/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #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/label.h" #include "include/policy.h" #include "include/policy_ns.h" #include "include/procattr.h" #include "include/mount.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, current_task_ctx()); 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, const struct cred *cred) { 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(cred); if (!unconfined(label)) { struct inode *inode = file_inode(file); struct path_cond cond = { inode->i_uid, inode->i_mode }; error = aa_path_perm(OP_OPEN, label, &file->f_path, 0, aa_map_file_to_perms(file), &cond); /* todo cache full allowed permissions set and state */ fctx->allow = aa_map_file_to_perms(file); } aa_put_label(label); return error; } static int apparmor_file_alloc_security(struct file *file) { int error = 0; /* freed by apparmor_file_free_security */ struct aa_label *label = begin_current_label_crit_section(); file->f_security = aa_alloc_file_ctx(label, GFP_KERNEL); if (!file_ctx(file)) error = -ENOMEM; end_current_label_crit_section(label); return error; } static void apparmor_file_free_security(struct file *file) { aa_free_file_ctx(file_ctx(file)); } static int common_file_perm(const char *op, struct file *file, u32 mask) { struct aa_label *label; int error = 0; /* don't reaudit files closed during inheritance */ if (file->f_path.dentry == aa_null.dentry) return -EACCES; label = __begin_current_label_crit_section(); error = aa_file_perm(op, label, file, mask); __end_current_label_crit_section(label); return error; } static int apparmor_file_receive(struct file *file) { return common_file_perm(OP_FRECEIVE, file, aa_map_file_to_perms(file)); } static int apparmor_file_permission(struct file *file, int mask) { return common_file_perm(OP_FPERM, file, mask); } static int apparmor_file_lock(struct file *file, unsigned int cmd) { u32 mask = AA_MAY_LOCK; if (cmd == F_WRLCK) mask |= MAY_WRITE; return common_file_perm(OP_FLOCK, file, mask); } static int common_mmap(const char *op, struct file *file, unsigned long prot, unsigned long flags) { int mask = 0; if (!file || !file_ctx(file)) return 0; if (prot & PROT_READ) mask |= MAY_READ; /* * Private mappings don't require write perms since they don't * write back to the files */ if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE)) mask |= MAY_WRITE; if (prot & PROT_EXEC) mask |= AA_EXEC_MMAP; return common_file_perm(op, file, mask); } static int apparmor_mmap_file(struct file *file, unsigned long reqprot, unsigned long prot, unsigned long flags) { return common_mmap(OP_FMMAP, file, prot, flags); } static int apparmor_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot, unsigned long prot) { return common_mmap(OP_FMPROT, vma->vm_file, prot, !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0); } static int apparmor_sb_mount(const char *dev_name, const struct path *path, const char *type, unsigned long flags, void *data) { struct aa_label *label; int error = 0; /* Discard magic */ if ((flags & MS_MGC_MSK) == MS_MGC_VAL) flags &= ~MS_MGC_MSK; flags &= ~AA_MS_IGNORE_MASK; label = __begin_current_label_crit_section(); if (!unconfined(label)) { if (flags & MS_REMOUNT) error = aa_remount(label, path, flags, data); else if (flags & MS_BIND) error = aa_bind_mount(label, path, dev_name, flags); else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE)) error = aa_mount_change_type(label, path, flags); else if (flags & MS_MOVE) error = aa_move_mount(label, path, dev_name); else error = aa_new_mount(label, dev_name, path, type, flags, data); } __end_current_label_crit_section(label); return error; } static int apparmor_sb_umount(struct vfsmount *mnt, int flags) { struct aa_label *label; int error = 0; label = __begin_current_label_crit_section(); if (!unconfined(label)) error = aa_umount(label, mnt, flags); __end_current_label_crit_section(label); return error; } static int apparmor_sb_pivotroot(const struct path *old_path, const struct path *new_path) { struct aa_label *label; int error = 0; label = aa_get_current_label(); if (!unconfined(label)) error = aa_pivotroot(label, old_path, new_path); aa_put_label(label); return error; } static int apparmor_getprocattr(struct task_struct *task, char *name, char **value) { int error = -ENOENT; /* released below */ const struct cred *cred = get_task_cred(task); struct aa_task_ctx *ctx = current_task_ctx(); 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(current_task_ctx()); return; } 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, u32 secid) { struct aa_label *cl, *tl; int error; if (secid) /* TODO: after secid to label mapping is done. * Dealing with USB IO specific behavior */ return 0; 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; } 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(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_setrlimit, apparmor_task_setrlimit), LSM_HOOK_INIT(task_kill, apparmor_task_kill), }; /* * AppArmor sysfs module parameters */ static int param_set_aabool(const char *val, const struct kernel_param *kp); static int param_get_aabool(char *buffer, const struct kernel_param *kp); #define param_check_aabool param_check_bool static const struct kernel_param_ops param_ops_aabool = { .flags = KERNEL_PARAM_OPS_FL_NOARG, .set = param_set_aabool, .get = param_get_aabool }; static int param_set_aauint(const char *val, const struct kernel_param *kp); static