From 478eb5abb51931a152abab068f8a717b7ff480fd Mon Sep 17 00:00:00 2001 From: Xuanqiang Luo Date: Wed, 9 Sep 2026 15:03:35 +0800 Subject: [PATCH 1/2] net/sched: act_api: release all action references on NEWACTION failure When a batched RTM_NEWACTION request replaces an existing action, tcf_idr_check_alloc() takes a temporary reference on it. If a later action fails to initialize, tcf_action_destroy() uses strict release semantics to clean up the actions initialized so far. For an action bound to a filter, the strict check returns -EPERM without dropping the temporary reference. This error also makes tcf_action_destroy() return before releasing subsequent entries. Any new action initialized between the bound action and the failing entry is leaked together with its reserved IDR slot, preventing reuse of its index. Use tcf_idr_release() to drop each reference held by the batch without rejecting bound actions. This allows cleanup to continue through all initialized entries and preserves the module reference release when an action is destroyed. Explicit action deletion and flushing retain their separate bind-count checks. Fixes: 55334a5db5cd ("net_sched: act: refuse to remove bound action outside") Cc: stable@vger.kernel.org Signed-off-by: Xuanqiang Luo Reviewed-by: Jamal Hadi Salim Link: https://patch.msgid.link/20260909070336.32979-2-xuanqiang.luo@linux.dev Signed-off-by: Jakub Kicinski --- net/sched/act_api.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/net/sched/act_api.c b/net/sched/act_api.c index 37eced84dfa5..19501dc99464 100644 --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -1200,18 +1200,13 @@ EXPORT_SYMBOL(tcf_action_exec); int tcf_action_destroy(struct tc_action *actions[], int bind) { - const struct tc_action_ops *ops; struct tc_action *a; int ret = 0, i; tcf_act_for_each_action(i, a, actions) { actions[i] = NULL; - ops = a->ops; - ret = __tcf_idr_release(a, bind, true); - if (ret == ACT_P_DELETED) - module_put(ops->owner); - else if (ret < 0) - return ret; + /* Drop our reference even if the action is still bound to a filter. */ + ret = tcf_idr_release(a, bind); } return ret; } From 2a86bbed9f60702e97a8194e40f90f4db22d7795 Mon Sep 17 00:00:00 2001 From: Xuanqiang Luo Date: Wed, 9 Sep 2026 15:03:36 +0800 Subject: [PATCH 2/2] selftests: tc-testing: test action batch failure cleanup Add tests for cleanup after a batched RTM_NEWACTION request fails. Replace an existing gact action bound to a filter, then fail a later entry by requesting goto chain without a classifier context. Check that the bound action's reference count returns to its original value. Also cover a successfully initialized new action between the bound action and the failing entry, verifying that its reserved index can be reused. Repeat the bound action in another batch to check that each temporary reference to the same action is released. Signed-off-by: Xuanqiang Luo Reviewed-by: Jamal Hadi Salim Link: https://patch.msgid.link/20260909070336.32979-3-xuanqiang.luo@linux.dev Signed-off-by: Jakub Kicinski --- .../tc-tests/actions/gact-rollback.json | 78 +++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 tools/testing/selftests/tc-testing/tc-tests/actions/gact-rollback.json diff --git a/tools/testing/selftests/tc-testing/tc-tests/actions/gact-rollback.json b/tools/testing/selftests/tc-testing/tc-tests/actions/gact-rollback.json new file mode 100644 index 000000000000..e92a4180db68 --- /dev/null +++ b/tools/testing/selftests/tc-testing/tc-tests/actions/gact-rollback.json @@ -0,0 +1,78 @@ +[ + { + "id": "e3b1", + "name": "Failed action batch releases a bound action reference", + "category": [ + "actions", + "gact" + ], + "plugins": { + "requires": "nsPlugin" + }, + "setup": [ + "$TC qdisc add dev $DEV1 ingress", + "$TC actions add action pass index 1", + "$TC filter add dev $DEV1 protocol all ingress prio 1 matchall action gact index 1" + ], + "cmdUnderTest": "$TC actions replace action pass index 1 action goto chain 42 index 3", + "expExitCode": "255", + "verifyCmd": "$TC actions ls action gact", + "matchPattern": "total acts 1.*index 1 ref 2 bind 1", + "matchCount": "1", + "teardown": [ + "$TC qdisc del dev $DEV1 ingress" + ] + }, + { + "id": "e3b2", + "name": "Failed action batch releases entries after a bound action", + "category": [ + "actions", + "gact" + ], + "plugins": { + "requires": "nsPlugin" + }, + "setup": [ + "$TC qdisc add dev $DEV1 ingress", + "$TC actions add action pass index 1", + "$TC filter add dev $DEV1 protocol all ingress prio 1 matchall action gact index 1", + [ + "$TC actions replace action pass index 1 action pass index 2 action goto chain 42 index 3", + 255 + ] + ], + "cmdUnderTest": "$TC actions add action pass index 2", + "expExitCode": "0", + "verifyCmd": "$TC actions ls action gact", + "matchPattern": "total acts 2.*index 1 ref 2 bind 1.*index 2 ref 1 bind 0", + "matchCount": "1", + "teardown": [ + "$TC qdisc del dev $DEV1 ingress" + ] + }, + { + "id": "e3b3", + "name": "Failed action batch releases repeated references to a bound action", + "category": [ + "actions", + "gact" + ], + "plugins": { + "requires": "nsPlugin" + }, + "setup": [ + "$TC qdisc add dev $DEV1 ingress", + "$TC actions add action pass index 1", + "$TC filter add dev $DEV1 protocol all ingress prio 1 matchall action gact index 1" + ], + "cmdUnderTest": "$TC actions replace action pass index 1 action pass index 1 action goto chain 42 index 3", + "expExitCode": "255", + "verifyCmd": "$TC actions ls action gact", + "matchPattern": "total acts 1.*index 1 ref 2 bind 1", + "matchCount": "1", + "teardown": [ + "$TC qdisc del dev $DEV1 ingress" + ] + } +]