| Message ID | 20150203180518.GA3806@zenon.in.qult.net |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Tue, Feb 3, 2015 at 10:05 AM, Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr> wrote: > In tcf_exts_dump_stats(), ensure that exts->actions is not empty before > accessing the first element of that list and calling tcf_action_copy_stats() > on it. This fixes some random segvs when adding filters of type "basic" with > no particular action. > > This also fixes the dumping of those "no-action" filters, which more often > than not made calls to tcf_action_copy_stats() fail and consequently netlink > attributes added by the caller to be removed by a call to nla_nest_cancel(). > > Fixes: 33be62715991 ("net_sched: act: use standard struct list_head") > Signed-off-by: Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr> Acked-by: Cong Wang <cwang@twopensource.com> Thanks! -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index aad6a67..baef987 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -556,8 +556,9 @@ void tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst, } EXPORT_SYMBOL(tcf_exts_change); -#define tcf_exts_first_act(ext) \ - list_first_entry(&(exts)->actions, struct tc_action, list) +#define tcf_exts_first_act(ext) \ + list_first_entry_or_null(&(exts)->actions, \ + struct tc_action, list) int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts) { @@ -603,7 +604,7 @@ int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts) { #ifdef CONFIG_NET_CLS_ACT struct tc_action *a = tcf_exts_first_act(exts); - if (tcf_action_copy_stats(skb, a, 1) < 0) + if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0) return -1; #endif return 0;
In tcf_exts_dump_stats(), ensure that exts->actions is not empty before accessing the first element of that list and calling tcf_action_copy_stats() on it. This fixes some random segvs when adding filters of type "basic" with no particular action. This also fixes the dumping of those "no-action" filters, which more often than not made calls to tcf_action_copy_stats() fail and consequently netlink attributes added by the caller to be removed by a call to nla_nest_cancel(). Fixes: 33be62715991 ("net_sched: act: use standard struct list_head") Signed-off-by: Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr> --- net/sched/cls_api.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)