int param_get_aauint(char *buffer, const struct kernel_param *kp); #define param_check_aauint param_check_uint static const struct kernel_param_ops param_ops_aauint = { .set = param_set_aauint, .get = param_get_aauint }; static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp); static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp); #define param_check_aalockpolicy param_check_bool static const struct kernel_param_ops param_ops_aalockpolicy = { .flags = KERNEL_PARAM_OPS_FL_NOARG, .set = param_set_aalockpolicy, .get = param_get_aalockpolicy }; static int param_set_audit(const char *val, const struct kernel_param *kp); static int param_get_audit(char *buffer, const struct kernel_param *kp); static int param_set_mode(const char *val, const struct kernel_param *kp); static int param_get_mode(char *buffer, const struct kernel_param *kp); /* Flag values, also controllable via /sys/module/apparmor/parameters * We define special types as we want to do additional mediation. */ /* AppArmor global enforcement switch - complain, enforce, kill */ enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE; module_param_call(mode, param_set_mode, param_get_mode, &aa_g_profile_mode, S_IRUSR | S_IWUSR); /* whether policy verification hashing is enabled */ bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT); #ifdef CONFIG_SECURITY_APPARMOR_HASH module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR); #endif /* Debug mode */ bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_APPARMOR_DEBUG_MESSAGES); module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR); /* Audit mode */ enum audit_mode aa_g_audit; module_param_call(audit, param_set_audit, param_get_audit, &aa_g_audit, S_IRUSR | S_IWUSR); /* Determines if audit header is included in audited messages. This * provides more context if the audit daemon is not running */ bool aa_g_audit_header = true; module_param_named(audit_header, aa_g_audit_header, aabool, S_IRUSR | S_IWUSR); /* lock out loading/removal of policy * TODO: add in at boot loading of policy, which is the only way to * load policy, if lock_policy is set */ bool aa_g_lock_policy; module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy, S_IRUSR | S_IWUSR); /* Syscall logging mode */ bool aa_g_logsyscall; module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR); /* Maximum pathname length before accesses will start getting rejected */ unsigned int aa_g_path_max = 2 * PATH_MAX; module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR); /* Determines how paranoid loading of policy is and how much verification * on the loaded policy is done. * DEPRECATED: read only as strict checking of load is always done now * that none root users (user namespaces) can load policy. */ bool aa_g_paranoid_load = true; module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO); /* Boot time disable flag */ static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE; module_param_named(enabled, apparmor_enabled, bool, S_IRUGO); static int __init apparmor_enabled_setup(char *str) { unsigned long enabled; int error = kstrtoul(str, 0, &enabled); if (!error) apparmor_enabled = enabled ? 1 : 0; return 1; } __setup("apparmor=", apparmor_enabled_setup); /* set global flag turning off the ability to load policy */ static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp) { if (!apparmor_enabled) return -EINVAL; if (apparmor_initialized && !policy_admin_capable(NULL)) return -EPERM; return param_set_bool(val, kp); } static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp) { if (!apparmor_enabled) return -EINVAL; if (apparmor_initialized && !policy_view_capable(NULL)) return -EPERM; return param_get_bool(buffer, kp); } static int param_set_aabool(const char *val, const struct kernel_param *kp) { if (!apparmor_enabled) return -EINVAL; if (apparmor_initialized && !policy_admin_capable(NULL)) return -EPERM; return param_set_bool(val, kp); } static int param_get_aabool(char *buffer, const struct kernel_param *kp) { if (!apparmor_enabled) return -EINVAL; if (apparmor_initialized && !policy_view_capable(NULL)) return -EPERM; return param_get_bool(buffer, kp); } static int param_set_aauint(const char *val, const struct kernel_param *kp) { int error; if (!apparmor_enabled) return -EINVAL; /* file is ro but enforce 2nd line check */ if (apparmor_initialized) return -EPERM; error = param_set_uint(val, kp); pr_info("AppArmor: buffer size set to %d bytes\n", aa_g_path_max); return error; } static int param_get_aauint(char *buffer, const struct kernel_param *kp) { if (!apparmor_enabled) return -EINVAL; if (apparmor_initialized && !policy_view_capable(NULL)) return -EPERM; return param_get_uint(buffer, kp); } static int param_get_audit(char *buffer, const struct kernel_param *kp) { if (!apparmor_enabled) return -EINVAL; if (apparmor_initialized && !policy_view_capable(NULL)) return -EPERM; return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]); } static int param_set_audit(const char *val, const struct kernel_param *kp) { int i; if (!apparmor_enabled) return -EINVAL; if (!val) return -EINVAL; if (apparmor_initialized && !policy_admin_capable(NULL)) return -EPERM; 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, 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; 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_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; } 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);