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OpenCloudOS-Kernel/security/apparmor/lsm.c

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/*
* 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/lsm_hooks.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/cred.h"
#include "include/file.h"
#include "include/ipc.h"
#include "include/net.h"
#include "include/path.h"
#include "include/label.h"
#include "include/policy.h"
#include "include/policy_ns.h"
#include "include/procattr.h"
#include "include/mount.h"
#include "include/secid.h"
/* Flag indicating whether initialization completed */
int apparmor_initialized;
DEFINE_PER_CPU(struct aa_buffers, aa_buffers);
/*
* LSM hook functions
*/
/*
* put the associated labels
*/
static void apparmor_cred_free(struct cred *cred)
{
aa_put_label(cred_label(cred));
cred_label(cred) = NULL;
}
/*
* allocate the apparmor part of blank credentials
*/
static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
{
cred_label(cred) = NULL;
return 0;
}
/*
* prepare new cred label for modification by prepare_cred block
*/
static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
gfp_t gfp)
{
cred_label(new) = aa_get_newest_label(cred_label(old));
return 0;
}
/*
* transfer the apparmor data to a blank set of creds
*/
static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
{
cred_label(new) = aa_get_newest_label(cred_label(old));
}
static void apparmor_task_free(struct task_struct *task)
{
aa_free_task_ctx(task_ctx(task));
task_ctx(task) = NULL;
}
static int apparmor_task_alloc(struct task_struct *task,
unsigned long clone_flags)
{
struct aa_task_ctx *new = aa_alloc_task_ctx(GFP_KERNEL);
if (!new)
return -ENOMEM;
aa_dup_task_ctx(new, task_ctx(current));
task_ctx(task) = new;
return 0;
}
static int apparmor_ptrace_access_check(struct task_struct *child,
unsigned int mode)
{
struct aa_label *tracer, *tracee;
int error;
tracer = begin_current_label_crit_section();
tracee = aa_get_task_label(child);
error = aa_may_ptrace(tracer, tracee,
(mode & PTRACE_MODE_READ) ? AA_PTRACE_READ
: AA_PTRACE_TRACE);
aa_put_label(tracee);
end_current_label_crit_section(tracer);
return error;
}
static int apparmor_ptrace_traceme(struct task_struct *parent)
{
struct aa_label *tracer, *tracee;
int error;
tracee = begin_current_label_crit_section();
tracer = aa_get_task_label(parent);
error = aa_may_ptrace(tracer, tracee, AA_PTRACE_TRACE);
aa_put_label(tracer);
end_current_label_crit_section(tracee);
return error;
}
/* 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_label *label;
const struct cred *cred;
rcu_read_lock();
cred = __task_cred(target);
label = aa_get_newest_cred_label(cred);
/*
* cap_capget is stacked ahead of this and will
* initialize effective and permitted.
*/
if (!unconfined(label)) {
struct aa_profile *profile;
struct label_it i;
label_for_each_confined(i, label, profile) {
if (COMPLAIN_MODE(profile))
continue;
*effective = cap_intersect(*effective,
profile->caps.allow);
*permitted = cap_intersect(*permitted,
profile->caps.allow);
}
}
rcu_read_unlock();
aa_put_label(label);
return 0;
}
static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
int cap, int audit)
{
struct aa_label *label;
int error = 0;
label = aa_get_newest_cred_label(cred);
if (!unconfined(label))
error = aa_capable(label, cap, audit);
aa_put_label(label);
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(const char *op, const struct path *path, u32 mask,
struct path_cond *cond)
{
struct aa_label *label;
int error = 0;
label = __begin_current_label_crit_section();
if (!unconfined(label))
error = aa_path_perm(op, label, path, 0, mask, cond);
__end_current_label_crit_section(label);
return error;
}
/**
* common_perm_cond - common permission wrapper around inode cond
* @op: operation being checked
* @path: location to check (NOT NULL)
* @mask: requested permissions mask
*
* Returns: %0 else error code if error or permission denied
*/
static int common_perm_cond(const char *op, const struct path *path, u32 mask)
{
struct path_cond cond = { d_backing_inode(path->dentry)->i_uid,
d_backing_inode(path->dentry)->i_mode
};
if (!path_mediated_fs(path->dentry))
return 0;
return common_perm(op, path, mask, &cond);
}
/**
* 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(const char *op, const struct path *dir,
struct dentry *dentry, u32 mask,
struct path_cond *cond)
{
struct path path = { .mnt = dir->mnt, .dentry = dentry };
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(const char *op, const struct path *dir,
struct dentry *dentry, u32 mask)
{
struct inode *inode = d_backing_inode(dentry);
struct path_cond cond = { };
