Merge: net/sched: phase-2 backports for rhel-9.5

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/4624

JIRA: https://issues.redhat.com/browse/RHEL-44375  
JIRA: https://issues.redhat.com/browse/RHEL-45534  
  
CVE: CVE-2024-36244  
Upstream Status: All mainline in net.git.  
Tested: boot-tested only  
Conflicts: None  
  
Signed-off-by: Davide Caratti <dcaratti@redhat.com>

Approved-by: Xin Long <lxin@redhat.com>
Approved-by: Florian Westphal <fwestpha@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Lucas Zampieri <lzampier@redhat.com>

Author: zampierilucas

net/sched/act_api.c

@@ -830,7 +830,6 @@ int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
 	u32 max;
 
 	if (*index) {
-again:
 		rcu_read_lock();
 		p = idr_find(&idrinfo->action_idr, *index);
 
@@ -839,7 +838,7 @@ int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
 			 * index but did not assign the pointer yet.
 			 */
 			rcu_read_unlock();
-			goto again;
+			return -EAGAIN;
 		}
 
 		if (!p) {

net/sched/sch_taprio.c

@@ -1161,11 +1161,6 @@ static int parse_taprio_schedule(struct taprio_sched *q, struct nlattr **tb,
 		list_for_each_entry(entry, &new->entries, list)
 			cycle = ktime_add_ns(cycle, entry->interval);
 
-		if (!cycle) {
-			NL_SET_ERR_MSG(extack, "'cycle_time' can never be 0");
-			return -EINVAL;
-		}
-
 		if (cycle < 0 || cycle > INT_MAX) {
 			NL_SET_ERR_MSG(extack, "'cycle_time' is too big");
 			return -EINVAL;
@@ -1174,6 +1169,11 @@ static int parse_taprio_schedule(struct taprio_sched *q, struct nlattr **tb,
 		new->cycle_time = cycle;
 	}
 
+	if (new->cycle_time < new->num_entries * length_to_duration(q, ETH_ZLEN)) {
+		NL_SET_ERR_MSG(extack, "'cycle_time' is too small");
+		return -EINVAL;
+	}
+
 	taprio_calculate_gate_durations(q, new);
 
 	return 0;
@@ -1868,6 +1868,9 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
 
 	q->flags = err;
 
+	/* Needed for length_to_duration() during netlink attribute parsing */
+	taprio_set_picos_per_byte(dev, q);
+
 	err = taprio_parse_mqprio_opt(dev, mqprio, extack, q->flags);
 	if (err < 0)
 		return err;
@@ -1927,7 +1930,6 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
 	if (err < 0)
 		goto free_sched;
 
-	taprio_set_picos_per_byte(dev, q);
 	taprio_update_queue_max_sdu(q, new_admin, stab);
 
 	if (FULL_OFFLOAD_IS_ENABLED(q->flags))

tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json

@@ -132,6 +132,50 @@
             "echo \"1\" > /sys/bus/netdevsim/del_device"
         ]
     },
+    {
+        "id": "6f62",
+        "name": "Add taprio Qdisc with too short interval",
+        "category": [
+            "qdisc",
+            "taprio"
+        ],
+        "plugins": {
+            "requires": "nsPlugin"
+        },
+        "setup": [
+            "echo \"1 1 8\" > /sys/bus/netdevsim/new_device"
+        ],
+        "cmdUnderTest": "$TC qdisc add dev $ETH root handle 1: taprio num_tc 2 queues 1@0 1@1 sched-entry S 01 300 sched-entry S 02 1700 clockid CLOCK_TAI",
+        "expExitCode": "2",
+        "verifyCmd": "$TC qdisc show dev $ETH",
+        "matchPattern": "qdisc taprio 1: root refcnt",
+        "matchCount": "0",
+        "teardown": [
+            "echo \"1\" > /sys/bus/netdevsim/del_device"
+        ]
+    },
+    {
+        "id": "831f",
+        "name": "Add taprio Qdisc with too short cycle-time",
+        "category": [
+            "qdisc",
+            "taprio"
+        ],
+        "plugins": {
+            "requires": "nsPlugin"
+        },
+        "setup": [
+            "echo \"1 1 8\" > /sys/bus/netdevsim/new_device"
+        ],
+        "cmdUnderTest": "$TC qdisc add dev $ETH root handle 1: taprio num_tc 2 queues 1@0 1@1 sched-entry S 01 200000 sched-entry S 02 200000 cycle-time 100 clockid CLOCK_TAI",
+        "expExitCode": "2",
+        "verifyCmd": "$TC qdisc show dev $ETH",
+        "matchPattern": "qdisc taprio 1: root refcnt",
+        "matchCount": "0",
+        "teardown": [
+            "echo \"1\" > /sys/bus/netdevsim/del_device"
+        ]
+    },
     {
         "id": "3e1e",
         "name": "Add taprio Qdisc with an invalid cycle-time",