linux/security/apparmor/lsm.c
Paul Moore 4ebd7651bf lsm: separate security_task_getsecid() into subjective and objective variants
Of the three LSMs that implement the security_task_getsecid() LSM
hook, all three LSMs provide the task's objective security
credentials.  This turns out to be unfortunate as most of the hook's
callers seem to expect the task's subjective credentials, although
a small handful of callers do correctly expect the objective
credentials.

This patch is the first step towards fixing the problem: it splits
the existing security_task_getsecid() hook into two variants, one
for the subjective creds, one for the objective creds.

  void security_task_getsecid_subj(struct task_struct *p,
				   u32 *secid);
  void security_task_getsecid_obj(struct task_struct *p,
				  u32 *secid);

While this patch does fix all of the callers to use the correct
variant, in order to keep this patch focused on the callers and to
ease review, the LSMs continue to use the same implementation for
both hooks.  The net effect is that this patch should not change
the behavior of the kernel in any way, it will be up to the latter
LSM specific patches in this series to change the hook
implementations and return the correct credentials.

Acked-by: Mimi Zohar <zohar@linux.ibm.com> (IMA)
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-03-22 15:23:32 -04:00

1913 lines
49 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* AppArmor security module
*
* This file contains AppArmor LSM hooks.
*
* Copyright (C) 1998-2008 Novell/SUSE
* Copyright 2009-2010 Canonical Ltd.
*/
#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 <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv6.h>
#include <linux/zlib.h>
#include <net/sock.h>
#include <uapi/linux/mount.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;
union aa_buffer {
struct list_head list;
char buffer[1];
};
#define RESERVE_COUNT 2
static int reserve_count = RESERVE_COUNT;
static int buffer_count;
static LIST_HEAD(aa_global_buffers);
static DEFINE_SPINLOCK(aa_buffers_lock);
/*
* LSM hook functions
*/
/*
* put the associated labels
*/
static void apparmor_cred_free(struct cred *cred)
{
aa_put_label(cred_label(cred));
set_cred_label(cred, NULL);
}
/*
* allocate the apparmor part of blank credentials
*/
static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
{
set_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)
{
set_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)
{
set_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));
}
static int apparmor_task_alloc(struct task_struct *task,
unsigned long clone_flags)
{
struct aa_task_ctx *new = task_ctx(task);
aa_dup_task_ctx(new, task_ctx(current));
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, unsigned int opts)
{
struct aa_label *label;
int error = 0;
label = aa_get_newest_cred_label(cred);
if (!unconfined(label))
error = aa_capable(label, cap, opts);
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 user_namespace *mnt_userns = mnt_user_ns(path->mnt);
struct path_cond cond = {
i_uid_into_mnt(mnt_userns, d_backing_inode(path->dentry)),
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 user_namespace *mnt_userns = mnt_user_ns(dir->mnt);
struct path_cond cond = { };
if (!inode || !path_mediated_fs(dentry))
return 0;
cond.uid = i_uid_into_mnt(mnt_userns, inode);
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 user_namespace *mnt_userns = mnt_user_ns(old_dir->mnt);
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 = {
i_uid_into_mnt(mnt_userns, d_backing_inode(old_dentry)),
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 user_namespace *mnt_userns = file_mnt_user_ns(file);
struct inode *inode = file_inode(file);
struct path_cond cond = {
i_uid_into_mnt(mnt_userns, inode),
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)
{
struct aa_file_ctx *ctx = file_ctx(file);
struct aa_label *label = begin_current_label_crit_section();
spin_lock_init(&ctx->lock);
rcu_assign_pointer(ctx->label, aa_get_label(label));
end_current_label_crit_section(label);
return 0;
}
static void apparmor_file_free_security(struct file *file)
{
struct aa_file_ctx *ctx = file_ctx(file);
if (ctx)
aa_put_label(rcu_access_pointer(ctx->label));
}
static int common_file_perm(const char *op, struct file *file, u32 mask,
bool in_atomic)
{
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, in_atomic);
__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),
false);
}
static int apparmor_file_permission(struct file *file, int mask)
{
return common_file_perm(OP_FPERM, file, mask, false);
}
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, false);
}
static int common_mmap(const char *op, struct file *file, unsigned long prot,
unsigned long flags, bool in_atomic)
{
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, in_atomic);
}
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, GFP_ATOMIC);
