On Tue, Jul 16, 2019 at 11:47:40PM +0200, Marek Majkowski wrote: > 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. > Why would you have to decode anything, the decoded stack trace should be available in your demsg log. Cant you just attach that here? Neil > Cheers, > Marek >
