Re: [PATCH 2/2] migration/multifd: Do error_free after migrate_set_error to avoid memleaks

[Juan Quintela <quintela@redhat.com>]

Pan Nengyuan <pannengyuan@huawei.com> wrote:
> When error happen in multifd_send_thread, it use error_copy to set migrate error in
> multifd_send_terminate_threads(). We should call error_free after it.
>
> Similarly, fix another two places in multifd_recv_thread/multifd_save_cleanup.
>
> The leak stack:
> Direct leak of 48 byte(s) in 1 object(s) allocated from:
>     #0 0x7f781af07cf0 in calloc (/lib64/libasan.so.5+0xefcf0)
>     #1 0x7f781a2ce22d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5322d)
>     #2 0x55ee1d075c17 in error_setv /mnt/sdb/backup/qemu/util/error.c:61
>     #3 0x55ee1d076464 in error_setg_errno_internal /mnt/sdb/backup/qemu/util/error.c:109
>     #4 0x55ee1cef066e in qio_channel_socket_writev /mnt/sdb/backup/qemu/io/channel-socket.c:569
>     #5 0x55ee1cee806b in qio_channel_writev /mnt/sdb/backup/qemu/io/channel.c:207
>     #6 0x55ee1cee806b in qio_channel_writev_all /mnt/sdb/backup/qemu/io/channel.c:171
>     #7 0x55ee1cee8248 in qio_channel_write_all /mnt/sdb/backup/qemu/io/channel.c:257
>     #8 0x55ee1ca12c9a in multifd_send_thread /mnt/sdb/backup/qemu/migration/multifd.c:657
>     #9 0x55ee1d0607fc in qemu_thread_start /mnt/sdb/backup/qemu/util/qemu-thread-posix.c:519
>     #10 0x7f78159ae2dd in start_thread (/lib64/libpthread.so.0+0x82dd)
>     #11 0x7f78156df4b2 in __GI___clone (/lib64/libc.so.6+0xfc4b2)
>
> Indirect leak of 52 byte(s) in 1 object(s) allocated from:
>     #0 0x7f781af07f28 in __interceptor_realloc (/lib64/libasan.so.5+0xeff28)
>     #1 0x7f78156f07d9 in __GI___vasprintf_chk (/lib64/libc.so.6+0x10d7d9)
>     #2 0x7f781a30ea6c in g_vasprintf (/lib64/libglib-2.0.so.0+0x93a6c)
>     #3 0x7f781a2e7cd0 in g_strdup_vprintf (/lib64/libglib-2.0.so.0+0x6ccd0)
>     #4 0x7f781a2e7d8c in g_strdup_printf (/lib64/libglib-2.0.so.0+0x6cd8c)
>     #5 0x55ee1d075c86 in error_setv /mnt/sdb/backup/qemu/util/error.c:65
>     #6 0x55ee1d076464 in error_setg_errno_internal /mnt/sdb/backup/qemu/util/error.c:109
>     #7 0x55ee1cef066e in qio_channel_socket_writev /mnt/sdb/backup/qemu/io/channel-socket.c:569
>     #8 0x55ee1cee806b in qio_channel_writev /mnt/sdb/backup/qemu/io/channel.c:207
>     #9 0x55ee1cee806b in qio_channel_writev_all /mnt/sdb/backup/qemu/io/channel.c:171
>     #10 0x55ee1cee8248 in qio_channel_write_all /mnt/sdb/backup/qemu/io/channel.c:257
>     #11 0x55ee1ca12c9a in multifd_send_thread /mnt/sdb/backup/qemu/migration/multifd.c:657
>     #12 0x55ee1d0607fc in qemu_thread_start /mnt/sdb/backup/qemu/util/qemu-thread-posix.c:519
>     #13 0x7f78159ae2dd in start_thread (/lib64/libpthread.so.0+0x82dd)
>     #14 0x7f78156df4b2 in __GI___clone (/lib64/libc.so.6+0xfc4b2)
>
> Reported-by: Euler Robot <euler.robot@huawei.com>
> Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>

Reviewed-by: Juan Quintela <quintela@redhat.com>