ksmbd: validate compound response buffer

Add the check to validate compound response buffer.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 7b4689f..89c187a 100644 (file)
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -449,6 +449,12 @@ bool is_chained_smb2_message(struct ksmbd_work *work)
                        return false;
                }
 
+               if ((u64)get_rfc1002_len(work->response_buf) + MAX_CIFS_SMALL_BUFFER_SIZE >
+                   work->response_sz) {
+                       pr_err("next response offset exceeds response buffer size\n");
+                       return false;
+               }
+
                ksmbd_debug(SMB, "got SMB2 chained command\n");
                init_chained_smb2_rsp(work);
                return true;