ksmbd: fix slub overflow in ksmbd_decode_ntlmssp_auth_blob()

If authblob->SessionKey.Length is bigger than session key size(CIFS_KEY_SIZE), slub overflow can happen in key exchange codes. cifs_arc4_crypt copy to session key array from SessionKey from client. Reported-by: [email protected] # ZDI-CAN-21940 Signed-off-by: Namjae Jeon <[email protected]>
namjaejeon · Aug 25, 2023 · 04216d3 · 04216d3
1 parent 34af6fa
commit 04216d3
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/auth.c b/auth.c
@@ -636,6 +636,9 @@ int ksmbd_decode_ntlmssp_auth_blob(struct authenticate_message *authblob,
 		if (blob_len < (u64)sess_key_off + sess_key_len)
 			return -EINVAL;
 
+		if (sess_key_len > CIFS_KEY_SIZE)
+			return -EINVAL;
+
 		ctx_arc4 = kmalloc(sizeof(*ctx_arc4), GFP_KERNEL);
 		if (!ctx_arc4)
 			return -ENOMEM;