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KEYS: Deal with dead-type keys appropriately [try #6]

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Allow keys for which the key type has been removed to be unlinked.  Currently
dead-type keys can only be disposed of by completely clearing the keyrings
that point to them.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
This commit is contained in:
David Howells
2009-09-02 09:13:45 +01:00
committed by James Morris
parent e0e817392b
commit 5593122eec
4 changed files with 48 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
security/keys/internal.h
View File

@@ -124,8 +124,11 @@ extern struct key *request_key_and_link(struct key_type *type,
struct key *dest_keyring, struct key *dest_keyring,
unsigned long flags); unsigned long flags);
extern key_ref_t lookup_user_key(key_serial_t id, int create, int partial, extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
key_perm_t perm); key_perm_t perm);
#define KEY_LOOKUP_CREATE 0x01
#define KEY_LOOKUP_PARTIAL 0x02
#define KEY_LOOKUP_FOR_UNLINK 0x04
extern long join_session_keyring(const char *name); extern long join_session_keyring(const char *name);

6
security/keys/key.c
View File

@@ -642,10 +642,8 @@ struct key *key_lookup(key_serial_t id)
goto error; goto error;
found: found:
/* pretend it doesn't exist if it's dead */ /* pretend it doesn't exist if it is awaiting deletion */
if (atomic_read(&key->usage) == 0 || if (atomic_read(&key->usage) == 0)
test_bit(KEY_FLAG_DEAD, &key->flags) ||
key->type == &key_type_dead)
goto not_found; goto not_found;
/* this races with key_put(), but that doesn't matter since key_put() /* this races with key_put(), but that doesn't matter since key_put()

