Osmocom Libraries » libosmo-sccp + libosmo-sigtran

possibly related: https://gerrit.osmocom.org/c/libosmo-sccp/+/10443 (a patch that was merged after the one mentioned above was written)

So it's clear your patch is not correct with current code base. Mine I think was fixing the memleak fine but it was introducing a double-free on other code paths. I submitted a fix for that:
https://gerrit.osmocom.org/c/libosmo-sccp/+/16771 sua.c: Avoid double free in sua_rx_msg()->...->mtp_user_prim_cb()

Merged, closing.