[PATCH] ksmbd: Don't log keys in SMB3 signing and encryption key generation

From: Thorsten Blum

Date: Tue Mar 03 2026 - 08:27:22 EST


When KSMBD_DEBUG_AUTH logging is enabled, generate_smb3signingkey() and
generate_smb3encryptionkey() log the session, signing, encryption, and
decryption key bytes. Remove the logs to avoid exposing credentials.

Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Thorsten Blum <thorsten.blum@xxxxxxxxx>
---
fs/smb/server/auth.c | 22 ++--------------------
1 file changed, 2 insertions(+), 20 deletions(-)

diff --git a/fs/smb/server/auth.c b/fs/smb/server/auth.c
index 5fe8c667c6b1..af5f40304331 100644
--- a/fs/smb/server/auth.c
+++ b/fs/smb/server/auth.c
@@ -589,12 +589,8 @@ static int generate_smb3signingkey(struct ksmbd_session *sess,
if (!(conn->dialect >= SMB30_PROT_ID && signing->binding))
memcpy(chann->smb3signingkey, key, SMB3_SIGN_KEY_SIZE);

- ksmbd_debug(AUTH, "dumping generated AES signing keys\n");
+ ksmbd_debug(AUTH, "generated SMB3 signing key\n");
ksmbd_debug(AUTH, "Session Id %llu\n", sess->id);
- ksmbd_debug(AUTH, "Session Key %*ph\n",
- SMB2_NTLMV2_SESSKEY_SIZE, sess->sess_key);
- ksmbd_debug(AUTH, "Signing Key %*ph\n",
- SMB3_SIGN_KEY_SIZE, key);
return 0;
}

@@ -652,23 +648,9 @@ static void generate_smb3encryptionkey(struct ksmbd_conn *conn,
ptwin->decryption.context,
sess->smb3decryptionkey, SMB3_ENC_DEC_KEY_SIZE);

- ksmbd_debug(AUTH, "dumping generated AES encryption keys\n");
+ ksmbd_debug(AUTH, "generated SMB3 encryption/decryption keys\n");
ksmbd_debug(AUTH, "Cipher type %d\n", conn->cipher_type);
ksmbd_debug(AUTH, "Session Id %llu\n", sess->id);
- ksmbd_debug(AUTH, "Session Key %*ph\n",
- SMB2_NTLMV2_SESSKEY_SIZE, sess->sess_key);
- if (conn->cipher_type == SMB2_ENCRYPTION_AES256_CCM ||
- conn->cipher_type == SMB2_ENCRYPTION_AES256_GCM) {
- ksmbd_debug(AUTH, "ServerIn Key %*ph\n",
- SMB3_GCM256_CRYPTKEY_SIZE, sess->smb3encryptionkey);
- ksmbd_debug(AUTH, "ServerOut Key %*ph\n",
- SMB3_GCM256_CRYPTKEY_SIZE, sess->smb3decryptionkey);
- } else {
- ksmbd_debug(AUTH, "ServerIn Key %*ph\n",
- SMB3_GCM128_CRYPTKEY_SIZE, sess->smb3encryptionkey);
- ksmbd_debug(AUTH, "ServerOut Key %*ph\n",
- SMB3_GCM128_CRYPTKEY_SIZE, sess->smb3decryptionkey);
- }
}

void ksmbd_gen_smb30_encryptionkey(struct ksmbd_conn *conn,
--
Thorsten Blum <thorsten.blum@xxxxxxxxx>
GPG: 1D60 735E 8AEF 3BE4 73B6 9D84 7336 78FD 8DFE EAD4