WSL2-Linux-Kernel/security/apparmor/lsm.c

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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>
userns: security: make capabilities relative to the user namespace - Introduce ns_capable to test for a capability in a non-default user namespace. - Teach cap_capable to handle capabilities in a non-default user namespace. The motivation is to get to the unprivileged creation of new namespaces. It looks like this gets us 90% of the way there, with only potential uid confusion issues left. I still need to handle getting all caps after creation but otherwise I think I have a good starter patch that achieves all of your goals. Changelog: 11/05/2010: [serge] add apparmor 12/14/2010: [serge] fix capabilities to created user namespaces Without this, if user serge creates a user_ns, he won't have capabilities to the user_ns he created. THis is because we were first checking whether his effective caps had the caps he needed and returning -EPERM if not, and THEN checking whether he was the creator. Reverse those checks. 12/16/2010: [serge] security_real_capable needs ns argument in !security case 01/11/2011: [serge] add task_ns_capable helper 01/11/2011: [serge] add nsown_capable() helper per Bastian Blank suggestion 02/16/2011: [serge] fix a logic bug: the root user is always creator of init_user_ns, but should not always have capabilities to it! Fix the check in cap_capable(). 02/21/2011: Add the required user_ns parameter to security_capable, fixing a compile failure. 02/23/2011: Convert some macros to functions as per akpm comments. Some couldn't be converted because we can't easily forward-declare them (they are inline if !SECURITY, extern if SECURITY). Add a current_user_ns function so we can use it in capability.h without #including cred.h. Move all forward declarations together to the top of the #ifdef __KERNEL__ section, and use kernel-doc format. 02/23/2011: Per dhowells, clean up comment in cap_capable(). 02/23/2011: Per akpm, remove unreachable 'return -EPERM' in cap_capable. (Original written and signed off by Eric; latest, modified version acked by him) [akpm@linux-foundation.org: fix build] [akpm@linux-foundation.org: export current_user_ns() for ecryptfs] [serge.hallyn@canonical.com: remove unneeded extra argument in selinux's task_has_capability] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Daniel Lezcano <daniel.lezcano@free.fr> Acked-by: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-24 02:43:17 +03:00
#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"
apparmor: add mount mediation Add basic mount mediation. That allows controlling based on basic mount parameters. It does not include special mount parameters for apparmor, super block labeling, or any triggers for apparmor namespace parameter modifications on pivot root. default userspace policy rules have the form of MOUNT RULE = ( MOUNT | REMOUNT | UMOUNT ) MOUNT = [ QUALIFIERS ] 'mount' [ MOUNT CONDITIONS ] [ SOURCE FILEGLOB ] [ '->' MOUNTPOINT FILEGLOB ] REMOUNT = [ QUALIFIERS ] 'remount' [ MOUNT CONDITIONS ] MOUNTPOINT FILEGLOB UMOUNT = [ QUALIFIERS ] 'umount' [ MOUNT CONDITIONS ] MOUNTPOINT FILEGLOB MOUNT CONDITIONS = [ ( 'fstype' | 'vfstype' ) ( '=' | 'in' ) MOUNT FSTYPE EXPRESSION ] [ 'options' ( '=' | 'in' ) MOUNT FLAGS EXPRESSION ] MOUNT FSTYPE EXPRESSION = ( MOUNT FSTYPE LIST | MOUNT EXPRESSION ) MOUNT FSTYPE LIST = Comma separated list of valid filesystem and virtual filesystem types (eg ext4, debugfs, etc) MOUNT FLAGS EXPRESSION = ( MOUNT FLAGS LIST | MOUNT EXPRESSION ) MOUNT FLAGS LIST = Comma separated list of MOUNT FLAGS. MOUNT FLAGS = ( 'ro' | 'rw' | 'nosuid' | 'suid' | 'nodev' | 'dev' | 'noexec' | 'exec' | 'sync' | 'async' | 'remount' | 'mand' | 'nomand' | 'dirsync' | 'noatime' | 'atime' | 'nodiratime' | 'diratime' | 'bind' | 'rbind' | 'move' | 'verbose' | 'silent' | 'loud' | 'acl' | 'noacl' | 'unbindable' | 'runbindable' | 'private' | 'rprivate' | 'slave' | 'rslave' | 'shared' | 'rshared' | 'relatime' | 'norelatime' | 'iversion' | 'noiversion' | 'strictatime' | 'nouser' | 'user' ) MOUNT EXPRESSION = ( ALPHANUMERIC | AARE ) ... PIVOT ROOT RULE = [ QUALIFIERS ] pivot_root [ oldroot=OLD PUT FILEGLOB ] [ NEW ROOT FILEGLOB ] SOURCE FILEGLOB = FILEGLOB MOUNTPOINT FILEGLOB = FILEGLOB eg. mount, mount /dev/foo, mount options=ro /dev/foo -> /mnt/, mount options in (ro,atime) /dev/foo -> /mnt/, mount options=ro options=atime, Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-07-19 09:04:47 +03:00
#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);
}
apparmor: add mount mediation Add basic mount mediation. That allows controlling based on basic mount parameters. It does not include special mount parameters for apparmor, super block labeling, or any triggers for apparmor namespace parameter modifications on pivot root. default userspace policy rules have the form of MOUNT RULE = ( MOUNT | REMOUNT | UMOUNT ) MOUNT = [ QUALIFIERS ] 'mount' [ MOUNT CONDITIONS ] [ SOURCE FILEGLOB ] [ '->' MOUNTPOINT FILEGLOB ] REMOUNT = [ QUALIFIERS ] 'remount' [ MOUNT CONDITIONS ] MOUNTPOINT FILEGLOB UMOUNT = [ QUALIFIERS ] 'umount' [ MOUNT CONDITIONS ] MOUNTPOINT FILEGLOB MOUNT CONDITIONS = [ ( 'fstype' | 'vfstype' ) ( '=' | 'in' ) MOUNT FSTYPE EXPRESSION ] [ 'options' ( '=' | 'in' ) MOUNT FLAGS EXPRESSION ] MOUNT FSTYPE EXPRESSION = ( MOUNT FSTYPE LIST | MOUNT EXPRESSION ) MOUNT FSTYPE LIST = Comma separated list of valid filesystem and virtual filesystem types (eg ext4, debugfs, etc) MOUNT FLAGS EXPRESSION = ( MOUNT FLAGS LIST | MOUNT EXPRESSION ) MOUNT FLAGS LIST = Comma separated list of MOUNT FLAGS. MOUNT FLAGS = ( 'ro' | 'rw' | 'nosuid' | 'suid' | 'nodev' | 'dev' | 'noexec' | 'exec' | 'sync' | 'async' | 'remount' | 'mand' | 'nomand' | 'dirsync' | 'noatime' | 'atime' | 'nodiratime' | 'diratime' | 'bind' | 'rbind' | 'move' | 'verbose' | 'silent' | 'loud' | 'acl' | 'noacl' | 'unbindable' | 'runbindable' | 'private' | 'rprivate' | 'slave' | 'rslave' | 'shared' | 'rshared' | 'relatime' | 'norelatime' | 'iversion' | 'noiversion' | 'strictatime' | 'nouser' | 'user' ) MOUNT EXPRESSION = ( ALPHANUMERIC | AARE ) ... PIVOT ROOT RULE = [ QUALIFIERS ] pivot_root [ oldroot=OLD PUT FILEGLOB ] [ NEW ROOT FILEGLOB ] SOURCE FILEGLOB = FILEGLOB MOUNTPOINT FILEGLOB = FILEGLOB eg. mount, mount /dev/foo, mount options=ro /dev/foo -> /mnt/, mount options in (ro,atime) /dev/foo -> /mnt/, mount options=ro options=atime, Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-07-19 09:04:47 +03:00
