Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 665 insertions, 0 deletions

diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
new file mode 100644
index 0000000..2eb0e47
--- /dev/null
+++ b/security/keys/process_keys.c
@@ -0,0 +1,665 @@
+/* process_keys.c: management of a process's keyrings
+ *
+ * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * 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; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/keyctl.h>
+#include <linux/fs.h>
+#include <linux/err.h>
+#include <asm/uaccess.h>
+#include "internal.h"
+
+/* session keyring create vs join semaphore */
+static DECLARE_MUTEX(key_session_sem);
+
+/* the root user's tracking struct */
+struct key_user root_key_user = {
+	.usage		= ATOMIC_INIT(3),
+	.consq		= LIST_HEAD_INIT(root_key_user.consq),
+	.lock		= SPIN_LOCK_UNLOCKED,
+	.nkeys		= ATOMIC_INIT(2),
+	.nikeys		= ATOMIC_INIT(2),
+	.uid		= 0,
+};
+
+/* the root user's UID keyring */
+struct key root_user_keyring = {
+	.usage		= ATOMIC_INIT(1),
+	.serial		= 2,
+	.type		= &key_type_keyring,
+	.user		= &root_key_user,
+	.lock		= RW_LOCK_UNLOCKED,
+	.sem		= __RWSEM_INITIALIZER(root_user_keyring.sem),
+	.perm		= KEY_USR_ALL,
+	.flags		= KEY_FLAG_INSTANTIATED,
+	.description	= "_uid.0",
+#ifdef KEY_DEBUGGING
+	.magic		= KEY_DEBUG_MAGIC,
+#endif
+};
+
+/* the root user's default session keyring */
+struct key root_session_keyring = {
+	.usage		= ATOMIC_INIT(1),
+	.serial		= 1,
+	.type		= &key_type_keyring,
+	.user		= &root_key_user,
+	.lock		= RW_LOCK_UNLOCKED,
+	.sem		= __RWSEM_INITIALIZER(root_session_keyring.sem),
+	.perm		= KEY_USR_ALL,
+	.flags		= KEY_FLAG_INSTANTIATED,
+	.description	= "_uid_ses.0",
+#ifdef KEY_DEBUGGING
+	.magic		= KEY_DEBUG_MAGIC,
+#endif
+};
+
+/*****************************************************************************/
+/*
+ * allocate the keyrings to be associated with a UID
+ */
+int alloc_uid_keyring(struct user_struct *user)
+{
+	struct key *uid_keyring, *session_keyring;
+	char buf[20];
+	int ret;
+
+	/* concoct a default session keyring */
+	sprintf(buf, "_uid_ses.%u", user->uid);
+
+	session_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, 0, NULL);
+	if (IS_ERR(session_keyring)) {
+		ret = PTR_ERR(session_keyring);
+		goto error;
+	}
+
+	/* and a UID specific keyring, pointed to by the default session
+	 * keyring */
+	sprintf(buf, "_uid.%u", user->uid);
+
+	uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, 0,
+				    session_keyring);
+	if (IS_ERR(uid_keyring)) {
+		key_put(session_keyring);
+		ret = PTR_ERR(uid_keyring);
+		goto error;
+	}
+
+	/* install the keyrings */
+	user->uid_keyring = uid_keyring;
+	user->session_keyring = session_keyring;
+	ret = 0;
+
+ error:
+	return ret;
+
+} /* end alloc_uid_keyring() */
+
+/*****************************************************************************/
+/*
+ * deal with the UID changing
+ */
+void switch_uid_keyring(struct user_struct *new_user)
+{
+#if 0 /* do nothing for now */
+	struct key *old;
+
+	/* switch to the new user's session keyring if we were running under
+	 * root's default session keyring */
+	if (new_user->uid != 0 &&
+	    current->session_keyring == &root_session_keyring
+	    ) {
+		atomic_inc(&new_user->session_keyring->usage);
+
+		task_lock(current);
+		old = current->session_keyring;
+		current->session_keyring = new_user->session_keyring;
+		task_unlock(current);
+
+		key_put(old);
+	}
+#endif
+
+} /* end switch_uid_keyring() */
+
+/*****************************************************************************/
+/*
+ * install a fresh thread keyring, discarding the old one
+ */
+int install_thread_keyring(struct task_struct *tsk)
+{
+	struct key *keyring, *old;
+	char buf[20];
+	int ret;
+
+	sprintf(buf, "_tid.%u", tsk->pid);
+
+	keyring = keyring_alloc(buf, tsk->uid, tsk->gid, 1, NULL);
+	if (IS_ERR(keyring)) {
+		ret = PTR_ERR(keyring);
+		goto error;
+	}
+
+	task_lock(tsk);
+	old = tsk->thread_keyring;
+	tsk->thread_keyring = keyring;
+	task_unlock(tsk);
+
+	ret = 0;
+
+	key_put(old);
+ error:
+	return ret;
+
+} /* end install_thread_keyring() */
+
