[RFC PATCH 15/27] keys: Make __key_link_begin() handle lockdep nesting

David Howells
2019-02-15T16:09:55Z

Make __key_link_begin() handle lockdep nesting for the implementation of
key_move() where we have to lock two keyrings.

Signed-off-by: David Howells <dhowells@redhat.com>
---

security/keys/internal.h | 2 +-
security/keys/key.c | 6 +++---
security/keys/keyring.c | 6 +++---
security/keys/request_key.c | 2 +-
4 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/security/keys/internal.h b/security/keys/internal.h
index 9f2a6ce67d15..40846657aebd 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -95,7 +95,7 @@ extern struct key_type *key_type_lookup(const char *type);
extern void key_type_put(struct key_type *ktype);
extern int key_get_type_from_user(char *, const char __user *, unsigned);

-extern int __key_link_begin(struct key *keyring,
+extern int __key_link_begin(struct key *keyring, unsigned int lock_nesting,
const struct keyring_index_key *index_key,
struct assoc_array_edit **_edit);
extern int __key_link_check_live_key(struct key *keyring, struct key *key);
diff --git a/security/keys/key.c b/security/keys/key.c
index 2c60d6bcf8a3..63513ffcf2e8 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -518,7 +518,7 @@ int key_instantiate_and_link(struct key *key,
}

if (keyring) {
- ret = __key_link_begin(keyring, &key->index_key, &edit);
+ ret = __key_link_begin(keyring, 0, &key->index_key, &edit);
if (ret < 0)
goto error;

@@ -586,7 +586,7 @@ int key_reject_and_link(struct key *key,
if (keyring->restrict_link)
return -EPERM;

- link_ret = __key_link_begin(keyring, &key->index_key, &edit);
+ link_ret = __key_link_begin(keyring, 0, &key->index_key, &edit);
}

mutex_lock(&key_construction_mutex);
@@ -866,7 +866,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
index_key.desc_len = strlen(index_key.description);
key_set_index_key(&index_key);

- ret = __key_link_begin(keyring, &index_key, &edit);
+ ret = __key_link_begin(keyring, 0, &index_key, &edit);
if (ret < 0) {
key_ref = ERR_PTR(ret);
goto error_free_prep;
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 431094c6cd74..1334ed97e530 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -1227,7 +1227,7 @@ static int keyring_detect_cycle(struct key *A, struct key *B)
/*
* Preallocate memory so that a key can be linked into to a keyring.
*/
-int __key_link_begin(struct key *keyring,
+int __key_link_begin(struct key *keyring, unsigned int lock_nesting,
const struct keyring_index_key *index_key,
struct assoc_array_edit **_edit)
__acquires(&keyring->sem)
@@ -1244,7 +1244,7 @@ int __key_link_begin(struct key *keyring,
if (keyring->type != &key_type_keyring)
return -ENOTDIR;

- down_write(&keyring->sem);
+ down_write_nested(&keyring->sem, lock_nesting);

ret = -EKEYREVOKED;
if (test_bit(KEY_FLAG_REVOKED, &keyring->flags))
@@ -1393,7 +1393,7 @@ int key_link(struct key *keyring, struct key *key)
key_check(keyring);
key_check(key);

- ret = __key_link_begin(keyring, &key->index_key, &edit);
+ ret = __key_link_begin(keyring, 0, &key->index_key, &edit);
if (ret == 0) {
kdebug("begun {%d,%d}", keyring->serial, refcount_read(&keyring->usage));
ret = __key_link_check_restriction(keyring, key);
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 078767564283..ab1f6de9e623 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -375,7 +375,7 @@ static int construct_alloc_key(struct keyring_search_context *ctx,
set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);

if (dest_keyring) {
- ret = __key_link_begin(dest_keyring, &ctx->index_key, &edit);
+ ret = __key_link_begin(dest_keyring, 0, &ctx->index_key, &edit);
if (ret < 0)
goto link_prealloc_failed;
}