From f5f2c9a0e3073debc6bc0ecc855ced0158526ee8 Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Tue, 15 Dec 2020 16:49:07 +0100 Subject: [PATCH] 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 --- net/ceph/messenger_v2.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/net/ceph/messenger_v2.c b/net/ceph/messenger_v2.c index 4f938fc8deaf..c38d8de93836 100644 --- a/net/ceph/messenger_v2.c +++ b/net/ceph/messenger_v2.c @@ -2033,10 +2033,18 @@ bad: 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; -- 2.20.1