linux/net/sched
Eric Dumazet c040b99461 net/sched: fix lockdep splat in qdisc_tree_reduce_backlog()
commit 7eb322360b upstream.

qdisc_tree_reduce_backlog() is called with the qdisc lock held,
not RTNL.

We must use qdisc_lookup_rcu() instead of qdisc_lookup()

syzbot reported:

WARNING: suspicious RCU usage
6.1.74-syzkaller #0 Not tainted
-----------------------------
net/sched/sch_api.c:305 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
3 locks held by udevd/1142:
  #0: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
  #0: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
  #0: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: net_tx_action+0x64a/0x970 net/core/dev.c:5282
  #1: ffff888171861108 (&sch->q.lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]
  #1: ffff888171861108 (&sch->q.lock){+.-.}-{2:2}, at: net_tx_action+0x754/0x970 net/core/dev.c:5297
  #2: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
  #2: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
  #2: ffffffff87c729a0 (rcu_read_lock){....}-{1:2}, at: qdisc_tree_reduce_backlog+0x84/0x580 net/sched/sch_api.c:792

stack backtrace:
CPU: 1 PID: 1142 Comm: udevd Not tainted 6.1.74-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 <TASK>
  [<ffffffff85b85f14>] __dump_stack lib/dump_stack.c:88 [inline]
  [<ffffffff85b85f14>] dump_stack_lvl+0x1b1/0x28f lib/dump_stack.c:106
  [<ffffffff85b86007>] dump_stack+0x15/0x1e lib/dump_stack.c:113
  [<ffffffff81802299>] lockdep_rcu_suspicious+0x1b9/0x260 kernel/locking/lockdep.c:6592
  [<ffffffff84f0054c>] qdisc_lookup+0xac/0x6f0 net/sched/sch_api.c:305
  [<ffffffff84f037c3>] qdisc_tree_reduce_backlog+0x243/0x580 net/sched/sch_api.c:811
  [<ffffffff84f5b78c>] pfifo_tail_enqueue+0x32c/0x4b0 net/sched/sch_fifo.c:51
  [<ffffffff84fbcf63>] qdisc_enqueue include/net/sch_generic.h:833 [inline]
  [<ffffffff84fbcf63>] netem_dequeue+0xeb3/0x15d0 net/sched/sch_netem.c:723
  [<ffffffff84eecab9>] dequeue_skb net/sched/sch_generic.c:292 [inline]
  [<ffffffff84eecab9>] qdisc_restart net/sched/sch_generic.c:397 [inline]
  [<ffffffff84eecab9>] __qdisc_run+0x249/0x1e60 net/sched/sch_generic.c:415
  [<ffffffff84d7aa96>] qdisc_run+0xd6/0x260 include/net/pkt_sched.h:125
  [<ffffffff84d85d29>] net_tx_action+0x7c9/0x970 net/core/dev.c:5313
  [<ffffffff85e002bd>] __do_softirq+0x2bd/0x9bd kernel/softirq.c:616
  [<ffffffff81568bca>] invoke_softirq kernel/softirq.c:447 [inline]
  [<ffffffff81568bca>] __irq_exit_rcu+0xca/0x230 kernel/softirq.c:700
  [<ffffffff81568ae9>] irq_exit_rcu+0x9/0x20 kernel/softirq.c:712
  [<ffffffff85b89f52>] sysvec_apic_timer_interrupt+0x42/0x90 arch/x86/kernel/apic/apic.c:1107
  [<ffffffff85c00ccb>] asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:656

