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

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

[Thorsten Blum]

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@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 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@linux.dev>
GPG: 1D60 735E 8AEF 3BE4 73B6  9D84 7336 78FD 8DFE EAD4

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

[Namjae Jeon]

On Tue, Mar 3, 2026 at 10:27 PM Thorsten Blum <thorsten.blum@linux.dev> wrote:
>
> 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@vger.kernel.org
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Applied it to #ksmbd-for-next-next.
Thanks!