Reject empty schedules (num_entries == 0) so next_entry is always valid and
RCU readers/timer logic never walk an empty list. taprio enforces the same
constraint on schedules (sch_taprio.c, commit 09dbdf28f9f9fa).
Fixes: a51c328df310 ("net: qos: introduce a gate control flow action")
Signed-off-by: Paul Moses <redacted>
Cc: <redacted>
---
net/sched/act_gate.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/net/sched/act_gate.c b/net/sched/act_gate.c
index 48ff378bb051a..e4134b9a4a314 100644
--- a/net/sched/act_gate.c
+++ b/net/sched/act_gate.c
@@ -509,6 +509,12 @@ static int tcf_gate_init(struct net *net, struct nlattr *nla,
cycletime_ext = nla_get_u64(tb[TCA_GATE_CYCLE_TIME_EXT]);
p->tcfg_cycletime_ext = cycletime_ext;
+ if (p->num_entries == 0) {
+ NL_SET_ERR_MSG(extack, "The entry list is empty");
+ err = -EINVAL;
+ goto release_mem;
+ }
+
err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
if (err < 0)
goto release_mem;--
2.52.GIT