ah. the problem is that struct isc_nmhandle grew a pointer member, adding 4 bytes to the struct size, and it uses C99 [] variable array for the final member, which is later assigned to other pointers, and this memory was now only 4-byte aligned. this hack patch works to stop named crashing for me, but i'll let christos figure out what the right general solution here is.
.mrg. Index: lib/isc/netmgr/netmgr-int.h =================================================================== RCS file: /cvsroot/src/external/mpl/bind/dist/lib/isc/netmgr/netmgr-int.h,v retrieving revision 1.8.2.1 diff -p -u -r1.8.2.1 netmgr-int.h --- lib/isc/netmgr/netmgr-int.h 25 Feb 2024 15:47:24 -0000 1.8.2.1 +++ lib/isc/netmgr/netmgr-int.h 5 Mar 2024 06:12:50 -0000 @@ -276,7 +276,7 @@ struct isc_nmhandle { LINK(isc_nmhandle_t) active_link; #endif void *opaque; - char extra[]; + char extra[] __attribute__((__aligned__(8))); }; typedef enum isc__netievent_type {