if (!inode || !path_mediated_fs(dentry))
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(const char *op, const struct path *dir,
struct dentry *dentry, u32 mask, umode_t mode)
{
struct path_cond cond = { current_fsuid(), mode };
if (!path_mediated_fs(dir->dentry))
return 0;
return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
}
static int apparmor_path_unlink(const struct path *dir, struct dentry *dentry)
{
return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
}
static int apparmor_path_mkdir(const struct path *dir, struct dentry *dentry,
umode_t mode)
{
return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
S_IFDIR);
}
static int apparmor_path_rmdir(const struct path *dir, struct dentry *dentry)
{
return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
}
static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry,
umode_t mode, unsigned int dev)
{
return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
}
static int apparmor_path_truncate(const struct path *path)
{
return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_SETATTR);
}
static int apparmor_path_symlink(const 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, const struct path *new_dir,
struct dentry *new_dentry)
{
struct aa_label *label;
int error = 0;
if (!path_mediated_fs(old_dentry))
return 0;
label = begin_current_label_crit_section();
if (!unconfined(label))
error = aa_path_link(label, old_dentry, new_dir, new_dentry);
end_current_label_crit_section(label);
return error;
}
static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_dentry,
const struct path *new_dir, struct dentry *new_dentry)
{
struct aa_label *label;
int error = 0;
if (!path_mediated_fs(old_dentry))
return 0;
label = begin_current_label_crit_section();
if (!unconfined(label)) {
struct path old_path = { .mnt = old_dir->mnt,
.dentry = old_dentry };
struct path new_path = { .mnt = new_dir->mnt,
.dentry = new_dentry };
struct path_cond cond = { d_backing_inode(old_dentry)->i_uid,
d_backing_inode(old_dentry)->i_mode
};
error = aa_path_perm(OP_RENAME_SRC, label, &old_path, 0,
MAY_READ | AA_MAY_GETATTR | MAY_WRITE |
AA_MAY_SETATTR | AA_MAY_DELETE,
&cond);
if (!error)
error = aa_path_perm(OP_RENAME_DEST, label, &new_path,
0, MAY_WRITE | AA_MAY_SETATTR |
AA_MAY_CREATE, &cond);
}
end_current_label_crit_section(label);
return error;
}
static int apparmor_path_chmod(const struct path *path, umode_t mode)
{
return common_perm_cond(OP_CHMOD, path, AA_MAY_CHMOD);
}
static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
{
return common_perm_cond(OP_CHOWN, path, AA_MAY_CHOWN);
}
static int apparmor_inode_getattr(const struct path *path)
{
return common_perm_cond(OP_GETATTR, path, AA_MAY_GETATTR);
}
static int apparmor_file_open(struct file *file)
{
struct aa_file_ctx *fctx = file_ctx(file);
struct aa_label *label;
int error = 0;
if (!path_mediated_fs(file->f_path.dentry))
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) {
fctx->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
return 0;
}
label = aa_get_newest_cred_label(file->f_cred);
if (!unconfined(label)) {
struct inode *inode = file_inode(file);
struct path_cond cond = { inode->i_uid, inode->i_mode };
error = aa_path_perm(OP_OPEN, label, &file->f_path, 0,
aa_map_file_to_perms(file), &cond);
/* todo cache full allowed permissions set and state */
fctx->allow = aa_map_file_to_perms(file);
}
aa_put_label(label);
return error;
}
static int apparmor_file_alloc_security(struct file *file)
{
int error = 0;
/* freed by apparmor_file_free_security */
struct aa_label *label = begin_current_label_crit_section();
file->f_security = aa_alloc_file_ctx(label, GFP_KERNEL);
if (!file_ctx(file))
error = -ENOMEM;
end_current_label_crit_section(label);
return error;
}
static void apparmor_file_free_security(struct file *file)
{
aa_free_file_ctx(file_ctx(file));
}
static int common_file_perm(const char *op, struct file *file, u32 mask)
{
struct aa_label *label;
int error = 0;
/* don't reaudit files closed during inheritance */
if (file->f_path.dentry == aa_null.dentry)
return -EACCES;
label = __begin_current_label_crit_section();
error = aa_file_perm(op, label, file, mask);
__end_current_label_crit_section(label);
return error;
}
static int apparmor_file_receive(struct file *file)
{
return common_file_perm(OP_FRECEIVE, file, aa_map_file_to_perms(file));
}
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(const char *op, struct file *file, unsigned long prot,
unsigned long flags)
{
int mask = 0;
if (!file || !file_ctx(file))
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;
return common_file_perm(op, file, mask);