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),
apparmor: add mount mediation Add basic mount mediation. That allows controlling based on basic mount parameters. It does not include special mount parameters for apparmor, super block labeling, or any triggers for apparmor namespace parameter modifications on pivot root. default userspace policy rules have the form of MOUNT RULE = ( MOUNT | REMOUNT | UMOUNT ) MOUNT = [ QUALIFIERS ] 'mount' [ MOUNT CONDITIONS ] [ SOURCE FILEGLOB ] [ '->' MOUNTPOINT FILEGLOB ] REMOUNT = [ QUALIFIERS ] 'remount' [ MOUNT CONDITIONS ] MOUNTPOINT FILEGLOB UMOUNT = [ QUALIFIERS ] 'umount' [ MOUNT CONDITIONS ] MOUNTPOINT FILEGLOB MOUNT CONDITIONS = [ ( 'fstype' | 'vfstype' ) ( '=' | 'in' ) MOUNT FSTYPE EXPRESSION ] [ 'options' ( '=' | 'in' ) MOUNT FLAGS EXPRESSION ] MOUNT FSTYPE EXPRESSION = ( MOUNT FSTYPE LIST | MOUNT EXPRESSION ) MOUNT FSTYPE LIST = Comma separated list of valid filesystem and virtual filesystem types (eg ext4, debugfs, etc) MOUNT FLAGS EXPRESSION = ( MOUNT FLAGS LIST | MOUNT EXPRESSION ) MOUNT FLAGS LIST = Comma separated list of MOUNT FLAGS. MOUNT FLAGS = ( 'ro' | 'rw' | 'nosuid' | 'suid' | 'nodev' | 'dev' | 'noexec' | 'exec' | 'sync' | 'async' | 'remount' | 'mand' | 'nomand' | 'dirsync' | 'noatime' | 'atime' | 'nodiratime' | 'diratime' | 'bind' | 'rbind' | 'move' | 'verbose' | 'silent' | 'loud' | 'acl' | 'noacl' | 'unbindable' | 'runbindable' | 'private' | 'rprivate' | 'slave' | 'rslave' | 'shared' | 'rshared' | 'relatime' | 'norelatime' | 'iversion' | 'noiversion' | 'strictatime' | 'nouser' | 'user' ) MOUNT EXPRESSION = ( ALPHANUMERIC | AARE ) ... PIVOT ROOT RULE = [ QUALIFIERS ] pivot_root [ oldroot=OLD PUT FILEGLOB ] [ NEW ROOT FILEGLOB ] SOURCE FILEGLOB = FILEGLOB MOUNTPOINT FILEGLOB = FILEGLOB eg. mount, mount /dev/foo, mount options=ro /dev/foo -> /mnt/, mount options in (ro,atime) /dev/foo -> /mnt/, mount options=ro options=atime, Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-07-19 09:04:47 +03:00
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;
apparmor: Make path_max parameter readonly The path_max parameter determines the max size of buffers allocated but it should not be setable at run time. If can be used to cause an oops root@ubuntu:~# echo 16777216 > /sys/module/apparmor/parameters/path_max root@ubuntu:~# cat /sys/module/apparmor/parameters/path_max Killed [ 122.141911] BUG: unable to handle kernel paging request at ffff880080945fff [ 122.143497] IP: [<ffffffff81228844>] d_absolute_path+0x44/0xa0 [ 122.144742] PGD 220c067 PUD 0 [ 122.145453] Oops: 0002 [#1] SMP [ 122.146204] Modules linked in: vmw_vsock_vmci_transport vsock ppdev vmw_balloon snd_ens1371 btusb snd_ac97_codec gameport snd_rawmidi btrtl snd_seq_device ac97_bus btbcm btintel snd_pcm input_leds bluetooth snd_timer snd joydev soundcore serio_raw coretemp shpchp nfit parport_pc i2c_piix4 8250_fintek vmw_vmci parport mac_hid ib_iser rdma_cm