cred_profile(cred);
if (!unconfined(profile))
error = aa_capable(task, profile, cap, audit);
}
return error;
}
/**
* common_perm - basic common permission check wrapper fn for paths
* @op: operation being checked
* @path: path to check permission of (NOT NULL)
* @mask: requested permissions mask
* @cond: conditional info for the permission request (NOT NULL)
*
* Returns: %0 else error code if error or permission denied
*/
static int common_perm(int op, struct path *path, u32 mask,
struct path_cond *cond)
{
struct aa_profile *profile;
int error = 0;
profile = __aa_current_profile();
if (!unconfined(profile))
error = aa_path_perm(op, profile, path, 0, mask, cond);
return error;
}
/**
* common_perm_dir_dentry - common permission wrapper when path is dir, dentry
* @op: operation being checked
* @dir: directory of the dentry (NOT NULL)
* @dentry: dentry to check (NOT NULL)
* @mask: requested permissions mask
* @cond: conditional info for the permission request (NOT NULL)
*
* Returns: %0 else error code if error or permission denied
*/
static int common_perm_dir_dentry(int op, struct path *dir,
struct dentry *dentry, u32 mask,
struct path_cond *cond)
{
struct path path = { dir->mnt, dentry };
return common_perm(op, &path, mask, cond);
}
/**
* common_perm_mnt_dentry - common permission wrapper when mnt, dentry
* @op: operation being checked
* @mnt: mount point of dentry (NOT NULL)
* @dentry: dentry to check (NOT NULL)
* @mask: requested permissions mask
*
* Returns: %0 else error code if error or permission denied
*/
static int common_perm_mnt_dentry(int op, struct vfsmount *mnt,
struct dentry *dentry, u32 mask)
{
struct path path = { mnt, dentry };
struct path_cond cond = { dentry->d_inode->i_uid,
dentry->d_inode->i_mode
};
return common_perm(op, &path, mask, &cond);
}
/**
* common_perm_rm - common permission wrapper for operations doing rm
* @op: operation being checked
* @dir: directory that the dentry is in (NOT NULL)
* @dentry: dentry being rm'd (NOT NULL)
* @mask: requested permission mask
*
* Returns: %0 else error code if error or permission denied
*/
static int common_perm_rm(int op, struct path *dir,
struct dentry *dentry, u32 mask)
{
struct inode *inode = dentry->d_inode;
struct path_cond cond = { };
if (!inode || !dir->mnt || !mediated_filesystem(inode))
return 0;
cond.uid = inode->i_uid;
cond.mode = inode->i_mode;
return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
}
/**
* common_perm_create - common permission wrapper for operations doing create
* @op: operation being checked
* @dir: directory that dentry will be created in (NOT NULL)
* @dentry: dentry to create (NOT NULL)
* @mask: request permission mask
* @mode: created file mode
*
* Returns: %0 else error code if error or permission denied
*/
static int common_perm_create(int op, struct path *dir, struct dentry *dentry,
u32 mask, umode_t mode)
{
struct path_cond cond = { current_fsuid(), mode };
if (!dir->mnt || !mediated_filesystem(dir->dentry->d_inode))
return 0;
return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
}
static int apparmor_path_unlink(struct path *dir, struct dentry *dentry)
{
return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
}
static int apparmor_path_mkdir(struct path *dir, struct dentry *dentry,
int mode)
{
return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
S_IFDIR);
}
static int apparmor_path_rmdir(struct path *dir, struct dentry *dentry)
{
return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
}
static int apparmor_path_mknod(struct path *dir, struct dentry *dentry,
int mode, unsigned int dev)
{
return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
}
static int apparmor_path_truncate(struct path *path)
{
struct path_cond cond = { path->dentry->d_inode->i_uid,
path->dentry->d_inode->i_mode
};
if (!path->mnt || !mediated_filesystem(path->dentry->d_inode))
