syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=90cc/1/0x4000000000000000 softirq=15354/15358 fqs=2
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P2963/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=10497, q=1751 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5905 Comm: kworker/1:6 Not tainted 6.15.0-rc7-syzkaller-00002-gb36ddb9210e6 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: mld mld_ifc_work
RIP: 0010:match_held_lock+0x3/0xc0 kernel/locking/lockdep.c:5303
Code: 5f e9 81 ca 02 00 cc e8 fb f8 ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 56 53 <bb> 01 00 00 00 48 39 77 10 74 6a 81 7f 20 00 00 20 00 72 5f 48 8b
RSP: 0018:ffffc90000a07a50 EFLAGS: 00000087
RAX: 0000000000000009 RBX: ffff88802eaf4768 RCX: 294916e980441100
RDX: ffff88802eaf3c00 RSI: ffff8880245df300 RDI: ffff88802eaf4768
RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000140f44 R12: 0000000000000046
R13: ffff88802eaf3c00 R14: ffff8880245df300 R15: 0000000000000003
FS:  0000000000000000(0000) GS:ffff8881261c2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3b03ad2110 CR3: 000000003247e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __lock_is_held kernel/locking/lockdep.c:5599 [inline]
 lock_is_held_type+0xa8/0x190 kernel/locking/lockdep.c:5938
 lock_is_held include/linux/lockdep.h:249 [inline]
 advance_sched+0xe7/0xc90 net/sched/sch_taprio.c:925
 __run_hrtimer kernel/time/hrtimer.c:1761 [inline]
 __hrtimer_run_queues+0x529/0xc60 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
 __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1055
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1049
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:unwind_next_frame+0x180c/0x2390 arch/x86/kernel/unwind_orc.c:665
Code: 85 f4 08 00 00 b3 01 8b 84 24 84 00 00 00 41 39 06 4c 8b 7c 24 48 48 8b 7c 24 70 0f 85 54 01 00 00 48 8b 44 24 58 80 3c 28 00 <74> 05 e8 bd 0a b0 00 4d 8b 66 38 49 8d 7e 08 48 89 f8 48 c1 e8 03
RSP: 0018:ffffc90000a07ef8 EFLAGS: 00000246
RAX: 1ffff92000141000 RBX: ffffffff909dcc01 RCX: 0000000000000001
RDX: ffffc90000a08008 RSI: dffffc0000000000 RDI: ffffc90000a08000
RBP: dffffc0000000000 R08: ffffc900048ef7d0 R09: 0000000000000000
R10: ffffc90000a08018 R11: fffff52000141005 R12: ffffc900048ef7d0
R13: ffffc90000a08018 R14: ffffc90000a07fc8 R15: ffffffff8171ca05
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2380 [inline]
 slab_free mm/slub.c:4642 [inline]
 kfree+0x193/0x440 mm/slub.c:4841
 skb_kfree_head net/core/skbuff.c:1058 [inline]
 skb_free_head net/core/skbuff.c:1070 [inline]
 skb_release_data+0x69a/0x890 net/core/skbuff.c:1097
 skb_release_all net/core/skbuff.c:1162 [inline]
 __kfree_skb net/core/skbuff.c:1176 [inline]
 sk_skb_reason_drop+0x127/0x170 net/core/skbuff.c:1214
 geneve_udp_encap_recv+0x7ca/0x2b70 drivers/net/geneve.c:-1
 udp_queue_rcv_one_skb+0x1654/0x1870 net/ipv4/udp.c:2385
 udp_unicast_rcv_skb+0x257/0x400 net/ipv4/udp.c:2623
 __udp4_lib_rcv+0x138f/0x2600 net/ipv4/udp.c:2699
 ip_protocol_deliver_rcu+0x282/0x440 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x2fb/0x580 net/ipv4/ip_input.c:233
 NF_HOOK+0x309/0x3a0 include/linux/netfilter.h:314
 NF_HOOK+0x309/0x3a0 include/linux/netfilter.h:314
 __netif_receive_skb_one_core net/core/dev.c:5887 [inline]
 __netif_receive_skb+0x143/0x380 net/core/dev.c:6000
 process_backlog+0x60e/0x14f0 net/core/dev.c:6352
 __napi_poll+0xc4/0x480 net/core/dev.c:7324
 napi_poll net/core/dev.c:7388 [inline]
 net_rx_action+0x6ea/0xdf0 net/core/dev.c:7510
 handle_softirqs+0x286/0x870 kernel/softirq.c:579
 do_softirq+0xec/0x180 kernel/softirq.c:480
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:910 [inline]
 __dev_queue_xmit+0x1cd7/0x3a70 net/core/dev.c:4656
 neigh_output include/net/neighbour.h:539 [inline]
 ip6_finish_output2+0x11fb/0x16a0 net/ipv6/ip6_output.c:141
 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline]
 ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:226
 NF_HOOK+0x9e/0x380 include/linux/netfilter.h:314
 mld_sendpack+0x800/0xd80 net/ipv6/mcast.c:1868
 mld_send_cr net/ipv6/mcast.c:2169 [inline]
 mld_ifc_work+0x835/0xde0 net/ipv6/mcast.c:2702
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
task:kworker/u8:7    state:R  running task     stack:24344 pid:2963  tgid:2963  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: events_unbound cfg80211_wiphy_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
 preempt_schedule_notrace+0xd1/0x110 kernel/sched/core.c:7040
 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
 rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:737
 rcu_read_lock include/linux/rcupdate.h:842 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0xd4/0x2390 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2380 [inline]
 slab_free mm/slub.c:4642 [inline]
 kfree+0x193/0x440 mm/slub.c:4841
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1582 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x11ef/0x2ae0 net/mac80211/ibss.c:1608
 ieee80211_iface_process_skb net/mac80211/iface.c:1625 [inline]
 ieee80211_iface_work+0x806/0xfe0 net/mac80211/iface.c:1679
 cfg80211_wiphy_work+0x2dc/0x460 net/wireless/core.c:435
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: rcu_preempt kthread starved for 10493 jiffies! g10497 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:27032 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2046
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted 6.15.0-rc7-syzkaller-00002-gb36ddb9210e6 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xe6e/0x11c0 kernel/smp.c:885
Code: 89 ee 83 e6 01 31 ff e8 80 6d 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 2b 69 0b 00 eb 37 f3 90 43 0f b6 04 2c <84> c0 75 10 41 f7 07 01 00 00 00 74 1e e8 10 69 0b 00 eb e5 44 89
RSP: 0018:ffffc90000127700 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b883ad40 RCX: ffff88801c6e0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000127860 R08: ffffffff8f7f3377 R09: 1ffffffff1efe66e
R10: dffffc0000000000 R11: fffffbfff1efe66f R12: 1ffff11017127e99
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b893f4c8
FS:  0000000000000000(0000) GS:ffff8881260c2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffeadf418a0 CR3: 000000000dd38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:2757 [inline]
 text_poke_bp_batch+0x319/0x940 arch/x86/kernel/alternative.c:2967
 text_poke_flush arch/x86/kernel/alternative.c:3158 [inline]
 text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:3165
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:850
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>