* Peter Xu (pet...@redhat.com) wrote: > On Thu, Feb 17, 2022 at 06:04:07PM +0100, Hanna Reitz 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 <hre...@redhat.com> > > I had a similar fix here: > > https://lore.kernel.org/qemu-devel/20220216062809.57179-15-pet...@redhat.com/ > > Though there it was because I need migration_incoming_transport_cleanup() > for other purposes, so the fix came along. > > My guess is this small fix will land earlier, if so I'll rebase. :)
Actually it didn't; so since I've pulled a chunk of Peter's series in anyway I took the one from Peter's series. Dave > Thanks, > > -- > Peter Xu > > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
