linux/net/sched
Victor Nogueira 380ad8b7c6 net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks
commit 11cb63b0d1 upstream.

As Paolo said earlier [1]:

"Since the blamed commit below, classify can return TC_ACT_CONSUMED while
the current skb being held by the defragmentation engine. As reported by
GangMin Kim, if such packet is that may cause a UaF when the defrag engine
later on tries to tuch again such packet."

act_ct was never meant to be used in the egress path, however some users
are attaching it to egress today [2]. Attempting to reach a middle
ground, we noticed that, while most qdiscs are not handling
TC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we
address the issue by only allowing act_ct to bind to clsact/ingress
qdiscs and shared blocks. That way it's still possible to attach act_ct to
egress (albeit only with clsact).

[1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/
[2] https://lore.kernel.org/netdev/cc6bfb4a-4a2b-42d8-b9ce-7ef6644fb22b@ovn.org/

Reported-by: GangMin Kim <km.kim1503@gmail.com>
Fixes: 3f14b377d0 ("net/sched: act_ct: fix skb leak and crash on ooo frags")
CC: stable@vger.kernel.org
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260225134349.1287037-1-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2026-03-13 17:23:28 +01:00
..
act_api.c net/sched: act_api: avoid dereferencing ERR_PTR in tcf_idrinfo_destroy 2026-01-17 16:35:28 +01:00
act_bpf.c bpf: Add bpf_prog_run_data_pointers() 2025-11-14 08:56:49 -08:00
act_connmark.c net: sched: act_connmark: initialize struct tc_ife to fix kernel leak 2025-11-11 15:00:08 +01:00
act_csum.c net_sched: add back BH safety to tcf_lock 2025-09-02 15:51:45 -07:00
act_ct.c net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks 2026-03-13 17:23:28 +01:00
act_ctinfo.c net_sched: add back BH safety to tcf_lock 2025-09-02 15:51:45 -07:00
act_gact.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
act_gate.c net/sched: act_gate: snapshot parameters with RCU on replace 2026-03-13 17:23:28 +01:00
act_ife.c net/sched: act_ife: Fix metalist update behavior 2026-03-12 07:10:01 -04:00
act_meta_mark.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
act_meta_skbprio.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
act_meta_skbtcindex.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
act_mirred.c net/sched: act_mirred: Move the recursion counter struct netdev_xmit 2025-05-15 15:23:31 +02:00
act_mpls.c net_sched: add back BH safety to tcf_lock 2025-09-02 15:51:45 -07:00
act_nat.c net_sched: add back BH safety to tcf_lock 2025-09-02 15:51:45 -07:00
act_pedit.c net_sched: add back BH safety to tcf_lock 2025-09-02 15:51:45 -07:00
act_police.c net_sched: act_police: use RCU in tcf_police_dump() 2025-07-11 16:01:17 -07:00
act_sample.c net: sched: act_sample: add action cookie to sample 2024-07-05 17:45:47 -07:00
act_simple.c net/sched: Remove redundant memset(0) call in reset_policy() 2025-08-12 17:13:29 -07:00
act_skbedit.c net/sched: act_skbedit: fix divide-by-zero in tcf_skbedit_hash() 2026-03-04 07:21:33 -05:00
act_skbmod.c net_sched: add back BH safety to tcf_lock 2025-09-02 15:51:45 -07:00
act_tunnel_key.c net_sched: add back BH safety to tcf_lock 2025-09-02 15:51:45 -07:00
act_vlan.c net_sched: add back BH safety to tcf_lock 2025-09-02 15:51:45 -07:00
bpf_qdisc.c bpf: net_sched: Use the correct destructor kfunc type 2026-03-04 07:19:40 -05:00
cls_api.c net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks 2026-03-13 17:23:28 +01:00
cls_basic.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
cls_bpf.c bpf: Add bpf_prog_run_data_pointers() 2025-11-14 08:56:49 -08:00
cls_cgroup.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
cls_flow.c treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
cls_flower.c net: fix geneve_opt length integer overflow 2025-04-03 15:47:35 -07:00
cls_fw.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
cls_matchall.c net: sched: refine software bypass handling in tc_run 2025-01-20 09:21:27 +00:00
cls_route.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
cls_u32.c net/sched: cls_u32: use skb_header_pointer_careful() 2026-02-11 13:41:55 +01:00
em_canid.c net/sched: em_canid: fix uninit-value in em_canid_match 2025-11-26 16:28:10 +01:00
em_cmp.c net: sched: fix TCF_LAYER_TRANSPORT handling in tcf_get_base_ptr() 2025-11-24 18:53:14 -08:00
em_ipset.c sched: consistently handle layer3 header accesses in the presence of VLANs 2020-07-03 14:34:53 -07:00
