linux/security/apparmor/lsm.c
John Johansen 622f6e3265 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>
2017-04-07 08:58:36 +10:00

1022 lines
27 KiB
C

/*
* AppArmor security module
*
* This file contains AppArmor LSM hooks.
*
* Copyright (C) 1998-2008 Novell/SUSE
* Copyright 2009-2010 Canonical Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
*/
#include <linux/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/kmemleak.h>
#include <net/sock.h>
#include "include/apparmor.h"
#include "include/apparmorfs.h"
#include "include/audit.h"
#include "include/capability.h"
#include "include/context.h"
#include "include/file.h"
#include "include/ipc.h"
#include "include/path.h"
#include "include/policy.h"
#include "include/policy_ns.h"
#include "include/procattr.h"
/* Flag indicating whether initialization completed */
int apparmor_initialized;
DEFINE_PER_CPU(struct aa_buffers, aa_buffers);
/*
* LSM hook functions
*/
/*
* free the associated aa_task_ctx and put its profiles
*/
static void apparmor_cred_free(struct cred *cred)
{
aa_free_task_context(cred_ctx(cred));
cred_ctx(cred) = NULL;
}
/*
* allocate the apparmor part of blank credentials
*/
static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
{
/* freed by apparmor_cred_free */
struct aa_task_ctx *ctx = aa_alloc_task_context(gfp);
if (!ctx)
return -ENOMEM;
cred_ctx(cred) = ctx;
return 0;
}
/*
* prepare new aa_task_ctx for modification by prepare_cred block
*/
static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
gfp_t gfp)
{
/* freed by apparmor_cred_free */
struct aa_task_ctx *ctx = aa_alloc_task_context(gfp);
if (!ctx)
return -ENOMEM;
aa_dup_task_context(ctx, cred_ctx(old));
cred_ctx(new) = ctx;
return 0;
}
/*
* transfer the apparmor data to a blank set of creds
*/
static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
{
const struct aa_task_ctx *old_ctx = cred_ctx(old);
struct aa_task_ctx *new_ctx = cred_ctx(new);
aa_dup_task_context(new_ctx, old_ctx);
}
static int apparmor_ptrace_access_check(struct task_struct *child,
unsigned int mode)
{
return aa_ptrace(current, child, mode);
}
static int apparmor_ptrace_traceme(struct task_struct *parent)
{
return aa_ptrace(parent, current, PTRACE_MODE_ATTACH);
}
/* Derived from security/commoncap.c:cap_capget */
static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
kernel_cap_t *inheritable, kernel_cap_t *permitted)
{
struct aa_profile *profile;
const struct cred *cred;
rcu_read_lock();
cred = __task_cred(target);
profile = aa_cred_profile(cred);
/*
* cap_capget is stacked ahead of this and will
* initialize effective and permitted.
*/
if (!unconfined(profile) && !COMPLAIN_MODE(profile)) {
*effective = cap_intersect(*effective, profile->caps.allow);
*permitted = cap_intersect(*permitted, profile->caps.allow);
}
rcu_read_unlock();
return 0;
}
static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
int cap, int audit)
{
struct aa_profile *profile;
int error = 0;
profile = aa_cred_profile(cred);
if (!unconfined(profile))
error = aa_capable(profile, cap, audit);
return error;
}
/**
* common_perm - basic common permission check wrapper fn for paths
* @op: operation being checked
* @path: path to check permission of (NOT NULL)
* @mask: requested permissions mask
* @cond: conditional info for the permission request (NOT NULL)
*
* Returns: %0 else error code if error or permission denied
*/
static int common_perm(const char *op, const struct path *path, u32 mask,
struct path_cond *cond)
{
struct aa_profile *profile;
int error = 0;
profile = __aa_current_profile();
if (!unconfined(profile))
error = aa_path_perm(op, profile, path, 0, mask, cond);
return error;
}
/**
* common_perm_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_META_WRITE);
}
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_profile *profile;
int error = 0;
if (!path_mediated_fs(old_dentry))
return 0;
profile = aa_current_profile();
if (!unconfined(profile))
error = aa_path_link(profile, old_dentry, new_dir, new_dentry);
return error;
