* Hanna Reitz ([email protected]) wrote: > migration_incoming_state_destroy() NULLs all objects it frees after they > are freed, presumably so that a subsequent call to the same function > will not free them again, unless new objects have been created in the > meantime. > > transport_data is the exception, and it shows exactly this problem: When > an incoming migration uses transport_cleanup() and transport_data, and a > subsequent incoming migration (e.g. loadvm) occurs that does not, then > when this second one is done, it will call transport_cleanup() on the > old transport_data again -- which has already been freed. This is > sometimes visible in the iotest 201, though for some reason I can only > reproduce it with -m32. > > To fix this, call transport_cleanup() only when transport_data is not > NULL (otherwise there is nothing to clean up), and set transport_data to > NULL when it has been cleaned up (i.e. freed). > > (transport_cleanup() is used only by migration/socket.c, where > socket_start_incoming_migration_internal() sets both it and > transport_data to non-NULL values.) > > Signed-off-by: Hanna Reitz <[email protected]>
That probably deserves a fixes: a59136f Reviewed-by: Dr. David Alan Gilbert <[email protected]> > --- > migration/migration.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/migration/migration.c b/migration/migration.c > index bcc385b94b..cdb2e76d02 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -287,8 +287,9 @@ void migration_incoming_state_destroy(void) > g_array_free(mis->postcopy_remote_fds, TRUE); > mis->postcopy_remote_fds = NULL; > } > - if (mis->transport_cleanup) { > + if (mis->transport_cleanup && mis->transport_data) { > mis->transport_cleanup(mis->transport_data); > + mis->transport_data = NULL; > } > > qemu_event_reset(&mis->main_thread_load_event); > -- > 2.34.1 > -- Dr. David Alan Gilbert / [email protected] / Manchester, UK