return 0;
return common_perm(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE,
&cond);
}
static int apparmor_path_symlink(struct path *dir, struct dentry *dentry,
const char *old_name)
{
return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
S_IFLNK);
}
static int apparmor_path_link(struct dentry *old_dentry, struct path *new_dir,
struct dentry *new_dentry)
{
struct aa_profile *profile;
int error = 0;
if (!mediated_filesystem(old_dentry->d_inode))
return 0;
profile = aa_current_profile();
if (!unconfined(profile))
error = aa_path_link(profile, old_dentry, new_dir, new_dentry);
return error;
}
static int apparmor_path_rename(struct path *old_dir, struct dentry *old_dentry,
struct path *new_dir, struct dentry *new_dentry)
{
struct aa_profile *profile;
int error = 0;
if (!mediated_filesystem(old_dentry->d_inode))
return 0;
profile = aa_current_profile();
if (!unconfined(profile)) {
struct path old_path = { old_dir->mnt, old_dentry };
struct path new_path = { new_dir->mnt, new_dentry };
struct path_cond cond = { old_dentry->d_inode->i_uid,
old_dentry->d_inode->i_mode
};
error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0,
MAY_READ | AA_MAY_META_READ | MAY_WRITE |
AA_MAY_META_WRITE | AA_MAY_DELETE,
&cond);
if (!error)
error = aa_path_perm(OP_RENAME_DEST, profile, &new_path,
0, MAY_WRITE | AA_MAY_META_WRITE |
AA_MAY_CREATE, &cond);
}
return error;
}
static int apparmor_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
mode_t mode)
{
if (!mediated_filesystem(dentry->d_inode))
return 0;
return common_perm_mnt_dentry(OP_CHMOD, mnt, dentry, AA_MAY_CHMOD);
}
static int apparmor_path_chown(struct path *path, uid_t uid, gid_t gid)
{
struct path_cond cond = { path->dentry->d_inode->i_uid,
path->dentry->d_inode->i_mode
};
if (!mediated_filesystem(path->dentry->d_inode))
return 0;
return common_perm(OP_CHOWN, path, AA_MAY_CHOWN, &cond);
}
static int apparmor_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
{
if (!mediated_filesystem(dentry->d_inode))
return 0;
return common_perm_mnt_dentry(OP_GETATTR, mnt, dentry,
AA_MAY_META_READ);
}
static int apparmor_dentry_open(struct file *file, const struct cred *cred)
{
struct aa_file_cxt *fcxt = file->f_security;
struct aa_profile *profile;
int error = 0;
if (!mediated_filesystem(file->f_path.dentry->d_inode))
return 0;
/* If in exec, permission is handled by bprm hooks.
* Cache permissions granted by the previous exec check, with
* implicit read and executable mmap which are required to
* actually execute the image.
*/
if (current->in_execve) {
fcxt->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
return 0;
}
profile = aa_cred_profile(cred);
if (!unconfined(profile)) {
struct inode *inode = file->f_path.dentry->d_inode;
struct path_cond cond = { inode->i_uid, inode->i_mode };
error = aa_path_perm(OP_OPEN, profile, &file->f_path, 0,
aa_map_file_to_perms(file), &cond);
/* todo cache full allowed permissions set and state */
fcxt->allow = aa_map_file_to_perms(file);
}
return error;
}
static int apparmor_file_alloc_security(struct file *file)
{
/* freed by apparmor_file_free_security */
file->f_security = aa_alloc_file_context(GFP_KERNEL);
if (!file->f_security)
return -ENOMEM;
return 0;
}
static void apparmor_file_free_security(struct file *file)
{
struct aa_file_cxt *cxt = file->f_security;
aa_free_file_context(cxt);
}
static int common_file_perm(int op, struct file *file, u32 mask)
{
struct aa_file_cxt *fcxt = file->f_security;
struct aa_profile *profile, *fprofile = aa_cred_profile(file->f_cred);
int error = 0;
BUG_ON(!fprofile);
if (!file->f_path.mnt ||
!mediated_filesystem(file->f_path.dentry->d_inode))
return 0;
profile = __aa_current_profile();
/* revalidate access, if task is unconfined, or the cached cred
* doesn't match or if the request is for more permissions than
* was granted.