}
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,
false);
}
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 kernel_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);
if (new->label)
aa_put_label(new->label);
new->label = aa_get_label(ctx->label);
if (new->peer)
aa_put_label(new->peer);
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);
}
#ifdef CONFIG_NETWORK_SECMARK
/**
* 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)
{
struct aa_sk_ctx *ctx = SK_CTX(sk);
if (!skb->secmark)
return 0;
return apparmor_secmark_check(ctx->label, OP_RECVMSG, AA_MAY_RECEIVE,
skb->secmark, sk);
}
#endif
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();
}
#ifdef CONFIG_NETWORK_SECMARK
static int apparmor_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
struct request_sock *req)
{
struct aa_sk_ctx *ctx = SK_CTX(sk);
if (!skb->secmark)
return 0;
return apparmor_secmark_check(ctx->label, OP_CONNECT, AA_MAY_CONNECT,
skb->secmark, sk);
}
#endif
/*
* The cred blob is a pointer to, not an instance of, an aa_task_ctx.
*/
struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = {
.lbs_cred = sizeof(struct aa_task_ctx *),
.lbs_file = sizeof(struct aa_file_ctx),
.lbs_task = sizeof(struct aa_task_ctx),
};
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),
#ifdef CONFIG_NETWORK_SECMARK
LSM_HOOK_INIT(socket_sock_rcv_skb, apparmor_socket_sock_rcv_skb),
#endif
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),
#ifdef CONFIG_NETWORK_SECMARK
LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request),
#endif
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_creds_for_exec, apparmor_bprm_creds_for_exec),
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_subj, apparmor_task_getsecid),
LSM_HOOK_INIT(task_getsecid_obj, 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_aacompressionlevel(const char *val,
const struct kernel_param *kp);
static int param_get_aacompressionlevel(char *buffer,
const struct kernel_param *kp);
#define param_check_aacompressionlevel param_check_int
static const struct kernel_param_ops param_ops_aacompressionlevel = {
.set = param_set_aacompressionlevel,
.get = param_get_aacompressionlevel
};
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
/* policy loaddata compression level */
int aa_g_rawdata_compression_level = Z_DEFAULT_COMPRESSION;
module_param_named(rawdata_compression_level, aa_g_rawdata_compression_level,
aacompressionlevel, 0400);
/* 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);
static int param_get_aaintbool(char *buffer, const struct kernel_param *kp);
static int param_set_aaintbool(const char *val, const struct kernel_param *kp);
#define param_check_aaintbool param_check_int
static const struct kernel_param_ops param_ops_aaintbool = {
.set = param_set_aaintbool,
.get = param_get_aaintbool
};
/* Boot time disable flag */
static int apparmor_enabled __lsm_ro_after_init = 1;
module_param_named(enabled, apparmor_enabled, aaintbool, 0444);
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);
aa_g_path_max = max_t(uint32_t, aa_g_path_max, sizeof(union aa_buffer));
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);
}
/* Can only be set before AppArmor is initialized (i.e. on boot cmdline). */
static int param_set_aaintbool(const char *val, const struct kernel_param *kp)
{
struct kernel_param kp_local;
bool value;
int error;
if (apparmor_initialized)
return -EPERM;
/* Create local copy, with arg pointing to bool type. */
value = !!*((int *)kp->arg);
memcpy(&kp_local, kp, sizeof(kp_local));
kp_local.arg = &value;
error = param_set_bool(val, &kp_local);
if (!error)
*((int *)kp->arg) = *((bool *)kp_local.arg);
return error;
}
/*
* To avoid changing /sys/module/apparmor/parameters/enabled from Y/N to
* 1/0, this converts the "int that is actually bool" back to bool for
* display in the /sys filesystem, while keeping it "int" for the LSM
* infrastructure.
*/
static int param_get_aaintbool(char *buffer, const struct kernel_param *kp)
{
struct kernel_param kp_local;
bool value;
/* Create local copy, with arg pointing to bool type. */
value = !!*((int *)kp->arg);
memcpy(&kp_local, kp, sizeof(kp_local));
kp_local.arg = &value;
return param_get_bool(buffer, &kp_local);
}
static int param_set_aacompressionlevel(const char *val,
const struct kernel_param *kp)
{
int error;
if (!apparmor_enabled)
return -EINVAL;
if (apparmor_initialized)
return -EPERM;
error = param_set_int(val, kp);
aa_g_rawdata_compression_level = clamp(aa_g_rawdata_compression_level,
Z_NO_COMPRESSION,
Z_BEST_COMPRESSION);
pr_info("AppArmor: policy rawdata compression level set to %u\n",
aa_g_rawdata_compression_level);
return error;
}
static int param_get_aacompressionlevel(char *buffer,
const struct kernel_param *kp)
{
if (!apparmor_enabled)
return -EINVAL;
if (apparmor_initialized && !policy_view_capable(NULL))
