[PATCH 3.16.y-ckt 069/118] KEYS: ensure we free the assoc array edit if edit is valid

From: Luis Henriques
Date: Wed Aug 12 2015 - 05:23:05 EST

3.16.7-ckt16 -stable review patch. If anyone has any objections, please let me know.


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

commit ca4da5dd1f99fe9c59f1709fb43e818b18ad20e0 upstream.

__key_link_end is not freeing the associated array edit structure
and this leads to a 512 byte memory leak each time an identical
existing key is added with add_key().

The reason the add_key() system call returns okay is that
key_create_or_update() calls __key_link_begin() before checking to see
whether it can update a key directly rather than adding/replacing - which
it turns out it can. Thus __key_link() is not called through
__key_instantiate_and_link() and __key_link_end() must cancel the edit.


Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: James Morris <james.l.morris@xxxxxxxxxx>
Cc: Moritz MÃhlenhoff <jmm@xxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
security/keys/keyring.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 9cf2575f0d97..860345cb05f1 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -1151,9 +1151,11 @@ void __key_link_end(struct key *keyring,
if (index_key->type == &key_type_keyring)

- if (edit && !edit->dead_leaf) {
- key_payload_reserve(keyring,
- keyring->datalen - KEYQUOTA_LINK_BYTES);
+ if (edit) {
+ if (!edit->dead_leaf) {
+ key_payload_reserve(keyring,
+ keyring->datalen - KEYQUOTA_LINK_BYTES);
+ }
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