}
static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_dentry,
const struct path *new_dir, struct dentry *new_dentry)
{
struct aa_profile *profile;
int error = 0;
if (!path_mediated_fs(old_dentry))
return 0;
profile = aa_current_profile();
if (!unconfined(profile)) {
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, profile, &old_path, 0,
MAY_READ | AA_MAY_META_READ | MAY_WRITE |
AA_MAY_META_WRITE | AA_MAY_DELETE,
&cond);
if (!error)
error = aa_path_perm(OP_RENAME_DEST, profile, &new_path,
0, MAY_WRITE | AA_MAY_META_WRITE |
AA_MAY_CREATE, &cond);
}
return error;
}
static int apparmor_path_chmod(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_META_READ);
}
static int apparmor_file_open(struct file *file, const struct cred *cred)
{
struct aa_file_ctx *fctx = file->f_security;
struct aa_profile *profile;
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;
}
profile = aa_cred_profile(cred);
if (!unconfined(profile)) {
struct inode *inode = file_inode(file);
struct path_cond cond = { inode->i_uid, inode->i_mode };
error = aa_path_perm(OP_OPEN, profile, &file->f_path, 0,
aa_map_file_to_perms(file), &cond);
/* todo cache full allowed permissions set and state */
fctx->allow = aa_map_file_to_perms(file);
}
return error;
}
static int apparmor_file_alloc_security(struct file *file)
{
/* freed by apparmor_file_free_security */
file->f_security = aa_alloc_file_context(GFP_KERNEL);
if (!file->f_security)
return -ENOMEM;
return 0;
}
static void apparmor_file_free_security(struct file *file)
{
struct aa_file_ctx *ctx = file->f_security;
aa_free_file_context(ctx);
}
static int common_file_perm(const char *op, struct file *file, u32 mask)
{
struct aa_file_ctx *fctx = file->f_security;
struct aa_profile *profile, *fprofile = aa_cred_profile(file->f_cred);
int error = 0;
AA_BUG(!fprofile);
if (!file->f_path.mnt ||
!path_mediated_fs(file->f_path.dentry))
return 0;
profile = __aa_current_profile();
/* revalidate access, if task is unconfined, or the cached cred
* doesn't match or if the request is for more permissions than
* was granted.
*
* Note: the test for !unconfined(fprofile) is to handle file
* delegation from unconfined tasks
*/
if (!unconfined(profile) && !unconfined(fprofile) &&
((fprofile != profile) || (mask & ~fctx->allow)))
error = aa_file_perm(op, profile, file, mask);
return error;
}
static int apparmor_file_permission(struct file *file, int mask)
{
return common_file_perm(OP_FPERM, file, mask);
}
static int apparmor_file_lock(struct file *file, unsigned int cmd)
{
u32 mask = AA_MAY_LOCK;
if (cmd == F_WRLCK)
mask |= MAY_WRITE;
return common_file_perm(OP_FLOCK, file, mask);
}
static int common_mmap(const char *op, struct file *file, unsigned long prot,
unsigned long flags)
{
int mask = 0;
if (!file || !file->f_security)
return 0;
if (prot & PROT_READ)
mask |= MAY_READ;
/*
* Private mappings don't require write perms since they don't
* write back to the files
*/
if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
mask |= MAY_WRITE;
if (prot & PROT_EXEC)
mask |= AA_EXEC_MMAP;
return common_file_perm(op, file, mask);
}
static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
unsigned long prot, unsigned long flags)
{
return common_mmap(OP_FMMAP, file, prot, flags);
}
static int apparmor_file_mprotect(struct vm_area_struct *vma,
unsigned long reqprot, unsigned long prot)
{
return common_mmap(OP_FMPROT, vma->vm_file, prot,
!(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0);
}
static int apparmor_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 = cred_ctx(cred);
struct aa_profile *profile = NULL;
if (strcmp(name, "current") == 0)
profile = aa_get_newest_profile(ctx->profile);
else if (strcmp(name, "prev") == 0 && ctx->previous)
profile = aa_get_newest_profile(ctx->previous);
else if (strcmp(name, "exec") == 0 && ctx->onexec)
profile = aa_get_newest_profile(ctx->onexec);
else
error = -EINVAL;
if (profile)
error = aa_getprocattr(profile, value);
aa_put_profile(profile);