Fixes: d636fc5dd6 ("net: sched: add rcu annotations around qdisc->qdisc_sleeping")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20240402134133.2352776-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10 16:35:51 +02:00
..
act_api.c net: sched: Replace strlcpy with strscpy 2023-07-10 08:23:53 +01:00
act_bpf.c net/sched: avoid indirect act functions on retpoline kernels 2022-12-09 09:18:07 +00:00
act_connmark.c net/sched: act_connmark: handle errno on tcf_idr_check_alloc 2023-03-01 08:19:09 +00:00
act_csum.c net: skbuff: hide csum_not_inet when CONFIG_IP_SCTP not set 2023-04-19 13:04:30 +01:00
act_ct.c net/sched: act_ct: fix skb leak and crash on ooo frags 2024-01-25 15:35:30 -08:00
act_ctinfo.c net/sched: act_ctinfo: use percpu stats 2023-02-13 20:09:01 -08:00
act_gact.c Networking changes for 6.2. 2022-12-13 15:47:48 -08:00
act_gate.c net/sched: act_gate: use percpu stats 2023-02-16 10:39:28 +01:00
act_ife.c net/sched: avoid indirect act functions on retpoline kernels 2022-12-09 09:18:07 +00:00
act_ipt.c net/sched: act_ipt: zero skb->cb before calling target 2023-06-29 12:10:37 +02:00
act_meta_mark.c
act_meta_skbprio.c
act_meta_skbtcindex.c
act_mirred.c net/sched: act_mirred: don't override retval if we already lost the skb 2024-03-01 13:35:06 +01:00
act_mpls.c net/sched: remove two skb_mac_header() uses 2023-03-22 22:43:23 -07:00
act_nat.c net/sched: act_nat: transition to percpu stats and rcu 2023-02-16 10:39:28 +01:00
act_pedit.c net/sched: act_pedit: Add size check for TCA_PEDIT_PARMS_EX 2023-07-04 10:31:38 +02:00
act_police.c net: move gso declarations and functions to their own files 2023-06-10 00:11:41 -07:00
act_sample.c net/sched: act_sample: fix action bind logic 2023-02-26 18:27:45 +00:00
act_simple.c net/sched: avoid indirect act functions on retpoline kernels 2022-12-09 09:18:07 +00:00
act_skbedit.c net/sched: avoid indirect act functions on retpoline kernels 2022-12-09 09:18:07 +00:00
act_skbmod.c net/sched: act_skbmod: prevent kernel-infoleak 2024-04-10 16:35:51 +02:00
act_tunnel_key.c net/sched: act_tunnel_key: add support for "don't fragment" 2023-03-30 23:24:24 -07:00
act_vlan.c net/sched: avoid indirect act functions on retpoline kernels 2022-12-09 09:18:07 +00:00
cls_api.c net/sched: flower: Fix chain template offload 2024-01-31 16:19:02 -08:00
cls_basic.c net/sched: avoid indirect classify functions on retpoline kernels 2022-12-09 09:18:07 +00:00
cls_bpf.c net: sched: cls_bpf: Undo tcf_bind_filter in case of an error 2023-07-17 07:33:39 +01:00
cls_cgroup.c net/sched: avoid indirect classify functions on retpoline kernels 2022-12-09 09:18:07 +00:00
cls_flow.c treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
cls_flower.c net/sched: flower: Add lock protection when remove filter handle 2024-03-01 13:35:09 +01:00
cls_fw.c net/sched: cls_fw: No longer copy tcf_result on update to avoid use-after-free 2023-07-31 20:10:36 -07:00
cls_matchall.c net: sched: cls_matchall: Undo tcf_bind_filter in case of failure after mall_set_parms 2023-07-17 07:33:38 +01:00
cls_route.c net/sched: cls_route: No longer copy tcf_result on update to avoid use-after-free 2023-07-31 20:10:37 -07:00
cls_u32.c net: sched: cls_u32: Fix allocation size in u32_init() 2023-10-06 11:43:05 +01:00
em_canid.c
em_cmp.c net: sched: fix misspellings using misspell-fixer tool 2020-11-10 17:00:28 -08:00
em_ipset.c
em_ipt.c
em_meta.c net: annotate data-races around sk->sk_lingertime 2023-08-21 07:41:57 +01:00
em_nbyte.c net: sched: Return the correct errno code 2021-02-06 11:15:28 -08:00
em_text.c net: sched: em_text: fix possible memory leak in em_text_destroy() 2024-01-10 17:16:49 +01:00