em_ipt.c sched: consistently handle layer3 header accesses in the presence of VLANs 2020-07-03 14:34:53 -07:00
em_meta.c net: dismiss sk_forward_alloc_get() 2025-02-19 19:05:28 -08:00
em_nbyte.c net: sched: fix TCF_LAYER_TRANSPORT handling in tcf_get_base_ptr() 2025-11-24 18:53:14 -08:00
em_text.c net: sched: fix TCF_LAYER_TRANSPORT handling in tcf_get_base_ptr() 2025-11-24 18:53:14 -08:00
em_u32.c net: fill in MODULE_DESCRIPTION()s for net/sched 2024-02-09 14:12:02 -08:00
ematch.c net_sched: reject TCF_EM_SIMPLE case for complex ematch module 2022-12-19 09:43:18 +00:00
Kconfig sched: Add enqueue/dequeue of dualpi2 qdisc 2025-07-23 17:52:07 -07:00
Makefile sched: Add enqueue/dequeue of dualpi2 qdisc 2025-07-23 17:52:07 -07:00
sch_api.c net/sched: Abort __tc_modify_qdisc if parent is a clsact/ingress qdisc 2025-11-10 16:57:56 -08:00
sch_blackhole.c Revert "net: sched: Pass root lock to Qdisc_ops.enqueue" 2020-07-16 16:48:34 -07:00
sch_cake.c net/sched: sch_cake: Fix incorrect qlen reduction in cake_drop 2025-12-18 14:03:31 +01:00
sch_cbs.c net/sched: cbs: Fix integer overflow in cbs_set_port_rate() 2024-10-15 18:25:47 -07:00
sch_choke.c net: sched: fix ordering of qlen adjustment 2024-12-04 12:54:22 +00:00
sch_codel.c net/sched: Fix backlog accounting in qdisc_dequeue_internal 2025-08-14 17:52:29 -07:00
sch_drr.c net_sched: drr: Fix double list add in class with netem as child qdisc 2025-04-28 15:55:06 -07:00
sch_dualpi2.c net/sched: sch_dualpi2: Run prob update timer in softirq to avoid deadlock 2025-08-19 17:49:01 -07:00
sch_etf.c net_sched: sch_tfs: implement lockless etf_dump() 2024-04-19 11:34:07 +01:00
sch_ets.c net/sched: ets: fix divide by zero in the offload path 2026-03-12 07:09:41 -04:00
sch_fifo.c pfifo_tail_enqueue: Drop new packet when sch->limit == 0 2025-02-05 18:13:58 -08:00
sch_fq.c net_sched: sch_fq: clear q->band_pkt_count[] in fq_reset() 2026-03-12 07:09:58 -04:00
sch_fq_codel.c net/sched: Fix backlog accounting in qdisc_dequeue_internal 2025-08-14 17:52:29 -07:00
sch_fq_pie.c net/sched: Fix backlog accounting in qdisc_dequeue_internal 2025-08-14 17:52:29 -07:00
sch_frag.c net/sched: Use nested-BH locking for sch_frag_data_storage 2025-05-15 15:23:31 +02:00
sch_generic.c net_sched: limit try_bulk_dequeue_skb() batches 2025-11-11 17:56:50 -08:00
sch_gred.c sched: address a potential NULL pointer dereference in the GRED scheduler. 2025-03-06 16:35:14 -08:00
sch_hfsc.c net/sched: sch_qfq: Fix null-deref in agg_dequeue 2025-07-10 11:08:35 +02:00
sch_hhf.c net/sched: Fix backlog accounting in qdisc_dequeue_internal 2025-08-14 17:52:29 -07:00
sch_htb.c net/sched: Remove unnecessary WARNING condition for empty child qdisc in htb_activate 2025-08-20 19:27:08 -07:00
sch_ingress.c bpf: Fix too early release of tcx_entry 2024-07-08 14:07:31 -07:00
sch_mq.c net: sched: add rcu annotations around qdisc->qdisc_sleeping 2023-06-07 10:25:39 +01:00
sch_mqprio.c net/sched: mqprio: fix stack out-of-bounds write in tc entry parsing 2025-08-04 17:22:20 -07:00
sch_mqprio_lib.c net: sched: Fill in missing MODULE_DESCRIPTION for qdiscs 2023-11-01 21:49:09 -07:00
sch_mqprio_lib.h net/sched: mqprio: allow per-TC user input of FP adminStatus 2023-04-13 22:22:10 -07:00
sch_multiq.c net: sched: sch_multiq: fix possible OOB write in multiq_tune() 2024-06-05 10:50:19 +01:00
sch_netem.c net/sched: Restrict conditions for adding duplicating netems to qdisc tree 2025-07-11 15:50:21 -07:00
sch_pie.c net/sched: Fix backlog accounting in qdisc_dequeue_internal 2025-08-14 17:52:29 -07:00
sch_plug.c net/sched: Add module aliases for cls_,sch_,act_ modules 2024-02-02 10:57:55 -08:00
sch_prio.c net_sched: prio: fix a race in prio_tune() 2025-06-12 08:05:49 -07:00
sch_qfq.c net/sched: qfq: Use cl_is_active to determine whether class is active in qfq_rm_from_ag 2026-01-30 10:32:12 +01:00
sch_red.c Including fixes from bluetooth and wireless. 2025-06-12 09:50:36 -07:00
sch_sfb.c net/sched: Add drop reasons for AQM-based qdiscs 2024-12-17 13:27:29 +01:00
sch_sfq.c Including fixes from bluetooth and wireless. 2025-06-12 09:50:36 -07:00
sch_skbprio.c net_sched: skbprio: Remove overly strict queue assertions 2025-04-02 16:03:32 -07:00
sch_taprio.c net/sched: taprio: enforce minimum value for picos_per_byte 2025-08-01 15:15:28 -07:00
sch_tbf.c net_sched: tbf: fix a race in tbf_change() 2025-06-12 08:05:50 -07:00
sch_teql.c net/sched: Enforce that teql can only be used as root qdisc 2026-01-30 10:32:12 +01:00