return -EPERM;
return param_get_int(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;
}
char *aa_get_buffer(bool in_atomic)
{
union aa_buffer *aa_buf;
bool try_again = true;
gfp_t flags = (GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
retry:
spin_lock(&aa_buffers_lock);
if (buffer_count > reserve_count ||
(in_atomic && !list_empty(&aa_global_buffers))) {
aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer,
list);
list_del(&aa_buf->list);
buffer_count--;
spin_unlock(&aa_buffers_lock);
return &aa_buf->buffer[0];
}
if (in_atomic) {
/*
* out of reserve buffers and in atomic context so increase
* how many buffers to keep in reserve
*/
reserve_count++;
flags = GFP_ATOMIC;
}
spin_unlock(&aa_buffers_lock);
if (!in_atomic)
might_sleep();
aa_buf = kmalloc(aa_g_path_max, flags);
if (!aa_buf) {
if (try_again) {
try_again = false;
goto retry;
}
pr_warn_once("AppArmor: Failed to allocate a memory buffer.\n");
return NULL;
}
return &aa_buf->buffer[0];
}
void aa_put_buffer(char *buf)
{
union aa_buffer *aa_buf;
if (!buf)
return;
aa_buf = container_of(buf, union aa_buffer, buffer[0]);
spin_lock(&aa_buffers_lock);
list_add(&aa_buf->list, &aa_global_buffers);
buffer_count++;
spin_unlock(&aa_buffers_lock);
}
/*
* 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 = (__force struct cred *)current->real_cred;
set_cred_label(cred, aa_get_label(ns_unconfined(root_ns)));
return 0;
}
static void destroy_buffers(void)
{
union aa_buffer *aa_buf;
spin_lock(&aa_buffers_lock);
while (!list_empty(&aa_global_buffers)) {
aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer,
list);
list_del(&aa_buf->list);
spin_unlock(&aa_buffers_lock);
kfree(aa_buf);
spin_lock(&aa_buffers_lock);
}
spin_unlock(&aa_buffers_lock);
}
static int __init alloc_buffers(void)
{
union aa_buffer *aa_buf;
int i, num;
/*
* A function may require two buffers at once. Usually the buffers are
* used for a short period of time and are shared. On UP kernel buffers
* two should be enough, with more CPUs it is possible that more
* buffers will be used simultaneously. The preallocated pool may grow.
* This preallocation has also the side-effect that AppArmor will be
* disabled early at boot if aa_g_path_max is extremly high.
*/
if (num_online_cpus() > 1)
num = 4 + RESERVE_COUNT;
else
num = 2 + RESERVE_COUNT;
for (i = 0; i < num; i++) {
aa_buf = kmalloc(aa_g_path_max, GFP_KERNEL |
__GFP_RETRY_MAYFAIL | __GFP_NOWARN);
if (!aa_buf) {
destroy_buffers();
return -ENOMEM;
}
aa_put_buffer(&aa_buf->buffer[0]);
}
return 0;
}
#ifdef CONFIG_SYSCTL
static int apparmor_dointvec(struct ctl_table *table, int write,
void *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 */
#if defined(CONFIG_NETFILTER) && defined(CONFIG_NETWORK_SECMARK)
static unsigned int apparmor_ip_postroute(void *priv,
struct sk_buff *skb,
const struct nf_hook_state *state)
{
struct aa_sk_ctx *ctx;
struct sock *sk;
if (!skb->secmark)
return NF_ACCEPT;
sk = skb_to_full_sk(skb);
if (sk == NULL)
return NF_ACCEPT;
ctx = SK_CTX(sk);
if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND,
skb->secmark, sk))
return NF_ACCEPT;
return NF_DROP_ERR(-ECONNREFUSED);
}
static unsigned int apparmor_ipv4_postroute(void *priv,
struct sk_buff *skb,
const struct nf_hook_state *state)
{
return apparmor_ip_postroute(priv, skb, state);
}
#if IS_ENABLED(CONFIG_IPV6)
static unsigned int apparmor_ipv6_postroute(void *priv,
struct sk_buff *skb,
const struct nf_hook_state *state)
{
return apparmor_ip_postroute(priv, skb, state);
}
#endif
static const struct nf_hook_ops apparmor_nf_ops[] = {
{
.hook = apparmor_ipv4_postroute,
.pf = NFPROTO_IPV4,
.hooknum = NF_INET_POST_ROUTING,
.priority = NF_IP_PRI_SELINUX_FIRST,
},
#if IS_ENABLED(CONFIG_IPV6)
{
.hook = apparmor_ipv6_postroute,
.pf = NFPROTO_IPV6,
.hooknum = NF_INET_POST_ROUTING,
.priority = NF_IP6_PRI_SELINUX_FIRST,
},
#endif
};
static int __net_init apparmor_nf_register(struct net *net)
{
int ret;
ret = nf_register_net_hooks(net, apparmor_nf_ops,
ARRAY_SIZE(apparmor_nf_ops));
return ret;
}
static void __net_exit apparmor_nf_unregister(struct net *net)
{
nf_unregister_net_hooks(net, apparmor_nf_ops,
ARRAY_SIZE(apparmor_nf_ops));
}
static struct pernet_operations apparmor_net_ops = {
.init = apparmor_nf_register,
.exit = apparmor_nf_unregister,
};
static int __init apparmor_nf_ip_init(void)
{
int err;
if (!apparmor_enabled)
return 0;
err = register_pernet_subsys(&apparmor_net_ops);
if (err)
panic("Apparmor: register_pernet_subsys: error %d\n", err);
return 0;
}
__initcall(apparmor_nf_ip_init);
#endif
static int __init apparmor_init(void)
{
int error;
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 alloc_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;
}
DEFINE_LSM(apparmor) = {
.name = "apparmor",
.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
.enabled = &apparmor_enabled,
.blobs = &apparmor_blob_sizes,
.init = apparmor_init,
};