// SPDX-License-Identifier: GPL-2.0-or-later /* Manage a process's keyrings * * Copyright (C) 2004-2005, 2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells ([email protected]) */ #include <linux/init.h> #include <linux/sched.h> #include <linux/sched/user.h> #include <linux/keyctl.h> #include <linux/fs.h> #include <linux/err.h> #include <linux/mutex.h> #include <linux/security.h> #include <linux/user_namespace.h> #include <linux/uaccess.h> #include <linux/init_task.h> #include <keys/request_key_auth-type.h> #include "internal.h" /* Session keyring create vs join semaphore */ static DEFINE_MUTEX(key_session_mutex); /* The root user's tracking struct */ struct key_user root_key_user = …; /* * Get or create a user register keyring. */ static struct key *get_user_register(struct user_namespace *user_ns) { … } /* * Look up the user and user session keyrings for the current process's UID, * creating them if they don't exist. */ int look_up_user_keyrings(struct key **_user_keyring, struct key **_user_session_keyring) { … } /* * Get the user session keyring if it exists, but don't create it if it * doesn't. */ struct key *get_user_session_keyring_rcu(const struct cred *cred) { … } /* * Install a thread keyring to the given credentials struct if it didn't have * one already. This is allowed to overrun the quota. * * Return: 0 if a thread keyring is now present; -errno on failure. */ int install_thread_keyring_to_cred(struct cred *new) { … } /* * Install a thread keyring to the current task if it didn't have one already. * * Return: 0 if a thread keyring is now present; -errno on failure. */ static int install_thread_keyring(void) { … } /* * Install a process keyring to the given credentials struct if it didn't have * one already. This is allowed to overrun the quota. * * Return: 0 if a process keyring is now present; -errno on failure. */ int install_process_keyring_to_cred(struct cred *new) { … } /* * Install a process keyring to the current task if it didn't have one already. * * Return: 0 if a process keyring is now present; -errno on failure. */ static int install_process_keyring(void) { … } /* * Install the given keyring as the session keyring of the given credentials * struct, replacing the existing one if any. If the given keyring is NULL, * then install a new anonymous session keyring. * @cred can not be in use by any task yet. * * Return: 0 on success; -errno on failure. */ int install_session_keyring_to_cred(struct cred *cred, struct key *keyring) { … } /* * Install the given keyring as the session keyring of the current task, * replacing the existing one if any. If the given keyring is NULL, then * install a new anonymous session keyring. * * Return: 0 on success; -errno on failure. */ static int install_session_keyring(struct key *keyring) { … } /* * Handle the fsuid changing. */ void key_fsuid_changed(struct cred *new_cred) { … } /* * Handle the fsgid changing. */ void key_fsgid_changed(struct cred *new_cred) { … } /* * Search the process keyrings attached to the supplied cred for the first * matching key under RCU conditions (the caller must be holding the RCU read * lock). * * The search criteria are the type and the match function. The description is * given to the match function as a parameter, but doesn't otherwise influence * the search. Typically the match function will compare the description * parameter to the key's description. * * This can only search keyrings that grant Search permission to the supplied * credentials. Keyrings linked to searched keyrings will also be searched if * they grant Search permission too. Keys can only be found if they grant * Search permission to the credentials. * * Returns a pointer to the key with the key usage count incremented if * successful, -EAGAIN if we didn't find any matching key or -ENOKEY if we only * matched negative keys. * * In the case of a successful return, the possession attribute is set on the * returned key reference. */ key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx) { … } /* * Search the process keyrings attached to the supplied cred for the first * matching key in the manner of search_my_process_keyrings(), but also search * the keys attached to the assumed authorisation key using its credentials if * one is available. * * The caller must be holding the RCU read lock. * * Return same as search_cred_keyrings_rcu(). */ key_ref_t search_process_keyrings_rcu(struct keyring_search_context *ctx) { … } /* * See if the key we're looking at is the target key. */ bool lookup_user_key_possessed(const struct key *key, const struct key_match_data *match_data) { … } /* * Look up a key ID given us by userspace with a given permissions mask to get * the key it refers to. * * Flags can be passed to request that special keyrings be created if referred * to directly, to permit partially constructed keys to be found and to skip * validity and permission checks on the found key. * * Returns a pointer to the key with an incremented usage count if successful; * -EINVAL if the key ID is invalid; -ENOKEY if the key ID does not correspond * to a key or the best found key was a negative key; -EKEYREVOKED or * -EKEYEXPIRED if the best found key was revoked or expired; -EACCES if the * found key doesn't grant the requested permit or the LSM denied access to it; * or -ENOMEM if a special keyring couldn't be created. * * In the case of a successful return, the possession attribute is set on the * returned key reference. */ key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags, enum key_need_perm need_perm) { … } EXPORT_SYMBOL(…); /* * Join the named keyring as the session keyring if possible else attempt to * create a new one of that name and join that. * * If the name is NULL, an empty anonymous keyring will be installed as the * session keyring. * * Named session keyrings are joined with a semaphore held to prevent the * keyrings from going away whilst the attempt is made to going them and also * to prevent a race in creating compatible session keyrings. */ long join_session_keyring(const char *name) { … } /* * Replace a process's session keyring on behalf of one of its children when * the target process is about to resume userspace execution. */ void key_change_session_keyring(struct callback_head *twork) { … } /* * Make sure that root's user and user-session keyrings exist. */ static int __init init_root_keyring(void) { … } late_initcall(init_root_keyring);
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