*
* Note: the test for !unconfined(fprofile) is to handle file
* delegation from unconfined tasks
*/
if (!unconfined(profile) && !unconfined(fprofile) &&
((fprofile != profile) || (mask & ~fcxt->allow)))
error = aa_file_perm(op, profile, file, mask);
return error;
}
static int apparmor_file_permission(struct file *file, int mask)
{
return common_file_perm(OP_FPERM, file, mask);
}
static int apparmor_file_lock(struct file *file, unsigned int cmd)
{
u32 mask = AA_MAY_LOCK;
if (cmd == F_WRLCK)
mask |= MAY_WRITE;
return common_file_perm(OP_FLOCK, file, mask);
}
static int common_mmap(int op, struct file *file, unsigned long prot,
unsigned long flags)
{
struct dentry *dentry;
int mask = 0;
if (!file || !file->f_security)
return 0;
if (prot & PROT_READ)
mask |= MAY_READ;
/*
* Private mappings don't require write perms since they don't
* write back to the files
*/
if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
mask |= MAY_WRITE;
if (prot & PROT_EXEC)
mask |= AA_EXEC_MMAP;
dentry = file->f_path.dentry;
return common_file_perm(op, file, mask);
}
static int apparmor_file_mmap(struct file *file, unsigned long reqprot,
unsigned long prot, unsigned long flags,
unsigned long addr, unsigned long addr_only)
{
int rc = 0;
/* do DAC check */
rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
if (rc || addr_only)
return rc;
return common_mmap(OP_FMMAP, file, prot, flags);
}
static int apparmor_file_mprotect(struct vm_area_struct *vma,
unsigned long reqprot, unsigned long prot)
{
return common_mmap(OP_FMPROT, vma->vm_file, prot,
!(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0);
}
static int apparmor_getprocattr(struct task_struct *task, char *name,
char **value)
{
int error = -ENOENT;
struct aa_profile *profile;
/* released below */
const struct cred *cred = get_task_cred(task);
struct aa_task_cxt *cxt = cred->security;
profile = aa_cred_profile(cred);
if (strcmp(name, "current") == 0)
error = aa_getprocattr(aa_newest_version(cxt->profile),
value);
else if (strcmp(name, "prev") == 0 && cxt->previous)
error = aa_getprocattr(aa_newest_version(cxt->previous),
value);
else if (strcmp(name, "exec") == 0 && cxt->onexec)
error = aa_getprocattr(aa_newest_version(cxt->onexec),
value);
else
error = -EINVAL;
put_cred(cred);
return error;
}
static int apparmor_setprocattr(struct task_struct *task, char *name,
void *value, size_t size)
{
char *command, *args = value;
size_t arg_size;
int error;
if (size == 0)
return -EINVAL;
/* args points to a PAGE_SIZE buffer, AppArmor requires that
* the buffer must be null terminated or have size <= PAGE_SIZE -1
* so that AppArmor can null terminate them
*/
if (args[size - 1] != '\0') {
if (size == PAGE_SIZE)
return -EINVAL;
args[size] = '\0';
}
/* task can only write its own attributes */
if (current != task)
return -EACCES;
args = value;
args = strim(args);
command = strsep(&args, " ");
if (!args)
return -EINVAL;
args = skip_spaces(args);
if (!*args)
return -EINVAL;
arg_size = size - (args - (char *) value);
if (strcmp(name, "current") == 0) {
if (strcmp(command, "changehat") == 0) {
error = aa_setprocattr_changehat(args, arg_size,
!AA_DO_TEST);
} else if (strcmp(command, "permhat") == 0) {
error = aa_setprocattr_changehat(args, arg_size,
AA_DO_TEST);
} else if (strcmp(command, "changeprofile") == 0) {
error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
!AA_DO_TEST);
} else if (strcmp(command, "permprofile") == 0) {
error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
AA_DO_TEST);
} else if (strcmp(command, "permipc") == 0) {
error = aa_setprocattr_permipc(args);
} else {
struct common_audit_data sa;
COMMON_AUDIT_DATA_INIT(&sa, NONE);
sa.aad.op = OP_SETPROCATTR;
sa.aad.info = name;
sa.aad.error = -EINVAL;
return aa_audit(AUDIT_APPARMOR_DENIED,
__aa_current_profile(), GFP_KERNEL,
&sa, NULL);
}
} else if (strcmp(name, "exec") == 0) {
error = aa_setprocattr_changeprofile(args, AA_ONEXEC,
!AA_DO_TEST);
} else {
/* only support the "current" and "exec" process attributes */
return -EINVAL;
}
if (!error)
error = size;
return error;
}
static int apparmor_task_setrlimit(struct task_struct *task,
unsigned int resource, struct rlimit *new_rlim)
{
struct aa_profile *profile = __aa_current_profile();
