3.2.67-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Sasha Levin <sasha.le...@oracle.com> commit a3a8784454692dd72e5d5d34dcdab17b4420e74c upstream. When a key is being garbage collected, it's key->user would get put before the ->destroy() callback is called, where the key is removed from it's respective tracking structures. This leaves a key hanging in a semi-invalid state which leaves a window open for a different task to try an access key->user. An example is find_keyring_by_name() which would dereference key->user for a key that is in the process of being garbage collected (where key->user was freed but ->destroy() wasn't called yet - so it's still present in the linked list). This would cause either a panic, or corrupt memory. Fixes CVE-2014-9529. Signed-off-by: Sasha Levin <sasha.le...@oracle.com> Signed-off-by: David Howells <dhowe...@redhat.com> [bwh: Backported to 3.2: adjust indentation] Signed-off-by: Ben Hutchings <b...@decadent.org.uk> --- security/keys/gc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/security/keys/gc.c +++ b/security/keys/gc.c @@ -186,12 +186,12 @@ static noinline void key_gc_unused_key(s if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) atomic_dec(&key->user->nikeys); - key_user_put(key->user); - /* now throw away the key memory */ if (key->type->destroy) key->type->destroy(key); + key_user_put(key->user); + kfree(key->description); #ifdef KEY_DEBUGGING -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/