Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 31204ed9 authored by David Howells's avatar David Howells Committed by Linus Torvalds
Browse files

[PATCH] keys: discard the contents of a key on revocation 



Cause the keys linked to a keyring to be unlinked from it when revoked and it
causes the data attached to a user-defined key to be discarded when revoked.

This frees up most of the quota a key occupied at that point, rather than
waiting for the key to actually be destroyed.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 7e047ef5

include/keys/user-type.h

+1 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ extern struct key_type key_type_user; 
extern int user_instantiate(struct key *key, const void *data, size_t datalen);

extern int user_update(struct key *key, const void *data, size_t datalen);

extern int user_match(const struct key *key, const void *criterion);

extern void user_revoke(struct key *key);

extern void user_destroy(struct key *key);

extern void user_describe(const struct key *user, struct seq_file *m);

extern long user_read(const struct key *key,

security/keys/keyring.c

+21 −0
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ static inline unsigned keyring_hash(const char *desc) 
static int keyring_instantiate(struct key *keyring,

			       const void *data, size_t datalen);

static int keyring_match(const struct key *keyring, const void *criterion);

static void keyring_revoke(struct key *keyring);

static void keyring_destroy(struct key *keyring);

static void keyring_describe(const struct key *keyring, struct seq_file *m);

static long keyring_read(const struct key *keyring,
@@ -59,6 +60,7 @@ struct key_type key_type_keyring = { 
	.def_datalen	= sizeof(struct keyring_list),

	.instantiate	= keyring_instantiate,

	.match		= keyring_match,

	.revoke		= keyring_revoke,

	.destroy	= keyring_destroy,

	.describe	= keyring_describe,

	.read		= keyring_read,
@@ -953,3 +955,22 @@ int keyring_clear(struct key *keyring) 
} /* end keyring_clear() */



EXPORT_SYMBOL(keyring_clear);



/*****************************************************************************/

/*

 * dispose of the links from a revoked keyring

 * - called with the key sem write-locked

 */

static void keyring_revoke(struct key *keyring)

{

	struct keyring_list *klist = keyring->payload.subscriptions;



	/* adjust the quota */

	key_payload_reserve(keyring, 0);



	if (klist) {

		rcu_assign_pointer(keyring->payload.subscriptions, NULL);

		call_rcu(&klist->rcu, keyring_clear_rcu_disposal);

	}



} /* end keyring_revoke() */

security/keys/user_defined.c

+24 −1
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ struct key_type key_type_user = { 
	.instantiate	= user_instantiate,

	.update		= user_update,

	.match		= user_match,

	.revoke		= user_revoke,

	.destroy	= user_destroy,

	.describe	= user_describe,

	.read		= user_read,
@@ -67,6 +68,7 @@ int user_instantiate(struct key *key, const void *data, size_t datalen) 
	return ret;



} /* end user_instantiate() */



EXPORT_SYMBOL_GPL(user_instantiate);



/*****************************************************************************/
@@ -141,7 +143,28 @@ EXPORT_SYMBOL_GPL(user_match); 


/*****************************************************************************/

/*

 * dispose of the data dangling from the corpse of a user

 * dispose of the links from a revoked keyring

 * - called with the key sem write-locked

 */

void user_revoke(struct key *key)

{

	struct user_key_payload *upayload = key->payload.data;



	/* clear the quota */

	key_payload_reserve(key, 0);



	if (upayload) {

		rcu_assign_pointer(key->payload.data, NULL);

		call_rcu(&upayload->rcu, user_update_rcu_disposal);

	}



} /* end user_revoke() */



EXPORT_SYMBOL(user_revoke);



/*****************************************************************************/

/*

 * dispose of the data dangling from the corpse of a user key

 */

void user_destroy(struct key *key)

{