int error = 0;
if (!unconfined(profile))
error = aa_task_setrlimit(profile, task, resource, new_rlim);
return error;
}
static struct security_operations apparmor_ops = {
.name = "apparmor",
.ptrace_access_check = apparmor_ptrace_access_check,
.ptrace_traceme = apparmor_ptrace_traceme,
.capget = apparmor_capget,
.capable = apparmor_capable,
.path_link = apparmor_path_link,
.path_unlink = apparmor_path_unlink,
.path_symlink = apparmor_path_symlink,
.path_mkdir = apparmor_path_mkdir,
.path_rmdir = apparmor_path_rmdir,
.path_mknod = apparmor_path_mknod,
.path_rename = apparmor_path_rename,
.path_chmod = apparmor_path_chmod,
.path_chown = apparmor_path_chown,
.path_truncate = apparmor_path_truncate,
.dentry_open = apparmor_dentry_open,
.inode_getattr = apparmor_inode_getattr,
.file_permission = apparmor_file_permission,
.file_alloc_security = apparmor_file_alloc_security,
.file_free_security = apparmor_file_free_security,
.file_mmap = apparmor_file_mmap,
.file_mprotect = apparmor_file_mprotect,
.file_lock = apparmor_file_lock,
.getprocattr = apparmor_getprocattr,
.setprocattr = apparmor_setprocattr,
.cred_alloc_blank = apparmor_cred_alloc_blank,
.cred_free = apparmor_cred_free,
.cred_prepare = apparmor_cred_prepare,
.cred_transfer = apparmor_cred_transfer,
.bprm_set_creds = apparmor_bprm_set_creds,
.bprm_committing_creds = apparmor_bprm_committing_creds,
.bprm_committed_creds = apparmor_bprm_committed_creds,
.bprm_secureexec = apparmor_bprm_secureexec,
.task_setrlimit = apparmor_task_setrlimit,
};
/*
* AppArmor sysfs module parameters
*/
static int param_set_aabool(const char *val, const struct kernel_param *kp);
static int param_get_aabool(char *buffer, const struct kernel_param *kp);
#define param_check_aabool(name, p) __param_check(name, p, int)
static struct kernel_param_ops param_ops_aabool = {
.set = param_set_aabool,
.get = param_get_aabool
};
static int param_set_aauint(const char *val, const struct kernel_param *kp);
static int param_get_aauint(char *buffer, const struct kernel_param *kp);
#define param_check_aauint(name, p) __param_check(name, p, int)
static struct kernel_param_ops param_ops_aauint = {
.set = param_set_aauint,
.get = param_get_aauint
};
static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
#define param_check_aalockpolicy(name, p) __param_check(name, p, int)
static struct kernel_param_ops param_ops_aalockpolicy = {
.set = param_set_aalockpolicy,
.get = param_get_aalockpolicy
};
static int param_set_audit(const char *val, struct kernel_param *kp);
static int param_get_audit(char *buffer, struct kernel_param *kp);
static int param_set_mode(const char *val, struct kernel_param *kp);
static int param_get_mode(char *buffer, struct kernel_param *kp);
/* Flag values, also controllable via /sys/module/apparmor/parameters
* We define special types as we want to do additional mediation.
*/
/* AppArmor global enforcement switch - complain, enforce, kill */
enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
module_param_call(mode, param_set_mode, param_get_mode,
&aa_g_profile_mode, S_IRUSR | S_IWUSR);
/* Debug mode */
int aa_g_debug;
module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
/* Audit mode */
enum audit_mode aa_g_audit;
module_param_call(audit, param_set_audit, param_get_audit,
&aa_g_audit, S_IRUSR | S_IWUSR);
/* Determines if audit header is included in audited messages. This
* provides more context if the audit daemon is not running
*/
int aa_g_audit_header = 1;
module_param_named(audit_header, aa_g_audit_header, aabool,
S_IRUSR | S_IWUSR);
/* lock out loading/removal of policy
* TODO: add in at boot loading of policy, which is the only way to
* load policy, if lock_policy is set
*/
int aa_g_lock_policy;
module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
S_IRUSR | S_IWUSR);
/* Syscall logging mode */
int aa_g_logsyscall;
module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
/* Maximum pathname length before accesses will start getting rejected */
unsigned int aa_g_path_max = 2 * PATH_MAX;
module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR);
/* Determines how paranoid loading of policy is and how much verification
* on the loaded policy is done.
