Morning, My poor man's fuzzer found something interesting in SCTP. It seems like creating large number of SCTP sockets + some magic dance, upsets a memory subsystem related to SCTP. The sequence: - create SCTP socket - call setsockopts (SCTP_EVENTS) - call bind(::1, port) - call sendmsg(long buffer, MSG_CONFIRM, ::1, port) - close SCTP socket - repeat couple thousand times Full code: https://gist.github.com/majek/bd083dae769804d39134ce01f4f802bb#file-test_sctp-c I'm running it on virtme the simplest way: $ virtme-run --show-boot-console --rw --pwd --kimg bzImage --memory 512M --script-sh ./test_sctp Originally I was running it inside net namespace, and just having a localhost interface is sufficient to trigger the problem. Kernel is 5.2.1 (with KASAN and such, but that shouldn't be a factor). In some tests I saw a message that might indicate something funny hitting neighbor table: neighbour: ndisc_cache: neighbor table overflow! I'm not addr-decoding the stack trace, since it seems unrelated to the root cause. Cheers, Marek
