cregit-Linux how code gets into the kernel

Release 4.10 security/apparmor/context.c

/*
 * AppArmor security module
 *
 * This file contains AppArmor functions used to manipulate object security
 * contexts.
 *
 * 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.
 *
 *
 * AppArmor sets confinement on every task, via the the aa_task_cxt and
 * the aa_task_cxt.profile, both of which are required and are not allowed
 * to be NULL.  The aa_task_cxt is not reference counted and is unique
 * to each cred (which is reference count).  The profile pointed to by
 * the task_cxt is reference counted.
 *
 * TODO
 * If a task uses change_hat it currently does not return to the old
 * cred or task context but instead creates a new one.  Ideally the task
 * should return to the previous cred if it has not been modified.
 *
 */

#include "include/context.h"
#include "include/policy.h"

/**
 * aa_alloc_task_context - allocate a new task_cxt
 * @flags: gfp flags for allocation
 *
 * Returns: allocated buffer or NULL on failure
 */

struct aa_task_cxt *aa_alloc_task_context(gfp_t flags) { return kzalloc(sizeof(struct aa_task_cxt), flags); }

Contributors

PersonTokensPropCommitsCommitProp
john johansenjohn johansen22100.00%1100.00%
Total22100.00%1100.00%

/** * aa_free_task_context - free a task_cxt * @cxt: task_cxt to free (MAYBE NULL) */
void aa_free_task_context(struct aa_task_cxt *cxt) { if (cxt) { aa_put_profile(cxt->profile); aa_put_profile(cxt->previous); aa_put_profile(cxt->onexec); kzfree(cxt); } }

Contributors

PersonTokensPropCommitsCommitProp
john johansenjohn johansen42100.00%1100.00%
Total42100.00%1100.00%

/** * aa_dup_task_context - duplicate a task context, incrementing reference counts * @new: a blank task context (NOT NULL) * @old: the task context to copy (NOT NULL) */
void aa_dup_task_context(struct aa_task_cxt *new, const struct aa_task_cxt *old) { *new = *old; aa_get_profile(new->profile); aa_get_profile(new->previous); aa_get_profile(new->onexec); }

Contributors

PersonTokensPropCommitsCommitProp
john johansenjohn johansen43100.00%1100.00%
Total43100.00%1100.00%

/** * aa_get_task_profile - Get another task's profile * @task: task to query (NOT NULL) * * Returns: counted reference to @task's profile */
struct aa_profile *aa_get_task_profile(struct task_struct *task) { struct aa_profile *p; rcu_read_lock(); p = aa_get_profile(__aa_task_profile(task)); rcu_read_unlock(); return p; }

Contributors

PersonTokensPropCommitsCommitProp
john johansenjohn johansen36100.00%1100.00%
Total36100.00%1100.00%

/** * aa_replace_current_profile - replace the current tasks profiles * @profile: new profile (NOT NULL) * * Returns: 0 or error on failure */
int aa_replace_current_profile(struct aa_profile *profile) { struct aa_task_cxt *cxt = current_cxt(); struct cred *new; BUG_ON(!profile); if (cxt->profile == profile) return 0; new = prepare_creds(); if (!new) return -ENOMEM; cxt = cred_cxt(new); if (unconfined(profile) || (cxt->profile->ns != profile->ns)) /* if switching to unconfined or a different profile namespace * clear out context state */ aa_clear_task_cxt_trans(cxt); /* be careful switching cxt->profile, when racing replacement it * is possible that cxt->profile->replacedby->profile is the reference * keeping @profile valid, so make sure to get its reference before * dropping the reference on cxt->profile */ aa_get_profile(profile); aa_put_profile(cxt->profile); cxt->profile = profile; commit_creds(new); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
john johansenjohn johansen113100.00%4100.00%
Total113100.00%4100.00%

/** * aa_set_current_onexec - set the tasks change_profile to happen onexec * @profile: system profile to set at exec (MAYBE NULL to clear value) * * Returns: 0 or error on failure */
int aa_set_current_onexec(struct aa_profile *profile) { struct aa_task_cxt *cxt; struct cred *new = prepare_creds(); if (!new) return -ENOMEM; cxt = cred_cxt(new); aa_get_profile(profile); aa_put_profile(cxt->onexec); cxt->onexec = profile; commit_creds(new); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
john johansenjohn johansen65100.00%2100.00%
Total65100.00%2100.00%

/** * aa_set_current_hat - set the current tasks hat * @profile: profile to set as the current hat (NOT NULL) * @token: token value that must be specified to change from the hat * * Do switch of tasks hat. If the task is currently in a hat * validate the token to match. * * Returns: 0 or error on failure */
int aa_set_current_hat(struct aa_profile *profile, u64 token) { struct aa_task_cxt *cxt; struct cred *new = prepare_creds(); if (!new) return -ENOMEM; BUG_ON(!profile); cxt = cred_cxt(new); if (!cxt->previous) { /* transfer refcount */ cxt->previous = cxt->profile; cxt->token = token; } else if (cxt->token == token) { aa_put_profile(cxt->profile); } else { /* previous_profile && cxt->token != token */ abort_creds(new); return -EACCES; } cxt->profile = aa_get_newest_profile(profile); /* clear exec on switching context */ aa_put_profile(cxt->onexec); cxt->onexec = NULL; commit_creds(new); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
john johansenjohn johansen134100.00%3100.00%
Total134100.00%3100.00%

/** * aa_restore_previous_profile - exit from hat context restoring the profile * @token: the token that must be matched to exit hat context * * Attempt to return out of a hat to the previous profile. The token * must match the stored token value. * * Returns: 0 or error of failure */
int aa_restore_previous_profile(u64 token) { struct aa_task_cxt *cxt; struct cred *new = prepare_creds(); if (!new) return -ENOMEM; cxt = cred_cxt(new); if (cxt->token != token) { abort_creds(new); return -EACCES; } /* ignore restores when there is no saved profile */ if (!cxt->previous) { abort_creds(new); return 0; } aa_put_profile(cxt->profile); cxt->profile = aa_get_newest_profile(cxt->previous); BUG_ON(!cxt->profile); /* clear exec && prev information when restoring to previous context */ aa_clear_task_cxt_trans(cxt); commit_creds(new); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
john johansenjohn johansen114100.00%4100.00%
Total114100.00%4100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
john johansenjohn johansen584100.00%5100.00%
Total584100.00%5100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.