}
static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
unsigned long prot, unsigned long flags)
{
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_sb_mount(const char *dev_name, const struct path *path,
const char *type, unsigned long flags, void *data)
{
struct aa_label *label;
int error = 0;
/* Discard magic */
if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
flags &= ~MS_MGC_MSK;
flags &= ~AA_MS_IGNORE_MASK;
label = __begin_current_label_crit_section();
if (!unconfined(label)) {
if (flags & MS_REMOUNT)
error = aa_remount(label, path, flags, data);
else if (flags & MS_BIND)
error = aa_bind_mount(label, path, dev_name, flags);
else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE |
MS_UNBINDABLE))
error = aa_mount_change_type(label, path, flags);
else if (flags & MS_MOVE)
error = aa_move_mount(label, path, dev_name);
else
error = aa_new_mount(label, dev_name, path, type,
flags, data);
}
__end_current_label_crit_section(label);
return error;
}
static int apparmor_sb_umount(struct vfsmount *mnt, int flags)
{
struct aa_label *label;
int error = 0;
label = __begin_current_label_crit_section();
if (!unconfined(label))
error = aa_umount(label, mnt, flags);
__end_current_label_crit_section(label);
return error;
}
static int apparmor_sb_pivotroot(const struct path *old_path,
const struct path *new_path)
{
struct aa_label *label;
int error = 0;
label = aa_get_current_label();
if (!unconfined(label))
error = aa_pivotroot(label, old_path, new_path);
aa_put_label(label);
return error;
}
static int apparmor_getprocattr(struct task_struct *task, char *name,
char **value)
{
int error = -ENOENT;
/* released below */
const struct cred *cred = get_task_cred(task);
struct aa_task_ctx *ctx = task_ctx(current);
struct aa_label *label = NULL;
if (strcmp(name, "current") == 0)
label = aa_get_newest_label(cred_label(cred));
else if (strcmp(name, "prev") == 0 && ctx->previous)
label = aa_get_newest_label(ctx->previous);
else if (strcmp(name, "exec") == 0 && ctx->onexec)
label = aa_get_newest_label(ctx->onexec);
else
error = -EINVAL;
if (label)
error = aa_getprocattr(label, value);
aa_put_label(label);
put_cred(cred);
return error;
}
static int apparmor_setprocattr(const char *name, void *value,
size_t size)
{
char *command, *largs = NULL, *args = value;
size_t arg_size;
int error;
DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SETPROCATTR);
if (size == 0)
return -EINVAL;
/* AppArmor requires that the buffer must be null terminated atm */
if (args[size - 1] != '\0') {
/* null terminate */
largs = args = kmalloc(size + 1, GFP_KERNEL);
if (!args)
return -ENOMEM;
memcpy(args, value, size);
args[size] = '\0';
}
error = -EINVAL;
args = strim(args);
command = strsep(&args, " ");
if (!args)
goto out;
args = skip_spaces(args);
if (!*args)
goto out;
arg_size = size - (args - (largs ? largs : (char *) value));
if (strcmp(name, "current") == 0) {
if (strcmp(command, "changehat") == 0) {
error = aa_setprocattr_changehat(args, arg_size,
AA_CHANGE_NOFLAGS);
} else if (strcmp(command, "permhat") == 0) {
error = aa_setprocattr_changehat(args, arg_size,
AA_CHANGE_TEST);
} else if (strcmp(command, "changeprofile") == 0) {
error = aa_change_profile(args, AA_CHANGE_NOFLAGS);
} else if (strcmp(command, "permprofile") == 0) {
error = aa_change_profile(args, AA_CHANGE_TEST);
} else if (strcmp(command, "stack") == 0) {
error = aa_change_profile(args, AA_CHANGE_STACK);
} else
goto fail;
} else if (strcmp(name, "exec") == 0) {
if (strcmp(command, "exec") == 0)
error = aa_change_profile(args, AA_CHANGE_ONEXEC);
else if (strcmp(command, "stack") == 0)
error = aa_change_profile(args, (AA_CHANGE_ONEXEC |
AA_CHANGE_STACK));
else
goto fail;
} else
/* only support the "current" and "exec" process attributes */
goto fail;
if (!error)
error = size;
out:
kfree(largs);
return error;
fail:
aad(&sa)->label = begin_current_label_crit_section();
aad(&sa)->info = name;
aad(&sa)->error = error = -EINVAL;
aa_audit_msg(AUDIT_APPARMOR_DENIED, &sa, NULL);
end_current_label_crit_section(aad(&sa)->label);
goto out;
}
/**
* apparmor_bprm_committing_creds - do task cleanup on committing new creds
* @bprm: binprm for the exec (NOT NULL)
*/
static void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
{
struct aa_label *label = aa_current_raw_label();
struct aa_label *new_label = cred_label(bprm->cred);
/* bail out if unconfined or not changing profile */
if ((new_label->proxy == label->proxy) ||
(unconfined(new_label)))
return;
aa_inherit_files(bprm->cred, current->files);
current->pdeath_signal = 0;
/* reset soft limits and set hard limits for the new label */
