time when the conntrack is created 2) attach new (different) helper B due to changes the reply tuple caused by NAT eg. port redirection from TCP/21 to TCP/5060 with both FTP and SIP helpers loaded, which seems to be a quite unorthodox scenario. I can provide a more elaborated patch to support this scenario but explicit helper attachment provides a better solution for this since now the use can attach the helpers consistently, without relying on the automatic helper lookup magic. This patch fixes a possible out of bound zeroing of the conntrack helper extension if the helper B uses more memory for its private data than helper A. Signed-off-by: Pablo Neira Ayuso %ǍnMx