50
security/keys/keyctl.c
View File

@@ -103,7 +103,7 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type,
} }
/* find the target keyring (which must be writable) */ /* find the target keyring (which must be writable) */
keyring_ref = lookup_user_key(ringid, 1, 0, KEY_WRITE); keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
if (IS_ERR(keyring_ref)) { if (IS_ERR(keyring_ref)) {
ret = PTR_ERR(keyring_ref); ret = PTR_ERR(keyring_ref);
goto error3; goto error3;
@@ -185,7 +185,8 @@ SYSCALL_DEFINE4(request_key, const char __user *, _type,
/* get the destination keyring if specified */ /* get the destination keyring if specified */
dest_ref = NULL; dest_ref = NULL;
if (destringid) { if (destringid) {
dest_ref = lookup_user_key(destringid, 1, 0, KEY_WRITE); dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
KEY_WRITE);
if (IS_ERR(dest_ref)) { if (IS_ERR(dest_ref)) {
ret = PTR_ERR(dest_ref); ret = PTR_ERR(dest_ref);
goto error3; goto error3;
@@ -233,9 +234,11 @@ SYSCALL_DEFINE4(request_key, const char __user *, _type,
long keyctl_get_keyring_ID(key_serial_t id, int create) long keyctl_get_keyring_ID(key_serial_t id, int create)
{ {
key_ref_t key_ref; key_ref_t key_ref;
unsigned long lflags;
long ret; long ret;
key_ref = lookup_user_key(id, create, 0, KEY_SEARCH); lflags = create ? KEY_LOOKUP_CREATE : 0;
key_ref = lookup_user_key(id, lflags, KEY_SEARCH);
if (IS_ERR(key_ref)) { if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref); ret = PTR_ERR(key_ref);
goto error; goto error;
@@ -309,7 +312,7 @@ long keyctl_update_key(key_serial_t id,
} }
/* find the target key (which must be writable) */ /* find the target key (which must be writable) */
key_ref = lookup_user_key(id, 0, 0, KEY_WRITE); key_ref = lookup_user_key(id, 0, KEY_WRITE);
if (IS_ERR(key_ref)) { if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref); ret = PTR_ERR(key_ref);
goto error2; goto error2;
@@ -337,7 +340,7 @@ long keyctl_revoke_key(key_serial_t id)
key_ref_t key_ref; key_ref_t key_ref;
long ret; long ret;
key_ref = lookup_user_key(id, 0, 0, KEY_WRITE); key_ref = lookup_user_key(id, 0, KEY_WRITE);
if (IS_ERR(key_ref)) { if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref); ret = PTR_ERR(key_ref);
goto error; goto error;
@@ -363,7 +366,7 @@ long keyctl_keyring_clear(key_serial_t ringid)
key_ref_t keyring_ref; key_ref_t keyring_ref;
long ret; long ret;
keyring_ref = lookup_user_key(ringid, 1, 0, KEY_WRITE); keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
if (IS_ERR(keyring_ref)) { if (IS_ERR(keyring_ref)) {
ret = PTR_ERR(keyring_ref); ret = PTR_ERR(keyring_ref);
goto error; goto error;
@@ -389,13 +392,13 @@ long keyctl_keyring_link(key_serial_t id, key_serial_t ringid)
key_ref_t keyring_ref, key_ref; key_ref_t keyring_ref, key_ref;
long ret; long ret;
keyring_ref = lookup_user_key(ringid, 1, 0, KEY_WRITE); keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
if (IS_ERR(keyring_ref)) { if (IS_ERR(keyring_ref)) {
ret = PTR_ERR(keyring_ref); ret = PTR_ERR(keyring_ref);
goto error; goto error;
} }
key_ref = lookup_user_key(id, 1, 0, KEY_LINK); key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_LINK);
if (IS_ERR(key_ref)) { if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref); ret = PTR_ERR(key_ref);
goto error2; goto error2;
@@ -423,13 +426,13 @@ long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
key_ref_t keyring_ref, key_ref; key_ref_t keyring_ref, key_ref;
long ret; long ret;
keyring_ref = lookup_user_key(ringid, 0, 0, KEY_WRITE); keyring_ref = lookup_user_key(ringid, 0, KEY_WRITE);
if (IS_ERR(keyring_ref)) { if (IS_ERR(keyring_ref)) {
ret = PTR_ERR(keyring_ref); ret = PTR_ERR(keyring_ref);
goto error; goto error;
} }
key_ref = lookup_user_key(id, 0, 0, 0); key_ref = lookup_user_key(id, KEY_LOOKUP_FOR_UNLINK, 0);
if (IS_ERR(key_ref)) { if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref); ret = PTR_ERR(key_ref);
goto error2; goto error2;
@@ -465,7 +468,7 @@ long keyctl_describe_key(key_serial_t keyid,
char *tmpbuf; char *tmpbuf;
long ret; long ret;
key_ref = lookup_user_key(keyid, 0, 1, KEY_VIEW); key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
if (IS_ERR(key_ref)) { if (IS_ERR(key_ref)) {
/* viewing a key under construction is permitted if we have the /* viewing a key under construction is permitted if we have the
* authorisation token handy */ * authorisation token handy */
@@ -474,7 +477,8 @@ long keyctl_describe_key(key_serial_t keyid,
if (!IS_ERR(instkey)) { if (!IS_ERR(instkey)) {
key_put(instkey); key_put(instkey);
key_ref = lookup_user_key(keyid, key_ref = lookup_user_key(keyid,
0, 1, 0); KEY_LOOKUP_PARTIAL,
0);
if (!IS_ERR(key_ref)) if (!IS_ERR(key_ref))
goto okay; goto okay;
} }
@@ -558,7 +562,7 @@ long keyctl_keyring_search(key_serial_t ringid,
} }
/* get the keyring at which to begin the search */ /* get the keyring at which to begin the search */
keyring_ref = lookup_user_key(ringid, 0, 0, KEY_SEARCH); keyring_ref = lookup_user_key(ringid, 0, KEY_SEARCH);
if (IS_ERR(keyring_ref)) { if (IS_ERR(keyring_ref)) {
ret = PTR_ERR(keyring_ref); ret = PTR_ERR(keyring_ref);
goto error2; goto error2;
@@ -567,7 +571,8 @@ long keyctl_keyring_search(key_serial_t ringid,
/* get the destination keyring if specified */ /* get the destination keyring if specified */
dest_ref = NULL; dest_ref = NULL;
if (destringid) { if (destringid) {
dest_ref = lookup_user_key(destringid, 1, 0, KEY_WRITE); dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
KEY_WRITE);
if (IS_ERR(dest_ref)) { if (IS_ERR(dest_ref)) {
ret = PTR_ERR(dest_ref); ret = PTR_ERR(dest_ref);
goto error3; goto error3;
@@ -637,7 +642,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
long ret; long ret;
/* find the key first */ /* find the key first */
key_ref = lookup_user_key(keyid, 0, 0, 0); key_ref = lookup_user_key(keyid, 0, 0);
if (IS_ERR(key_ref)) { if (IS_ERR(key_ref)) {
ret = -ENOKEY; ret = -ENOKEY;
goto error; goto error;
@@ -700,7 +705,8 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid)
if (uid == (uid_t) -1 && gid == (gid_t) -1) if (uid == (uid_t) -1 && gid == (gid_t) -1)
goto error; goto error;
key_ref = lookup_user_key(id, 1, 1, KEY_SETATTR); key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
KEY_SETATTR);
if (IS_ERR(key_ref)) { if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref); ret = PTR_ERR(key_ref);
goto error; goto error;
@@ -805,7 +811,8 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm)
if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL)) if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL))
goto error; goto error;
key_ref = lookup_user_key(id, 1, 1, KEY_SETATTR); key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
KEY_SETATTR);
if (IS_ERR(key_ref)) { if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref); ret = PTR_ERR(key_ref);
goto error; goto error;
@@ -847,7 +854,7 @@ static long get_instantiation_keyring(key_serial_t ringid,
/* if a specific keyring is nominated by ID, then use that */ /* if a specific keyring is nominated by ID, then use that */
if (ringid > 0) { if (ringid > 0) {
dkref = lookup_user_key(ringid, 1, 0, KEY_WRITE); dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
if (IS_ERR(dkref)) if (IS_ERR(dkref))
return PTR_ERR(dkref); return PTR_ERR(dkref);
*_dest_keyring = key_ref_to_ptr(dkref); *_dest_keyring = key_ref_to_ptr(dkref);
@@ -1083,7 +1090,8 @@ long keyctl_set_timeout(key_serial_t id, unsigned timeout)
time_t expiry; time_t expiry;
long ret; long ret;
key_ref = lookup_user_key(id, 1, 1, KEY_SETATTR); key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
KEY_SETATTR);
if (IS_ERR(key_ref)) { if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref); ret = PTR_ERR(key_ref);
goto error; goto error;
@@ -1170,7 +1178,7 @@ long keyctl_get_security(key_serial_t keyid,
char *context; char *context;
long ret; long ret;
key_ref = lookup_user_key(keyid, 0, 1, KEY_VIEW); key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
if (IS_ERR(key_ref)) { if (IS_ERR(key_ref)) {
if (PTR_ERR(key_ref) != -EACCES) if (PTR_ERR(key_ref) != -EACCES)
return PTR_ERR(key_ref); return PTR_ERR(key_ref);
@@ -1182,7 +1190,7 @@ long keyctl_get_security(key_serial_t keyid,
return PTR_ERR(key_ref); return PTR_ERR(key_ref);
key_put(instkey); key_put(instkey);
key_ref = lookup_user_key(keyid, 0, 1, 0); key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, 0);
if (IS_ERR(key_ref)) if (IS_ERR(key_ref))
return PTR_ERR(key_ref); return PTR_ERR(key_ref);
} }