__aa_transition_rlimits(label, new_label);
}
/**
* apparmor_bprm_committed_cred - do cleanup after new creds committed
* @bprm: binprm for the exec (NOT NULL)
*/
static void apparmor_bprm_committed_creds(struct linux_binprm *bprm)
{
/* clear out temporary/transitional state from the context */
aa_clear_task_ctx_trans(task_ctx(current));
return;
}
static void apparmor_task_getsecid(struct task_struct *p, u32 *secid)
{
struct aa_label *label = aa_get_task_label(p);
*secid = label->secid;
aa_put_label(label);
}
static int apparmor_task_setrlimit(struct task_struct *task,
unsigned int resource, struct rlimit *new_rlim)
{
struct aa_label *label = __begin_current_label_crit_section();
int error = 0;
if (!unconfined(label))
error = aa_task_setrlimit(label, task, resource, new_rlim);
__end_current_label_crit_section(label);
return error;
}
static int apparmor_task_kill(struct task_struct *target, struct siginfo *info,
int sig, const struct cred *cred)
{
struct aa_label *cl, *tl;
int error;
if (cred) {
/*
* Dealing with USB IO specific behavior
*/
cl = aa_get_newest_cred_label(cred);
tl = aa_get_task_label(target);
error = aa_may_signal(cl, tl, sig);
aa_put_label(cl);
aa_put_label(tl);
return error;
}
cl = __begin_current_label_crit_section();
tl = aa_get_task_label(target);
error = aa_may_signal(cl, tl, sig);
aa_put_label(tl);
__end_current_label_crit_section(cl);
return error;
}
/**
* apparmor_sk_alloc_security - allocate and attach the sk_security field
*/
static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags)
{
struct aa_sk_ctx *ctx;
ctx = kzalloc(sizeof(*ctx), flags);
if (!ctx)
return -ENOMEM;
SK_CTX(sk) = ctx;
return 0;
}
/**
* apparmor_sk_free_security - free the sk_security field
*/
static void apparmor_sk_free_security(struct sock *sk)
{
struct aa_sk_ctx *ctx = SK_CTX(sk);
SK_CTX(sk) = NULL;
aa_put_label(ctx->label);
aa_put_label(ctx->peer);
kfree(ctx);
}
/**
* apparmor_clone_security - clone the sk_security field
*/
static void apparmor_sk_clone_security(const struct sock *sk,
struct sock *newsk)
{
struct aa_sk_ctx *ctx = SK_CTX(sk);
struct aa_sk_ctx *new = SK_CTX(newsk);
new->label = aa_get_label(ctx->label);
new->peer = aa_get_label(ctx->peer);
}
/**
* apparmor_socket_create - check perms before creating a new socket
*/
static int apparmor_socket_create(int family, int type, int protocol, int kern)
{
struct aa_label *label;
int error = 0;
AA_BUG(in_interrupt());
label = begin_current_label_crit_section();
if (!(kern || unconfined(label)))
error = af_select(family,
create_perm(label, family, type, protocol),
aa_af_perm(label, OP_CREATE, AA_MAY_CREATE,
family, type, protocol));
end_current_label_crit_section(label);
return error;
}
/**
* apparmor_socket_post_create - setup the per-socket security struct
*
* Note:
* - kernel sockets currently labeled unconfined but we may want to
* move to a special kernel label
* - socket may not have sk here if created with sock_create_lite or
* sock_alloc. These should be accept cases which will be handled in
* sock_graft.
*/
static int apparmor_socket_post_create(struct socket *sock, int family,
int type, int protocol, int kern)
{
struct aa_label *label;
if (kern) {
struct aa_ns *ns = aa_get_current_ns();
label = aa_get_label(ns_unconfined(ns));
aa_put_ns(ns);
} else
label = aa_get_current_label();
if (sock->sk) {
struct aa_sk_ctx *ctx = SK_CTX(sock->sk);
aa_put_label(ctx->label);
ctx->label = aa_get_label(label);
}
aa_put_label(label);
return 0;
}
/**
* apparmor_socket_bind - check perms before bind addr to socket
*/
static int apparmor_socket_bind(struct socket *sock,
struct sockaddr *address, int addrlen)
{
AA_BUG(!sock);
AA_BUG(!sock->sk);
AA_BUG(!address);
AA_BUG(in_interrupt());
return af_select(sock->sk->sk_family,
bind_perm(sock, address, addrlen),
aa_sk_perm(OP_BIND, AA_MAY_BIND, sock->sk));
}
/**
* apparmor_socket_connect - check perms before connecting @sock to @address
*/
static int apparmor_socket_connect(struct socket *sock,
struct sockaddr *address, int addrlen)
{
AA_BUG(!sock);
AA_BUG(!sock->sk);
AA_BUG(!address);
AA_BUG(in_interrupt());
return af_select(sock->sk->sk_family,
connect_perm(sock, address, addrlen),
aa_sk_perm(OP_CONNECT, AA_MAY_CONNECT, sock->sk));
}
/**
* apparmor_socket_list - check perms before allowing listen
*/
static int apparmor_socket_listen(struct socket *sock, int backlog)
{
AA_BUG(!sock);
AA_BUG(!sock->sk);
AA_BUG(in_interrupt());
return af_select(sock->sk->sk_family,
listen_perm(sock, backlog),
aa_sk_perm(OP_LISTEN, AA_MAY_LISTEN, sock->sk));
}
/**
* apparmor_socket_accept - check perms before accepting a new connection.
