1 Chronicles 10:6 tells us this about the death of Saul:
On the other hand, 2 Samuel 2:8 tells us of a surviving son:
This certainly looks like a problem. The verse in 1 Chronicles seems to imply that Saul's whole family died in the battle, while 2 Samuel disagrees. However, there's another description of those events that is worth looking at, 1 Samuel 31:2:
By actually naming the sons of Saul that died, this passage does a lot to resolve the problem. It's clear that Ish-bosheth is not among the dead. Presumably, Saul had a son not present at the battle, and 1 Chronicles is only telling us about those who were there.
There's still the problem that "all [Saul's] house died together". This might seem to imply his entire family. If taken literally though, "his house" could simply mean those who actually lived with him.