smb: client: Add check for next_buffer in receive_encrypted_standard()

Add check for the return value of cifs_buf_get() and cifs_small_buf_get()
in receive_encrypted_standard() to prevent null pointer dereference.

Fixes: eec04ea11969 ("smb: client: fix OOB in receive_encrypted_standard()")
Cc: [e-mail]
Signed-off-by: Haoxiang Li <[e-mail]>
Signed-off-by: Steve French <[e-mail]>

fs/smb/client/smb2ops.c

···
 			next_buffer = (char *)cifs_buf_get();
 		else
 			next_buffer = (char *)cifs_small_buf_get();
+		if (!next_buffer) {
+			cifs_server_dbg(VFS, "No memory for (large) SMB response\n");
+			return -1;
+		}
 		memcpy(next_buffer, buf + next_cmd, pdu_length - next_cmd);
 	}