*
* Note: while @newsock is created and has some information, the accept
* has not been done.
*/
static int apparmor_socket_accept(struct socket *sock, struct socket *newsock)
{
AA_BUG(!sock);
AA_BUG(!sock->sk);
AA_BUG(!newsock);
AA_BUG(in_interrupt());
return af_select(sock->sk->sk_family,
accept_perm(sock, newsock),
aa_sk_perm(OP_ACCEPT, AA_MAY_ACCEPT, sock->sk));
}
static int aa_sock_msg_perm(const char *op, u32 request, struct socket *sock,
struct msghdr *msg, int size)
{
AA_BUG(!sock);
AA_BUG(!sock->sk);
AA_BUG(!msg);
AA_BUG(in_interrupt());
return af_select(sock->sk->sk_family,
msg_perm(op, request, sock, msg, size),
aa_sk_perm(op, request, sock->sk));
}
/**
* apparmor_socket_sendmsg - check perms before sending msg to another socket
*/
static int apparmor_socket_sendmsg(struct socket *sock,
struct msghdr *msg, int size)
{
return aa_sock_msg_perm(OP_SENDMSG, AA_MAY_SEND, sock, msg, size);
}
/**
* apparmor_socket_recvmsg - check perms before receiving a message
*/
static int apparmor_socket_recvmsg(struct socket *sock,
struct msghdr *msg, int size, int flags)
{
return aa_sock_msg_perm(OP_RECVMSG, AA_MAY_RECEIVE, sock, msg, size);
}
/* revaliation, get/set attr, shutdown */
static int aa_sock_perm(const char *op, u32 request, struct socket *sock)
{
AA_BUG(!sock);
AA_BUG(!sock->sk);
AA_BUG(in_interrupt());
return af_select(sock->sk->sk_family,
sock_perm(op, request, sock),
aa_sk_perm(op, request, sock->sk));
}
/**
* apparmor_socket_getsockname - check perms before getting the local address
*/
static int apparmor_socket_getsockname(struct socket *sock)
{
return aa_sock_perm(OP_GETSOCKNAME, AA_MAY_GETATTR, sock);
}
/**
* apparmor_socket_getpeername - check perms before getting remote address
*/
static int apparmor_socket_getpeername(struct socket *sock)
{
return aa_sock_perm(OP_GETPEERNAME, AA_MAY_GETATTR, sock);
}
/* revaliation, get/set attr, opt */
static int aa_sock_opt_perm(const char *op, u32 request, struct socket *sock,
int level, int optname)
{
AA_BUG(!sock);
AA_BUG(!sock->sk);
AA_BUG(in_interrupt());
return af_select(sock->sk->sk_family,
opt_perm(op, request, sock, level, optname),
aa_sk_perm(op, request, sock->sk));
}
/**
* apparmor_getsockopt - check perms before getting socket options
*/
static int apparmor_socket_getsockopt(struct socket *sock, int level,
int optname)
{
return aa_sock_opt_perm(OP_GETSOCKOPT, AA_MAY_GETOPT, sock,
level, optname);
}
/**
* apparmor_setsockopt - check perms before setting socket options
*/
static int apparmor_socket_setsockopt(struct socket *sock, int level,
int optname)
{
return aa_sock_opt_perm(OP_SETSOCKOPT, AA_MAY_SETOPT, sock,
level, optname);
}
/**
* apparmor_socket_shutdown - check perms before shutting down @sock conn
*/
static int apparmor_socket_shutdown(struct socket *sock, int how)
{
return aa_sock_perm(OP_SHUTDOWN, AA_MAY_SHUTDOWN, sock);
}
/**
* apparmor_socket_sock_recv_skb - check perms before associating skb to sk
*
* Note: can not sleep may be called with locks held
*
* dont want protocol specific in __skb_recv_datagram()
* to deny an incoming connection socket_sock_rcv_skb()
*/
static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
return 0;
}
static struct aa_label *sk_peer_label(struct sock *sk)
{
struct aa_sk_ctx *ctx = SK_CTX(sk);
if (ctx->peer)
return ctx->peer;
return ERR_PTR(-ENOPROTOOPT);
}
/**
* apparmor_socket_getpeersec_stream - get security context of peer
*
* Note: for tcp only valid if using ipsec or cipso on lan
*/
static int apparmor_socket_getpeersec_stream(struct socket *sock,
char __user *optval,
int __user *optlen,
unsigned int len)
{
char *name;
int slen, error = 0;
struct aa_label *label;
struct aa_label *peer;
label = begin_current_label_crit_section();
peer = sk_peer_label(sock->sk);
if (IS_ERR(peer)) {
error = PTR_ERR(peer);
goto done;
}
slen = aa_label_asxprint(&name, labels_ns(label), peer,
FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
FLAG_HIDDEN_UNCONFINED, GFP_KERNEL);
/* don't include terminating \0 in slen, it breaks some apps */
if (slen < 0) {
error = -ENOMEM;
} else {
if (slen > len) {
error = -ERANGE;
} else if (copy_to_user(optval, name, slen)) {
error = -EFAULT;
goto out;
}
if (put_user(slen, optlen))
error = -EFAULT;
out:
kfree(name);
}
done:
end_current_label_crit_section(label);
return error;
}
/**
* apparmor_socket_getpeersec_dgram - get security label of packet
* @sock: the peer socket
* @skb: packet data
* @secid: pointer to where to put the secid of the packet
*
* Sets the netlabel socket state on sk from parent
*/
