On Sat 16 Feb 2019 at 00:24, Cong Wang <xiyou.wangc...@gmail.com> wrote: > On Fri, Feb 15, 2019 at 4:11 AM Vlad Buslov <vla...@mellanox.com> wrote: >> >> Check that filter is not NULL before passing it to tcf_walker->fn() >> callback. This can happen when mall_change() failed to offload filter to >> hardware. >> >> Signed-off-by: Vlad Buslov <vla...@mellanox.com> >> --- >> net/sched/cls_matchall.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/net/sched/cls_matchall.c b/net/sched/cls_matchall.c >> index a37137430e61..1f9d481b0fbb 100644 >> --- a/net/sched/cls_matchall.c >> +++ b/net/sched/cls_matchall.c >> @@ -247,6 +247,9 @@ static void mall_walk(struct tcf_proto *tp, struct >> tcf_walker *arg, >> >> if (arg->count < arg->skip) >> goto skip; >> + >> + if (!head) >> + return; > > So head==NULL still counts one given that you check NULL after > checking arg->count. Is this expected?
My intention was to fix the problem (arg->fn() call with NULL filter) without changing any other functionality, and always incrementing arg->count once seemed to be the intended behavior. However, since mall_delete() just returns -EOPNOTSUPP, it might be the case that author of matchall expected to always have single filter configured when cls API calls mall_walk(). What would you suggest?