iw_cm ib_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear hid_generic usbhid hid crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd vmwgfx psmouse mptspi ttm mptscsih drm_kms_helper mptbase syscopyarea scsi_transport_spi sysfillrect [ 122.163365] ahci sysimgblt e1000 fb_sys_fops libahci drm pata_acpi fjes [ 122.164747] CPU: 3 PID: 1501 Comm: bash Not tainted 4.4.0-59-generic #80-Ubuntu [ 122.166250] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015 [ 122.168611] task: ffff88003496aa00 ti: ffff880076474000 task.ti: ffff880076474000 [ 122.170018] RIP: 0010:[<ffffffff81228844>] [<ffffffff81228844>] d_absolute_path+0x44/0xa0 [ 122.171525] RSP: 0018:ffff880076477b90 EFLAGS: 00010206 [ 122.172462] RAX: ffff880080945fff RBX: 0000000000000000 RCX: 0000000001000000 [ 122.173709] RDX: 0000000000ffffff RSI: ffff880080946000 RDI: ffff8800348a1010 [ 122.174978] RBP: ffff880076477bb8 R08: ffff880076477c80 R09: 0000000000000000 [ 122.176227] R10: 00007ffffffff000 R11: ffff88007f946000 R12: ffff88007f946000 [ 122.177496] R13: ffff880076477c80 R14: ffff8800348a1010 R15: ffff8800348a2400 [ 122.178745] FS: 00007fd459eb4700(0000) GS:ffff88007b6c0000(0000) knlGS:0000000000000000 [ 122.180176] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 122.181186] CR2: ffff880080945fff CR3: 0000000073422000 CR4: 00000000001406e0 [ 122.182469] Stack: [ 122.182843] 00ffffff00000001 ffff880080946000 0000000000000000 0000000000000000 [ 122.184409] 00000000570f789c ffff880076477c30 ffffffff81385671 ffff88007a2e7a58 [ 122.185810] 0000000000000000 ffff880076477c88 01000000008a1000 0000000000000000 [ 122.187231] Call Trace: [ 122.187680] [<ffffffff81385671>] aa_path_name+0x81/0x370 [ 122.188637] [<ffffffff813875dd>] profile_transition+0xbd/0xb80 [ 122.190181] [<ffffffff811af9bc>] ? zone_statistics+0x7c/0xa0 [ 122.191674] [<ffffffff81389b20>] apparmor_bprm_set_creds+0x9b0/0xac0 [ 122.193288] [<ffffffff812e1971>] ? ext4_xattr_get+0x81/0x220 [ 122.194793] [<ffffffff812e800c>] ? ext4_xattr_security_get+0x1c/0x30 [ 122.196392] [<ffffffff813449b9>] ? get_vfs_caps_from_disk+0x69/0x110 [ 122.198004] [<ffffffff81232d4f>] ? mnt_may_suid+0x3f/0x50 [ 122.199737] [<ffffffff81344b03>] ? cap_bprm_set_creds+0xa3/0x600 [ 122.201377] [<ffffffff81346e53>] security_bprm_set_creds+0x33/0x50 [ 122.203024] [<ffffffff81214ce5>] prepare_binprm+0x85/0x190 [ 122.204515] [<ffffffff81216545>] do_execveat_common.isra.33+0x485/0x710 [ 122.206200] [<ffffffff81216a6a>] SyS_execve+0x3a/0x50 [ 122.207615] [<ffffffff81838795>] stub_execve+0x5/0x5 [ 122.208978] [<ffffffff818384f2>] ? entry_SYSCALL_64_fastpath+0x16/0x71 [ 122.210615] Code: f8 31 c0 48 63 c2 83 ea 01 48 c7 45 e8 00 00 00 00 48 01 c6 85 d2 48 c7 45 f0 00 00 00 00 48 89 75 e0 89 55 dc 78 0c 48 8d 46 ff <c6> 46 ff 00 48 89 45 e0 48 8d 55 e0 48 8d 4d dc 48 8d 75 e8 e8 [ 122.217320] RIP [<ffffffff81228844>] d_absolute_path+0x44/0xa0 [ 122.218860] RSP <ffff880076477b90> [ 122.219919] CR2: ffff880080945fff [ 122.220936] ---[ end trace 506cdbd85eb6c55e ]--- Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-04-06 16:55:24 +03:00
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);