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_DO_TEST);
} else if (strcmp(command, "permhat") == 0) {
error = aa_setprocattr_changehat(args, arg_size,
AA_DO_TEST);
} else if (strcmp(command, "changeprofile") == 0) {
error = aa_change_profile(args, !AA_ONEXEC,
!AA_DO_TEST, false);
} else if (strcmp(command, "permprofile") == 0) {
error = aa_change_profile(args, !AA_ONEXEC, AA_DO_TEST,
false);
} else
goto fail;
} else if (strcmp(name, "exec") == 0) {
if (strcmp(command, "exec") == 0)
error = aa_change_profile(args, AA_ONEXEC, !AA_DO_TEST,
false);
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)->profile = aa_current_profile();
aad(&sa)->info = name;
aad(&sa)->error = error = -EINVAL;
aa_audit_msg(AUDIT_APPARMOR_DENIED, &sa, NULL);
goto out;
}
static int apparmor_task_setrlimit(struct task_struct *task,
unsigned int resource, struct rlimit *new_rlim)
{
struct aa_profile *profile = __aa_current_profile();
int error = 0;
if (!unconfined(profile))
error = aa_task_setrlimit(profile, task, resource, new_rlim);
return error;
}
static struct security_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(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_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(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(bprm_secureexec, apparmor_bprm_secureexec),
LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit),
};
/*
* AppArmor sysfs module parameters
*/
static int param_set_aabool(const char *val, const struct kernel_param *kp);
static int param_get_aabool(char *buffer, const struct kernel_param *kp);
#define param_check_aabool 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, struct kernel_param *kp);
static int param_get_audit(char *buffer, struct kernel_param *kp);
static int param_set_mode(const char *val, struct kernel_param *kp);
static int param_get_mode(char *buffer, struct kernel_param *kp);
/* Flag values, also controllable via /sys/module/apparmor/parameters
* We define special types as we want to do additional mediation.
*/
/* AppArmor global enforcement switch - complain, enforce, kill */
enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
module_param_call(mode, param_set_mode, param_get_mode,
&aa_g_profile_mode, S_IRUSR | S_IWUSR);
/* 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 = 1;
module_param_named(audit_header, aa_g_audit_header, aabool,
S_IRUSR | S_IWUSR);
/* lock out loading/removal of policy
* TODO: add in at boot loading of policy, which is the only way to
* load policy, if lock_policy is set
*/
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 = 1;
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)
{
if (!apparmor_enabled)
return -EINVAL;
if (apparmor_initialized && !policy_admin_capable(NULL))
return -EPERM;
return param_set_uint(val, kp);
}
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, 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, struct kernel_param *kp)
{
int i;
if (!apparmor_enabled)
return -EINVAL;
if (!val)
return -EINVAL;
if (apparmor_initialized && !policy_admin_capable(NULL))
return -EPERM;
for (i = 0; i < AUDIT_MAX_INDEX; i++) {
if (strcmp(val, audit_mode_names[i]) == 0) {
aa_g_audit = i;
return 0;
}
}
return -EINVAL;
}
static int param_get_mode(char *buffer, struct kernel_param *kp)
{
if (!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, struct kernel_param *kp)
{
int i;
if (!apparmor_enabled)
return -EINVAL;
if (!val)
return -EINVAL;
if (apparmor_initialized && !policy_admin_capable(NULL))
return -EPERM;
for (i = 0; i < APPARMOR_MODE_NAMES_MAX_INDEX; i++) {
if (strcmp(val, aa_profile_mode_names[i]) == 0) {
aa_g_profile_mode = i;
return 0;
}
}
return -EINVAL;
}
/*
* 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_context(GFP_KERNEL);
if (!ctx)
return -ENOMEM;
ctx->profile = aa_get_profile(root_ns->unconfined);
cred_ctx(cred) = 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 = 0;
return 0;
}
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 = 0;
return error;
}
security_initcall(apparmor_init);