static int apparmor_socket_getpeersec_dgram(struct socket *sock,
struct sk_buff *skb, u32 *secid)
{
/* TODO: requires secid support */
return -ENOPROTOOPT;
}
/**
* apparmor_sock_graft - Initialize newly created socket
* @sk: child sock
* @parent: parent socket
*
* Note: could set off of SOCK_CTX(parent) but need to track inode and we can
* just set sk security information off of current creating process label
* Labeling of sk for accept case - probably should be sock based
* instead of task, because of the case where an implicitly labeled
* socket is shared by different tasks.
*/
static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
{
struct aa_sk_ctx *ctx = SK_CTX(sk);
if (!ctx->label)
ctx->label = aa_get_current_label();
}
static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
LSM_HOOK_INIT(capget, apparmor_capget),
LSM_HOOK_INIT(capable, apparmor_capable),
LSM_HOOK_INIT(sb_mount, apparmor_sb_mount),
LSM_HOOK_INIT(sb_umount, apparmor_sb_umount),
LSM_HOOK_INIT(sb_pivotroot, apparmor_sb_pivotroot),
LSM_HOOK_INIT(path_link, apparmor_path_link),
LSM_HOOK_INIT(path_unlink, apparmor_path_unlink),
LSM_HOOK_INIT(path_symlink, apparmor_path_symlink),
LSM_HOOK_INIT(path_mkdir, apparmor_path_mkdir),
LSM_HOOK_INIT(path_rmdir, apparmor_path_rmdir),
LSM_HOOK_INIT(path_mknod, apparmor_path_mknod),
LSM_HOOK_INIT(path_rename, apparmor_path_rename),
LSM_HOOK_INIT(path_chmod, apparmor_path_chmod),
LSM_HOOK_INIT(path_chown, apparmor_path_chown),
LSM_HOOK_INIT(path_truncate, apparmor_path_truncate),
LSM_HOOK_INIT(inode_getattr, apparmor_inode_getattr),
LSM_HOOK_INIT(file_open, apparmor_file_open),
LSM_HOOK_INIT(file_receive, apparmor_file_receive),
LSM_HOOK_INIT(file_permission, apparmor_file_permission),
LSM_HOOK_INIT(file_alloc_security, apparmor_file_alloc_security),
LSM_HOOK_INIT(file_free_security, apparmor_file_free_security),
LSM_HOOK_INIT(mmap_file, apparmor_mmap_file),
LSM_HOOK_INIT(file_mprotect, apparmor_file_mprotect),
LSM_HOOK_INIT(file_lock, apparmor_file_lock),
LSM_HOOK_INIT(getprocattr, apparmor_getprocattr),
LSM_HOOK_INIT(setprocattr, apparmor_setprocattr),
LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security),
LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security),
LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security),
LSM_HOOK_INIT(socket_create, apparmor_socket_create),
LSM_HOOK_INIT(socket_post_create, apparmor_socket_post_create),
LSM_HOOK_INIT(socket_bind, apparmor_socket_bind),
LSM_HOOK_INIT(socket_connect, apparmor_socket_connect),
LSM_HOOK_INIT(socket_listen, apparmor_socket_listen),
LSM_HOOK_INIT(socket_accept, apparmor_socket_accept),
LSM_HOOK_INIT(socket_sendmsg, apparmor_socket_sendmsg),
LSM_HOOK_INIT(socket_recvmsg, apparmor_socket_recvmsg),
LSM_HOOK_INIT(socket_getsockname, apparmor_socket_getsockname),
LSM_HOOK_INIT(socket_getpeername, apparmor_socket_getpeername),
LSM_HOOK_INIT(socket_getsockopt, apparmor_socket_getsockopt),
LSM_HOOK_INIT(socket_setsockopt, apparmor_socket_setsockopt),
LSM_HOOK_INIT(socket_shutdown, apparmor_socket_shutdown),
LSM_HOOK_INIT(socket_sock_rcv_skb, apparmor_socket_sock_rcv_skb),
LSM_HOOK_INIT(socket_getpeersec_stream,
apparmor_socket_getpeersec_stream),
LSM_HOOK_INIT(socket_getpeersec_dgram,
apparmor_socket_getpeersec_dgram),
LSM_HOOK_INIT(sock_graft, apparmor_sock_graft),
LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank),
LSM_HOOK_INIT(cred_free, apparmor_cred_free),
LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare),
LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer),
LSM_HOOK_INIT(bprm_set_creds, apparmor_bprm_set_creds),
LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds),
LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds),
LSM_HOOK_INIT(task_free, apparmor_task_free),
LSM_HOOK_INIT(task_alloc, apparmor_task_alloc),
LSM_HOOK_INIT(task_getsecid, apparmor_task_getsecid),
LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit),
LSM_HOOK_INIT(task_kill, apparmor_task_kill),
#ifdef CONFIG_AUDIT
LSM_HOOK_INIT(audit_rule_init, aa_audit_rule_init),
LSM_HOOK_INIT(audit_rule_known, aa_audit_rule_known),
LSM_HOOK_INIT(audit_rule_match, aa_audit_rule_match),
LSM_HOOK_INIT(audit_rule_free, aa_audit_rule_free),
#endif
LSM_HOOK_INIT(secid_to_secctx, apparmor_secid_to_secctx),
LSM_HOOK_INIT(secctx_to_secid, apparmor_secctx_to_secid),
LSM_HOOK_INIT(release_secctx, apparmor_release_secctx),
};
/*
* 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 param_check_bool
static const struct kernel_param_ops param_ops_aabool = {
.flags = KERNEL_PARAM_OPS_FL_NOARG,