+/*****************************************************************************/
+/*
+ * make sure a process keyring is installed
+ */
+static int install_process_keyring(struct task_struct *tsk)
+{
+	unsigned long flags;
+	struct key *keyring;
+	char buf[20];
+	int ret;
+
+	if (!tsk->signal->process_keyring) {
+		sprintf(buf, "_pid.%u", tsk->tgid);
+
+		keyring = keyring_alloc(buf, tsk->uid, tsk->gid, 1, NULL);
+		if (IS_ERR(keyring)) {
+			ret = PTR_ERR(keyring);
+			goto error;
+		}
+
+		/* attach or swap keyrings */
+		spin_lock_irqsave(&tsk->sighand->siglock, flags);
+		if (!tsk->signal->process_keyring) {
+			tsk->signal->process_keyring = keyring;
+			keyring = NULL;
+		}
+		spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+
+		key_put(keyring);
+	}
+
+	ret = 0;
+ error:
+	return ret;
+
+} /* end install_process_keyring() */
+
+/*****************************************************************************/
+/*
+ * install a session keyring, discarding the old one
+ * - if a keyring is not supplied, an empty one is invented
+ */
+static int install_session_keyring(struct task_struct *tsk,
+				   struct key *keyring)
+{
+	unsigned long flags;
+	struct key *old;
+	char buf[20];
+	int ret;
+
+	/* create an empty session keyring */
+	if (!keyring) {
+		sprintf(buf, "_ses.%u", tsk->tgid);
+
+		keyring = keyring_alloc(buf, tsk->uid, tsk->gid, 1, NULL);
+		if (IS_ERR(keyring)) {
+			ret = PTR_ERR(keyring);
+			goto error;
+		}
+	}
+	else {
+		atomic_inc(&keyring->usage);
+	}
+
+	/* install the keyring */
+	spin_lock_irqsave(&tsk->sighand->siglock, flags);
+	old = tsk->signal->session_keyring;
+	tsk->signal->session_keyring = keyring;
+	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+
+	ret = 0;
+
+	key_put(old);
+ error:
+	return ret;
+
+} /* end install_session_keyring() */
+
+/*****************************************************************************/
+/*
+ * copy the keys in a thread group for fork without CLONE_THREAD
+ */
+int copy_thread_group_keys(struct task_struct *tsk)
+{
+	unsigned long flags;
+
+	key_check(current->thread_group->session_keyring);
+	key_check(current->thread_group->process_keyring);
+
+	/* no process keyring yet */
+	tsk->signal->process_keyring = NULL;
+
+	/* same session keyring */
+	spin_lock_irqsave(&current->sighand->siglock, flags);
+	tsk->signal->session_keyring =
+		key_get(current->signal->session_keyring);
+	spin_unlock_irqrestore(&current->sighand->siglock, flags);
+
+	return 0;
+
+} /* end copy_thread_group_keys() */
+
+/*****************************************************************************/
+/*
+ * copy the keys for fork
+ */
+int copy_keys(unsigned long clone_flags, struct task_struct *tsk)
+{
+	key_check(tsk->thread_keyring);
+
+	/* no thread keyring yet */
+	tsk->thread_keyring = NULL;
+	return 0;
+
+} /* end copy_keys() */
+
+/*****************************************************************************/
+/*
+ * dispose of thread group keys upon thread group destruction
+ */
+void exit_thread_group_keys(struct signal_struct *tg)
+{
+	key_put(tg->session_keyring);
+	key_put(tg->process_keyring);
+
+} /* end exit_thread_group_keys() */
+
+/*****************************************************************************/
+/*
+ * dispose of keys upon thread exit
+ */
+void exit_keys(struct task_struct *tsk)
+{
+	key_put(tsk->thread_keyring);
+
+} /* end exit_keys() */
+
+/*****************************************************************************/
+/*
+ * deal with execve()
+ */
+int exec_keys(struct task_struct *tsk)
+{
+	unsigned long flags;
+	struct key *old;
+
+	/* newly exec'd tasks don't get a thread keyring */
+	task_lock(tsk);
+	old = tsk->thread_keyring;
+	tsk->thread_keyring = NULL;
+	task_unlock(tsk);
+
+	key_put(old);
+
+	/* discard the process keyring from a newly exec'd task */
+	spin_lock_irqsave(&tsk->sighand->siglock, flags);
+	old = tsk->signal->process_keyring;
+	tsk->signal->process_keyring = NULL;
+	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+
+	key_put(old);
+
+	return 0;
+
+} /* end exec_keys() */
+
+/*****************************************************************************/