*/
int aa_g_paranoid_load = 1;
module_param_named(paranoid_load, aa_g_paranoid_load, aabool,
S_IRUSR | S_IWUSR);
/* Boot time disable flag */
static unsigned int apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
module_param_named(enabled, apparmor_enabled, aabool, S_IRUSR);
static int __init apparmor_enabled_setup(char *str)
{
unsigned long enabled;
int error = strict_strtoul(str, 0, &enabled);
if (!error)
apparmor_enabled = enabled ? 1 : 0;
return 1;
}
__setup("apparmor=", apparmor_enabled_setup);
/* set global flag turning off the ability to load policy */
static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
if (aa_g_lock_policy)
return -EACCES;
return param_set_bool(val, kp);
}
static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
return param_get_bool(buffer, kp);
}
static int param_set_aabool(const char *val, const struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
return param_set_bool(val, kp);
}
static int param_get_aabool(char *buffer, const struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
return param_get_bool(buffer, kp);
}
static int param_set_aauint(const char *val, const struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
return param_set_uint(val, kp);
}
static int param_get_aauint(char *buffer, const struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
return param_get_uint(buffer, kp);
}
static int param_get_audit(char *buffer, struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
if (!apparmor_enabled)
return -EINVAL;
return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
}
static int param_set_audit(const char *val, struct kernel_param *kp)
{
int i;
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
if (!apparmor_enabled)
return -EINVAL;
if (!val)
return -EINVAL;
for (i = 0; i < AUDIT_MAX_INDEX; i++) {
if (strcmp(val, audit_mode_names[i]) == 0) {
aa_g_audit = i;
return 0;
}
}
return -EINVAL;
}
static int param_get_mode(char *buffer, struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
if (!apparmor_enabled)
return -EINVAL;
return sprintf(buffer, "%s", profile_mode_names[aa_g_profile_mode]);
}
static int param_set_mode(const char *val, struct kernel_param *kp)
{
int i;
if (!capable(CAP_MAC_ADMIN))
return -EPERM;
if (!apparmor_enabled)
return -EINVAL;
if (!val)
return -EINVAL;
for (i = 0; i < APPARMOR_NAMES_MAX_INDEX; i++) {
if (strcmp(val, profile_mode_names[i]) == 0) {
aa_g_profile_mode = i;
return 0;
}
}
return -EINVAL;
}
/*
* AppArmor init functions
*/
/**
* set_init_cxt - set a task context and profile on the first task.
*
* TODO: allow setting an alternate profile than unconfined
*/
static int __init set_init_cxt(void)
{
struct cred *cred = (struct cred *)current->real_cred;
struct aa_task_cxt *cxt;
cxt = aa_alloc_task_context(GFP_KERNEL);
if (!cxt)
return -ENOMEM;
cxt->profile = aa_get_profile(root_ns->unconfined);
cred->security = cxt;
return 0;
}
static int __init apparmor_init(void)
{
int error;
if (!apparmor_enabled || !security_module_enable(&apparmor_ops)) {
aa_info_message("AppArmor disabled by boot time parameter");
apparmor_enabled = 0;
return 0;
}
error = aa_alloc_root_ns();
if (error) {
AA_ERROR("Unable to allocate default profile namespace\n");
goto alloc_out;
}
error = set_init_cxt();
if (error) {
AA_ERROR("Failed to set context on init task\n");
goto register_security_out;
}
error = register_security(&apparmor_ops);
if (error) {
AA_ERROR("Unable to register AppArmor\n");
goto set_init_cxt_out;
}
/* Report that AppArmor successfully initialized */
apparmor_initialized = 1;
if (aa_g_profile_mode == APPARMOR_COMPLAIN)
aa_info_message("AppArmor initialized: complain mode enabled");
else if (aa_g_profile_mode == APPARMOR_KILL)
aa_info_message("AppArmor initialized: kill mode enabled");
else
aa_info_message("AppArmor initialized");
return error;
set_init_cxt_out:
aa_free_task_context(current->real_cred->security);
register_security_out:
aa_free_root_ns();
alloc_out:
aa_destroy_aafs();
apparmor_enabled = 0;
return error;
}
security_initcall(apparmor_init);