.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 param_check_uint
static const 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 param_check_bool
static const struct kernel_param_ops param_ops_aalockpolicy = {
.flags = KERNEL_PARAM_OPS_FL_NOARG,
.set = param_set_aalockpolicy,
.get = param_get_aalockpolicy
};
static int param_set_audit(const char *val, const struct kernel_param *kp);
static int param_get_audit(char *buffer, const struct kernel_param *kp);
static int param_set_mode(const char *val, const struct kernel_param *kp);
static int param_get_mode(char *buffer, const 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);
/* whether policy verification hashing is enabled */
bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT);
#ifdef CONFIG_SECURITY_APPARMOR_HASH
module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR);
#endif
/* Debug mode */
bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_APPARMOR_DEBUG_MESSAGES);
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
*/
bool aa_g_audit_header = true;
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
*/
bool aa_g_lock_policy;
module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
S_IRUSR | S_IWUSR);
/* Syscall logging mode */
bool 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);
/* Determines how paranoid loading of policy is and how much verification
* on the loaded policy is done.
* DEPRECATED: read only as strict checking of load is always done now
* that none root users (user namespaces) can load policy.
*/
bool aa_g_paranoid_load = true;
module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO);
/* Boot time disable flag */
static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
module_param_named(enabled, apparmor_enabled, bool, S_IRUGO);
static int __init apparmor_enabled_setup(char *str)
{
unsigned long enabled;
int error = kstrtoul(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 (!apparmor_enabled)
return -EINVAL;
if (apparmor_initialized && !policy_admin_capable(NULL))
return -EPERM;
return param_set_bool(val, kp);
}
static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
{
if (!apparmor_enabled)
return -EINVAL;
if (apparmor_initialized && !policy_view_capable(NULL))
return -EPERM;
return param_get_bool(buffer, kp);
}
static int param_set_aabool(const char *val, const struct kernel_param *kp)
{
if (!apparmor_enabled)
return -EINVAL;
if (apparmor_initialized && !policy_admin_capable(NULL))
return -EPERM;
return param_set_bool(val, kp);
}
static int param_get_aabool(char *buffer, const struct kernel_param *kp)
{
if (!apparmor_enabled)
return -EINVAL;
if (apparmor_initialized && !policy_view_capable(NULL))
return -EPERM;
return param_get_bool(buffer, kp);
}
static int param_set_aauint(const char *val, const struct kernel_param *kp)
{
int error;
if (!apparmor_enabled)
return -EINVAL;
/* file is ro but enforce 2nd line check */
if (apparmor_initialized)
return -EPERM;
error = param_set_uint(val, kp);
pr_info("AppArmor: buffer size set to %d bytes\n", aa_g_path_max);
return error;
}
static int param_get_aauint(char *buffer, const struct kernel_param *kp)
{
if (!apparmor_enabled)
return -EINVAL;
if (apparmor_initialized && !policy_view_capable(NULL))
return -EPERM;
return param_get_uint(buffer, kp);
}
static int param_get_audit(char *buffer, const struct kernel_param *kp)
{
if (!apparmor_enabled)
return -EINVAL;
if (apparmor_initialized && !policy_view_capable(NULL))
return -EPERM;
return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
}
static int param_set_audit(const char *val, const struct kernel_param *kp)
{
int i;
if (!apparmor_enabled)
return -EINVAL;
if (!val)
return -EINVAL;
if (apparmor_initialized && !policy_admin_capable(NULL))
return -EPERM;
i = match_string(audit_mode_names, AUDIT_MAX_INDEX, val);
if (i < 0)
return -EINVAL;
aa_g_audit = i;
return 0;
}
static int param_get_mode(char *buffer, const struct kernel_param *kp)
{
if (!apparmor_enabled)
return -EINVAL;
if (apparmor_initialized && !policy_view_capable(NULL))
return -EPERM;
return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]);
}
static int param_set_mode(const char *val, const struct kernel_param *kp)
{
int i;
if (!apparmor_enabled)
return -EINVAL;
if (!val)
return -EINVAL;
if (apparmor_initialized && !policy_admin_capable(NULL))
return -EPERM;
i = match_string(aa_profile_mode_names, APPARMOR_MODE_NAMES_MAX_INDEX,
val);
if (i < 0)
return -EINVAL;
aa_g_profile_mode = i;
return 0;
}
/*
* AppArmor init functions
*/
/**
* set_init_ctx - set a task context and profile on the first task.