+/*
+ * deal with SUID programs
+ * - we might want to make this invent a new session keyring
+ */
+int suid_keys(struct task_struct *tsk)
+{
+	return 0;
+
+} /* end suid_keys() */
+
+/*****************************************************************************/
+/*
+ * the filesystem user ID changed
+ */
+void key_fsuid_changed(struct task_struct *tsk)
+{
+	/* update the ownership of the thread keyring */
+	if (tsk->thread_keyring) {
+		down_write(&tsk->thread_keyring->sem);
+		write_lock(&tsk->thread_keyring->lock);
+		tsk->thread_keyring->uid = tsk->fsuid;
+		write_unlock(&tsk->thread_keyring->lock);
+		up_write(&tsk->thread_keyring->sem);
+	}
+
+} /* end key_fsuid_changed() */
+
+/*****************************************************************************/
+/*
+ * the filesystem group ID changed
+ */
+void key_fsgid_changed(struct task_struct *tsk)
+{
+	/* update the ownership of the thread keyring */
+	if (tsk->thread_keyring) {
+		down_write(&tsk->thread_keyring->sem);
+		write_lock(&tsk->thread_keyring->lock);
+		tsk->thread_keyring->gid = tsk->fsgid;
+		write_unlock(&tsk->thread_keyring->lock);
+		up_write(&tsk->thread_keyring->sem);
+	}
+
+} /* end key_fsgid_changed() */
+
+/*****************************************************************************/
+/*
+ * search the process keyrings for the first matching key
+ * - we use the supplied match function to see if the description (or other
+ *   feature of interest) matches
+ * - we return -EAGAIN if we didn't find any matching key
+ * - we return -ENOKEY if we found only negative matching keys
+ */
+struct key *search_process_keyrings_aux(struct key_type *type,
+					const void *description,
+					key_match_func_t match)
+{
+	struct task_struct *tsk = current;
+	unsigned long flags;
+	struct key *key, *ret, *err, *tmp;
+
+	/* we want to return -EAGAIN or -ENOKEY if any of the keyrings were
+	 * searchable, but we failed to find a key or we found a negative key;
+	 * otherwise we want to return a sample error (probably -EACCES) if
+	 * none of the keyrings were searchable
+	 *
+	 * in terms of priority: success > -ENOKEY > -EAGAIN > other error
+	 */
+	key = NULL;
+	ret = NULL;
+	err = ERR_PTR(-EAGAIN);
+
+	/* search the thread keyring first */
+	if (tsk->thread_keyring) {
+		key = keyring_search_aux(tsk->thread_keyring, type,
+					 description, match);
+		if (!IS_ERR(key))
+			goto found;
+
+		switch (PTR_ERR(key)) {
+		case -EAGAIN: /* no key */
+			if (ret)
+				break;
+		case -ENOKEY: /* negative key */
+			ret = key;
+			break;
+		default:
+			err = key;
+			break;
+		}
+	}
+
+	/* search the process keyring second */
+	if (tsk->signal->process_keyring) {
+		key = keyring_search_aux(tsk->signal->process_keyring,
+					 type, description, match);
+		if (!IS_ERR(key))
+			goto found;
+
+		switch (PTR_ERR(key)) {
+		case -EAGAIN: /* no key */
+			if (ret)
+				break;
+		case -ENOKEY: /* negative key */
+			ret = key;
+			break;
+		default:
+			err = key;
+			break;
+		}
+	}
+
+	/* search the session keyring last */
+	spin_lock_irqsave(&tsk->sighand->siglock, flags);
+
+	tmp = tsk->signal->session_keyring;
+	if (!tmp)
+		tmp = tsk->user->session_keyring;
+	atomic_inc(&tmp->usage);
+
+	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+
+	key = keyring_search_aux(tmp, type, description, match);
+	key_put(tmp);
+	if (!IS_ERR(key))
+		goto found;
+
+	switch (PTR_ERR(key)) {
+	case -EAGAIN: /* no key */
+		if (ret)
+			break;
+	case -ENOKEY: /* negative key */
+		ret = key;
+		break;
+	default:
+		err = key;
+		break;
+	}
+
+	/* no key - decide on the error we're going to go for */
+	key = ret ? ret : err;
+
+ found:
+	return key;
+
+} /* end search_process_keyrings_aux() */
+
+/*****************************************************************************/
+/*
+ * search the process keyrings for the first matching key
+ * - we return -EAGAIN if we didn't find any matching key
+ * - we return -ENOKEY if we found only negative matching keys
+ */
+struct key *search_process_keyrings(struct key_type *type,
+				    const char *description)
+{
+	return search_process_keyrings_aux(type, description, type->match);
