Re: [PATCH net 2/2] selftests: tc-testing: add TCA_STAB overhead rejection tests for DRR and ETS

On Tue, Aug 18, 2026 at 6:17 AM Jamal Hadi Salim <[email protected]> wrote:
>
> Add tdc test cases that verify a qdisc with an oversized TCA_STAB
> overhead (2147483000) is rejected. Without the fix, the qdisc is
> accepted and a single packet drives the deficit loop into a soft
> lockup; with the fix, the add fails with -EINVAL.
>
> Reported-by: [email protected]
> Tested-by: Victor Nogueira <[email protected]>
> Signed-off-by: Jamal Hadi Salim <[email protected]>
> ---
>  .../tc-testing/tc-tests/qdiscs/drr.json       | 20 +++++++++++++++++++
>  .../tc-testing/tc-tests/qdiscs/ets.json       | 20 +++++++++++++++++++
>  2 files changed, 40 insertions(+)
>
> diff --git a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/drr.json b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/drr.json
> index 2b61d8d79bde..7713eb35aaeb 100644
> --- a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/drr.json
> +++ b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/drr.json
> @@ -86,5 +86,25 @@
>          "teardown": [
>              "$TC qdisc del dev $DUMMY root"
>          ]
> +    },
> +    {
> +        "id": "d1e2",
> +        "name": "Reject DRR qdisc with oversized TCA_STAB overhead",
> +        "category": [
> +            "qdisc",
> +            "drr"
> +        ],
> +        "plugins": {
> +            "requires": "nsPlugin"
> +        },
> +        "setup": [
> +        ],
> +        "cmdUnderTest": "$TC qdisc add dev $DUMMY handle 1: root stab overhead 2147483000 drr",
> +        "expExitCode": "2",
> +        "verifyCmd": "$TC qdisc show dev $DUMMY",
> +        "matchPattern": "qdisc drr",
> +        "matchCount": "0",
> +        "teardown": [
> +        ]
>      }
>  ]
> diff --git a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/ets.json b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/ets.json
> index ee09e6d6fdf3..da7ae626f7e1 100644
> --- a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/ets.json
> +++ b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/ets.json
> @@ -1007,5 +1007,25 @@
>          "teardown": [
>              "echo \"1\" > /sys/bus/netdevsim/del_device"
>          ]
> +    },
> +    {
> +        "id": "f3a4",
> +        "name": "Reject ETS qdisc with oversized TCA_STAB overhead",
> +        "category": [
> +            "qdisc",
> +            "ets"
> +        ],
> +        "plugins": {
> +            "requires": "nsPlugin"
> +        },
> +        "setup": [
> +        ],
> +        "cmdUnderTest": "$TC qdisc add dev $DUMMY handle 1: root stab overhead 2147483000 ets bands 1 strict 0 quanta 1",
> +        "expExitCode": "2",
> +        "verifyCmd": "$TC qdisc show dev $DUMMY",
> +        "matchPattern": "qdisc ets",
> +        "matchCount": "0",
> +        "teardown": [
> +        ]
>      }
>  ]
> --
> 2.43.0

V2 had a different title.
--
pw-bot: cr

>