[PATCH] keys: ensure that ->match_free() is called in request_key_and_link()

From: David Howells
Date: Fri Aug 30 2019 - 11:52:30 EST


From: Eric Biggers <ebiggers@xxxxxxxxxx>

If check_cached_key() returns a non-NULL value, we still need to call
key_type::match_free() to undo key_type::match_preparse().

Fixes: 7743c48e54ee ("keys: Cache result of request_key*() temporarily in task_struct")
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

security/keys/request_key.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 7325f382dbf4..957b9e3e1492 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -595,7 +595,7 @@ struct key *request_key_and_link(struct key_type *type,

key = check_cached_key(&ctx);
if (key)
- return key;
+ goto error_free;

/* search all the process keyrings for a key */
rcu_read_lock();