+
+} /* end search_process_keyrings() */
+
+/*****************************************************************************/
+/*
+ * lookup a key given a key ID from userspace with a given permissions mask
+ * - don't create special keyrings unless so requested
+ * - partially constructed keys aren't found unless requested
+ */
+struct key *lookup_user_key(key_serial_t id, int create, int partial,
+			    key_perm_t perm)
+{
+	struct task_struct *tsk = current;
+	unsigned long flags;
+	struct key *key;
+	int ret;
+
+	key = ERR_PTR(-ENOKEY);
+
+	switch (id) {
+	case KEY_SPEC_THREAD_KEYRING:
+		if (!tsk->thread_keyring) {
+			if (!create)
+				goto error;
+
+			ret = install_thread_keyring(tsk);
+			if (ret < 0) {
+				key = ERR_PTR(ret);
+				goto error;
+			}
+		}
+
+		key = tsk->thread_keyring;
+		atomic_inc(&key->usage);
+		break;
+
+	case KEY_SPEC_PROCESS_KEYRING:
+		if (!tsk->signal->process_keyring) {
+			if (!create)
+				goto error;
+
+			ret = install_process_keyring(tsk);
+			if (ret < 0) {
+				key = ERR_PTR(ret);
+				goto error;
+			}
+		}
+
+		key = tsk->signal->process_keyring;
+		atomic_inc(&key->usage);
+		break;
+
+	case KEY_SPEC_SESSION_KEYRING:
+		if (!tsk->signal->session_keyring) {
+			/* always install a session keyring upon access if one
+			 * doesn't exist yet */
+			ret = install_session_keyring(
+			       tsk, tsk->user->session_keyring);
+			if (ret < 0)
+				goto error;
+		}
+
+		spin_lock_irqsave(&tsk->sighand->siglock, flags);
+		key = tsk->signal->session_keyring;
+		atomic_inc(&key->usage);
+		spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+		break;
+
+	case KEY_SPEC_USER_KEYRING:
+		key = tsk->user->uid_keyring;
+		atomic_inc(&key->usage);
+		break;
+
+	case KEY_SPEC_USER_SESSION_KEYRING:
+		key = tsk->user->session_keyring;
+		atomic_inc(&key->usage);
+		break;
+
+	case KEY_SPEC_GROUP_KEYRING:
+		/* group keyrings are not yet supported */
+		key = ERR_PTR(-EINVAL);
+		goto error;
+
+	default:
+		key = ERR_PTR(-EINVAL);
+		if (id < 1)
+			goto error;
+
+		key = key_lookup(id);
+		if (IS_ERR(key))
+			goto error;
+		break;
+	}
+
+	/* check the status and permissions */
+	if (perm) {
+		ret = key_validate(key);
+		if (ret < 0)
+			goto invalid_key;
+	}
+
+	ret = -EIO;
+	if (!partial && !(key->flags & KEY_FLAG_INSTANTIATED))
+		goto invalid_key;
+
+	ret = -EACCES;
+	if (!key_permission(key, perm))
+		goto invalid_key;
+
+ error:
+	return key;
+
+ invalid_key:
+	key_put(key);
+	key = ERR_PTR(ret);
+	goto error;
+
+} /* end lookup_user_key() */
+
+/*****************************************************************************/
+/*
+ * join the named keyring as the session keyring if possible, or attempt to
+ * create a new one of that name if not
+ * - if the name is NULL, an empty anonymous keyring is installed instead
+ * - named session keyring joining is done with a semaphore held
+ */
+long join_session_keyring(const char *name)
+{
+	struct task_struct *tsk = current;
+	unsigned long flags;
+	struct key *keyring;
+	long ret;
+
+	/* if no name is provided, install an anonymous keyring */
+	if (!name) {
+		ret = install_session_keyring(tsk, NULL);
+		if (ret < 0)
+			goto error;
+
+		spin_lock_irqsave(&tsk->sighand->siglock, flags);
+		ret = tsk->signal->session_keyring->serial;
+		spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+		goto error;
+	}
+
+	/* allow the user to join or create a named keyring */
+	down(&key_session_sem);
+
+	/* look for an existing keyring of this name */
+	keyring = find_keyring_by_name(name, 0);
+	if (PTR_ERR(keyring) == -ENOKEY) {
+		/* not found - try and create a new one */
+		keyring = keyring_alloc(name, tsk->uid, tsk->gid, 0, NULL);
+		if (IS_ERR(keyring)) {
+			ret = PTR_ERR(keyring);
+			goto error;
+		}
+	}
+	else if (IS_ERR(keyring)) {
+		ret = PTR_ERR(keyring);
+		goto error2;
+	}
+
+	/* we've got a keyring - now to install it */
+	ret = install_session_keyring(tsk, keyring);
+	if (ret < 0)
+		goto error2;
+
+	ret = keyring->serial;
+	key_put(keyring);
+
+ error2:
+	up(&key_session_sem);
+ error:
+	return ret;
+
+} /* end join_session_keyring() */