[PATCH] libceph: Remove obsolete session key alignment logic

[PATCH] libceph: Remove obsolete session key alignment logic

[Eric Biggers]

Since the call to crypto_shash_setkey() was replaced with
hmac_sha256_preparekey() which doesn't allocate memory regardless of the
alignment of the input key, remove the session key alignment logic from
process_auth_done().  Also remove the inclusion of crypto/hash.h, which
is no longer needed since crypto_shash is no longer used.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
 net/ceph/messenger_v2.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/net/ceph/messenger_v2.c b/net/ceph/messenger_v2.c
index 50f65820f623f..865a9221315b0 100644
--- a/net/ceph/messenger_v2.c
+++ b/net/ceph/messenger_v2.c
@@ -6,11 +6,10 @@
  */
 
 #include <linux/ceph/ceph_debug.h>
 
 #include <crypto/aead.h>
-#include <crypto/hash.h>
 #include <crypto/sha2.h>
 #include <crypto/utils.h>
 #include <linux/bvec.h>
 #include <linux/crc32c.h>
 #include <linux/net.h>
@@ -2350,20 +2349,18 @@ static int process_auth_reply_more(struct ceph_connection *con,
 	pr_err("failed to decode auth_reply_more\n");
 	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
+ * Align con_secret to avoid GFP_ATOMIC allocation inside 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_buf[CEPH_MAX_KEY_LEN + 16];
+	u8 session_key[CEPH_MAX_KEY_LEN];
 	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;
 	int ret;
@@ -2413,11 +2410,11 @@ static int process_auth_done(struct ceph_connection *con, void *p, void *end)
 	}
 
 	con->state = CEPH_CON_S_V2_AUTH_SIGNATURE;
 
 out:
-	memzero_explicit(session_key_buf, sizeof(session_key_buf));
+	memzero_explicit(session_key, sizeof(session_key));
 	memzero_explicit(con_secret_buf, sizeof(con_secret_buf));
 	return ret;
 
 bad:
 	pr_err("failed to decode auth_done\n");

base-commit: 1c9982b4961334c1edb0745a04cabd34bc2de675
-- 
2.53.0

Re: [PATCH] libceph: Remove obsolete session key alignment logic

[Ilya Dryomov]

On Sat, Mar 14, 2026 at 10:26 PM Eric Biggers <ebiggers@kernel.org> wrote:
>
> Since the call to crypto_shash_setkey() was replaced with
> hmac_sha256_preparekey() which doesn't allocate memory regardless of the
> alignment of the input key, remove the session key alignment logic from
> process_auth_done().  Also remove the inclusion of crypto/hash.h, which
> is no longer needed since crypto_shash is no longer used.
>
> Signed-off-by: Eric Biggers <ebiggers@kernel.org>
> ---
>  net/ceph/messenger_v2.c | 11 ++++-------
>  1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/net/ceph/messenger_v2.c b/net/ceph/messenger_v2.c
> index 50f65820f623f..865a9221315b0 100644
> --- a/net/ceph/messenger_v2.c
> +++ b/net/ceph/messenger_v2.c
> @@ -6,11 +6,10 @@
>   */
>
>  #include <linux/ceph/ceph_debug.h>
>
>  #include <crypto/aead.h>
> -#include <crypto/hash.h>
>  #include <crypto/sha2.h>
>  #include <crypto/utils.h>
>  #include <linux/bvec.h>
>  #include <linux/crc32c.h>
>  #include <linux/net.h>
> @@ -2350,20 +2349,18 @@ static int process_auth_reply_more(struct ceph_connection *con,
>         pr_err("failed to decode auth_reply_more\n");
>         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
> + * Align con_secret to avoid GFP_ATOMIC allocation inside 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_buf[CEPH_MAX_KEY_LEN + 16];
> +       u8 session_key[CEPH_MAX_KEY_LEN];
>         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;
>         int ret;
> @@ -2413,11 +2410,11 @@ static int process_auth_done(struct ceph_connection *con, void *p, void *end)
>         }
>
>         con->state = CEPH_CON_S_V2_AUTH_SIGNATURE;
>
>  out:
> -       memzero_explicit(session_key_buf, sizeof(session_key_buf));
> +       memzero_explicit(session_key, sizeof(session_key));
>         memzero_explicit(con_secret_buf, sizeof(con_secret_buf));
>         return ret;
>
>  bad:
>         pr_err("failed to decode auth_done\n");
>
> base-commit: 1c9982b4961334c1edb0745a04cabd34bc2de675
> --
> 2.53.0
>

Applied.

Thanks,

                Ilya