*
* TODO: allow setting an alternate profile than unconfined
*/
static int __init set_init_ctx(void)
{
struct cred *cred = (struct cred *)current->real_cred;
struct aa_task_ctx *ctx;
ctx = aa_alloc_task_ctx(GFP_KERNEL);
if (!ctx)
return -ENOMEM;
cred_label(cred) = aa_get_label(ns_unconfined(root_ns));
task_ctx(current) = ctx;
return 0;
}
static void destroy_buffers(void)
{
u32 i, j;
for_each_possible_cpu(i) {
for_each_cpu_buffer(j) {
kfree(per_cpu(aa_buffers, i).buf[j]);
per_cpu(aa_buffers, i).buf[j] = NULL;
}
}
}
static int __init alloc_buffers(void)
{
u32 i, j;
for_each_possible_cpu(i) {
for_each_cpu_buffer(j) {
char *buffer;
if (cpu_to_node(i) > num_online_nodes())
/* fallback to kmalloc for offline nodes */
buffer = kmalloc(aa_g_path_max, GFP_KERNEL);
else
buffer = kmalloc_node(aa_g_path_max, GFP_KERNEL,
cpu_to_node(i));
if (!buffer) {
destroy_buffers();
return -ENOMEM;
}
per_cpu(aa_buffers, i).buf[j] = buffer;
}
}
return 0;
}
#ifdef CONFIG_SYSCTL
static int apparmor_dointvec(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
if (!policy_admin_capable(NULL))
return -EPERM;
if (!apparmor_enabled)
return -EINVAL;
return proc_dointvec(table, write, buffer, lenp, ppos);
}
static struct ctl_path apparmor_sysctl_path[] = {
{ .procname = "kernel", },
{ }
};
static struct ctl_table apparmor_sysctl_table[] = {
{
.procname = "unprivileged_userns_apparmor_policy",
.data = &unprivileged_userns_apparmor_policy,
.maxlen = sizeof(int),
.mode = 0600,
.proc_handler = apparmor_dointvec,
},
{ }
};
static int __init apparmor_init_sysctl(void)
{
return register_sysctl_paths(apparmor_sysctl_path,
apparmor_sysctl_table) ? 0 : -ENOMEM;
}
#else
static inline int apparmor_init_sysctl(void)
{
return 0;
}
#endif /* CONFIG_SYSCTL */
static int __init apparmor_init(void)
{
int error;
if (!apparmor_enabled || !security_module_enable("apparmor")) {
aa_info_message("AppArmor disabled by boot time parameter");
apparmor_enabled = false;
return 0;
}
aa_secids_init();
error = aa_setup_dfa_engine();
if (error) {
AA_ERROR("Unable to setup dfa engine\n");
goto alloc_out;
}
error = aa_alloc_root_ns();
if (error) {
AA_ERROR("Unable to allocate default profile namespace\n");
goto alloc_out;
}
error = apparmor_init_sysctl();
if (error) {
AA_ERROR("Unable to register sysctls\n");
goto alloc_out;
}
error = alloc_buffers();
if (error) {
AA_ERROR("Unable to allocate work buffers\n");
goto buffers_out;
}
error = set_init_ctx();
if (error) {
AA_ERROR("Failed to set context on init task\n");
aa_free_root_ns();
goto buffers_out;
}
security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
"apparmor");
/* 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;
buffers_out:
destroy_buffers();
alloc_out:
aa_destroy_aafs();
aa_teardown_dfa_engine();
apparmor_enabled = false;
return error;
}
security_initcall(apparmor_init);
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