Re: [Patch net] team: avoid complex list operations in team_nl_cmd_options_set()

[Jiri Pirko <jiri@resnulli.us>]

Tue, Feb 12, 2019 at 06:59:51AM CET, xiyou.wangcong@gmail.com wrote:
>The current opt_inst_list operations inside team_nl_cmd_options_set()
>is too complex to track:
>
>    LIST_HEAD(opt_inst_list);
>    nla_for_each_nested(...) {
>        list_for_each_entry(opt_inst, &team->option_inst_list, list) {
>            if (__team_option_inst_tmp_find(&opt_inst_list, opt_inst))
>                continue;
>            list_add(&opt_inst->tmp_list, &opt_inst_list);
>        }
>    }
>    team_nl_send_event_options_get(team, &opt_inst_list);
>
>as while we retrieve 'opt_inst' from team->option_inst_list, it could
>be added to the local 'opt_inst_list' for multiple times. The
>__team_option_inst_tmp_find() doesn't work, as the setter
>team_mode_option_set() still calls team->ops.exit() which uses
>->tmp_list too in __team_options_change_check().
>
>Simplify the list operations by moving the 'opt_inst_list' and
>team_nl_send_event_options_get() into the nla_for_each_nested() loop so
>that it can be guranteed that we won't insert a same list entry for
>multiple times. Therefore, __team_option_inst_tmp_find() can be removed
>too.
>
>Fixes: 4fb0534fb7bb ("team: avoid adding twice the same option to the event list")
>Fixes: 2fcdb2c9e659 ("team: allow to send multiple set events in one message")
>Reported-by: syzbot+4d4af685432dc0e56c91@syzkaller.appspotmail.com
>Reported-by: syzbot+68ee510075cf64260cc4@syzkaller.appspotmail.com
>Cc: Jiri Pirko <jiri@resnulli.us>
>Cc: Paolo Abeni <pabeni@redhat.com>
>Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>

Acked-by: Jiri Pirko <jiri@mellanox.com>

Thanks!