libceph: align session_key and con_secret to 16 bytes
crypto_shash_setkey() and crypto_aead_setkey() will do a (small)
GFP_ATOMIC allocation to align the key if it isn't suitably aligned.
It's not a big deal, but at the same time easy to avoid.
The actual alignment requirement is dynamic, queryable with
crypto_shash_alignmask() and crypto_aead_alignmask(), but shouldn't
be stricter than 16 bytes for our algorithms.
Fixes: cd1a677cad99 ("libceph, ceph: implement msgr2.1 protocol (crc and secure modes)")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/net/ceph/messenger_v2.c b/net/ceph/messenger_v2.c
index 4f938fc..c38d8de 100644
--- a/net/ceph/messenger_v2.c
+++ b/net/ceph/messenger_v2.c
@@ -2033,10 +2033,18 @@ static int process_auth_reply_more(struct ceph_connection *con,
return -EINVAL;
}
+/*
+ * Align session_key and con_secret to avoid GFP_ATOMIC allocation
+ * inside crypto_shash_setkey() and crypto_aead_setkey() called from
+ * setup_crypto(). __aligned(16) isn't guaranteed to work for stack
+ * objects, so do it by hand.
+ */
static int process_auth_done(struct ceph_connection *con, void *p, void *end)
{
- u8 session_key[CEPH_KEY_LEN];
- u8 con_secret[CEPH_MAX_CON_SECRET_LEN];
+ u8 session_key_buf[CEPH_KEY_LEN + 16];
+ u8 con_secret_buf[CEPH_MAX_CON_SECRET_LEN + 16];
+ u8 *session_key = PTR_ALIGN(&session_key_buf[0], 16);
+ u8 *con_secret = PTR_ALIGN(&con_secret_buf[0], 16);
int session_key_len, con_secret_len;
int payload_len;
u64 global_id;
