[PATCH net 2/2] selftests: tc-testing: add u32 node ID pool exhaustion test
From: Jamal Hadi Salim <jhs@mojatatu.com>
Date: 2026-08-20 09:52:47
Also in:
stable
Subsystem:
kernel selftest framework, the rest · Maintainers:
Shuah Khan, Shuah Khan, Linus Torvalds
Add a tdc test case (7ec8) that fills the u32 node ID space with 4095
auto-generated handles, then attempts to add a 4096th. On the fixed
kernel the 4096th filter is rejected with ENOSPC (exit 2). On the
unfixed kernel it silently succeeds with a duplicate handle.
Fixes: e7614370d6f04 ("net_sched: use idr to allocate u32 filter handles")
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
---
.../tc-testing/tc-tests/filters/u32.json | 23 +++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/tools/testing/selftests/tc-testing/tc-tests/filters/u32.json b/tools/testing/selftests/tc-testing/tc-tests/filters/u32.json
index b2ca9d4e991b..b9019b14d05c 100644
--- a/tools/testing/selftests/tc-testing/tc-tests/filters/u32.json
+++ b/tools/testing/selftests/tc-testing/tc-tests/filters/u32.json@@ -353,5 +353,28 @@ "teardown": [ "$TC qdisc del dev $DEV1 parent root drr" ] + }, + { + "id": "7ec8", + "name": "Add u32 filter when node ID pool is exhausted (4096th filter rejected)", + "category": [ + "filter", + "u32" + ], + "plugins": { + "requires": "nsPlugin" + }, + "setup": [ + "$TC qdisc add dev $DUMMY clsact", + "yes 'filter add dev $DUMMY ingress prio 1 protocol ip u32 match u8 0 0 at 0' | head -n 4095 | $TC -b -" + ], + "cmdUnderTest": "$TC filter add dev $DUMMY ingress prio 1 protocol ip u32 match u8 0 0 at 0", + "expExitCode": "2", + "verifyCmd": "$TC filter show dev $DUMMY ingress", + "matchPattern": "pref 1 u32", + "matchCount": "4095", + "teardown": [ + "$TC qdisc del dev $DUMMY clsact" + ] } ]
--
2.43.0