18
security/keys/process_keys.c
View File

@@ -487,7 +487,7 @@ static int lookup_user_key_possessed(const struct key *key, const void *target)
* - don't create special keyrings unless so requested * - don't create special keyrings unless so requested
* - partially constructed keys aren't found unless requested * - partially constructed keys aren't found unless requested
*/ */
key_ref_t lookup_user_key(key_serial_t id, int create, int partial, key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags,
key_perm_t perm) key_perm_t perm)
{ {
struct request_key_auth *rka; struct request_key_auth *rka;
@@ -503,7 +503,7 @@ try_again:
switch (id) { switch (id) {
case KEY_SPEC_THREAD_KEYRING: case KEY_SPEC_THREAD_KEYRING:
if (!cred->thread_keyring) { if (!cred->thread_keyring) {
if (!create) if (!(lflags & KEY_LOOKUP_CREATE))
goto error; goto error;
ret = install_thread_keyring(); ret = install_thread_keyring();
@@ -521,7 +521,7 @@ try_again:
case KEY_SPEC_PROCESS_KEYRING: case KEY_SPEC_PROCESS_KEYRING:
if (!cred->tgcred->process_keyring) { if (!cred->tgcred->process_keyring) {
if (!create) if (!(lflags & KEY_LOOKUP_CREATE))
goto error; goto error;
ret = install_process_keyring(); ret = install_process_keyring();
@@ -642,7 +642,14 @@ try_again:
break; break;
} }
if (!partial) { /* unlink does not use the nominated key in any way, so can skip all
* the permission checks as it is only concerned with the keyring */
if (lflags & KEY_LOOKUP_FOR_UNLINK) {
ret = 0;
goto error;
}
if (!(lflags & KEY_LOOKUP_PARTIAL)) {
ret = wait_for_key_construction(key, true); ret = wait_for_key_construction(key, true);
switch (ret) { switch (ret) {
case -ERESTARTSYS: case -ERESTARTSYS:
@@ -660,7 +667,8 @@ try_again:
} }
ret = -EIO; ret = -EIO;
if (!partial && !test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) if (!(lflags & KEY_LOOKUP_PARTIAL) &&
!test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
goto invalid_key; goto invalid_key;
/* check the permissions */ /* check the permissions */