em_u32.c
ematch.c net_sched: reject TCF_EM_SIMPLE case for complex ematch module 2022-12-19 09:43:18 +00:00
Kconfig bpf: Add fd-based tcx multi-prog infra with link support 2023-07-19 10:07:27 -07:00
Makefile net/sched: Retire rsvp classifier 2023-02-16 09:27:07 +01:00
sch_api.c net/sched: fix lockdep splat in qdisc_tree_reduce_backlog() 2024-04-10 16:35:51 +02:00
sch_blackhole.c
sch_cake.c net: move gso declarations and functions to their own files 2023-06-10 00:11:41 -07:00
sch_cbs.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_choke.c treewide: use get_random_u32_below() instead of deprecated function 2022-11-18 02:15:15 +01:00
sch_codel.c net: sched: remove redundant NULL check in change hook function 2022-09-01 08:06:45 +02:00
sch_drr.c net/sched: sch_drr: warn about class in use while deleting 2023-08-01 10:47:24 +02:00
sch_etf.c net: sched: etf: remove true check in etf_enable_offload() 2022-09-01 20:08:32 -07:00
sch_ets.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_fifo.c net_sched: fix NULL deref in fifo_set_limit() 2021-10-01 14:59:10 -07:00
sch_fq_codel.c Revert "net: sched: fq_codel: remove redundant resource cleanup in fq_codel_init()" 2022-10-19 13:47:09 +01:00
sch_fq_pie.c net/sched: fq_pie: avoid stalls in fq_pie_timer() 2023-08-31 11:21:52 +02:00
sch_fq.c net/sched: sch_fq: fix integer overflow of "credit" 2023-04-21 20:24:29 -07:00
sch_frag.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-12-31 14:35:40 +00:00
sch_generic.c net/sched: qdisc_destroy() old ingress and clsact Qdiscs before grafting 2023-06-14 10:31:39 +02:00
sch_gred.c net: sched: gred: prevent races when adding offloads to stats 2023-01-18 20:28:25 -08:00
sch_hfsc.c net/sched: sch_hfsc: upgrade 'rt' to 'sc' when it becomes a inner curve 2023-10-18 18:08:28 -07:00
sch_hhf.c net: sched: remove redundant NULL check in change hook function 2022-09-01 08:06:45 +02:00
sch_htb.c net/sched: sch_htb: warn about class in use while deleting 2023-08-01 10:47:24 +02:00
sch_ingress.c tcx: Fix splat in ingress_destroy upon tcx_entry_free 2023-07-24 11:42:35 -07:00
sch_mq.c net: sched: add rcu annotations around qdisc->qdisc_sleeping 2023-06-07 10:25:39 +01:00
sch_mqprio_lib.c net/sched: mqprio: allow per-TC user input of FP adminStatus 2023-04-13 22:22:10 -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_mqprio.c net/sched: mqprio: Add length check for TCA_MQPRIO_{MAX/MIN}_RATE64 2023-07-26 22:08:14 -07:00
sch_multiq.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_netem.c netem: use seeded PRNG for correlated loss events 2023-08-17 19:15:06 -07:00
sch_pie.c net: sched: add rcu annotations around qdisc->qdisc_sleeping 2023-06-07 10:25:39 +01:00
sch_plug.c net: sched: sch_qfq: Fix UAF in qfq_dequeue() 2023-09-05 08:54:12 +02:00
sch_prio.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_qfq.c net: sched: sch_qfq: Fix UAF in qfq_dequeue() 2023-09-05 08:54:12 +02:00
sch_red.c net: sched: add rcu annotations around qdisc->qdisc_sleeping 2023-06-07 10:25:39 +01:00
sch_sfb.c Networking fixes for 6.1-rc2, including fixes from netfilter 2022-10-20 17:24:59 -07:00
sch_sfq.c net: sched: add rcu annotations around qdisc->qdisc_sleeping 2023-06-07 10:25:39 +01:00
sch_skbprio.c net/sched: use tc_qdisc_stats_dump() in qdisc 2022-09-22 17:34:10 -07:00
sch_taprio.c net/sched: taprio: proper TCA_TAPRIO_TC_ENTRY_INDEX check 2024-03-26 18:20:08 -04:00
sch_tbf.c net: move gso declarations and functions to their own files 2023-06-10 00:11:41 -07:00
sch_teql.c net: sched: add rcu annotations around qdisc->qdisc_sleeping 2023-06-07 10:25:39 +01:00