rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2/1:b..l rcu: (detected by 0, t=10502 jiffies, g=93125, q=488 ncpus=2) task:kthreadd state:R running task stack:25864 pid:2 tgid:2 ppid:0 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767 preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:kasan_check_range+0x7/0x2a0 mm/kasan/generic.c:188 Code: df 7a e2 ff 90 0f 0b cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 55 41 57 <41> 56 41 54 53 b0 01 48 85 f6 0f 84 a0 01 00 00 4c 8d 04 37 49 39 RSP: 0018:ffffc90000077270 EFLAGS: 00000246 RAX: ffffc90000077f58 RBX: 0000000000000010 RCX: ffffffff816da656 RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc900000773d0 RBP: ffffc900000773d0 R08: 0000000000000011 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffc90000077380 R13: ffffc90000078000 R14: 0000000000000000 R15: ffffc90000070000 __asan_memset+0x23/0x50 mm/kasan/shadow.c:84 unwind_next_frame+0xb46/0x23b0 arch/x86/kernel/unwind_orc.c:592 arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122 save_stack+0xfc/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x1e0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] __free_frozen_pages+0xddf/0x10a0 mm/page_alloc.c:2725 discard_slab mm/slub.c:2730 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3199 put_cpu_partial+0x17e/0x250 mm/slub.c:3274 __slab_free+0x294/0x390 mm/slub.c:4526 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4161 [inline] slab_alloc_node mm/slub.c:4210 [inline] kmem_cache_alloc_noprof+0x1e1/0x390 mm/slub.c:4217 copy_sighand+0x50/0x230 kernel/fork.c:1856 copy_process+0x172c/0x3d10 kernel/fork.c:2423 kernel_clone+0x227/0x880 kernel/fork.c:2844 kernel_thread+0x1c2/0x250 kernel/fork.c:2906 create_kthread kernel/kthread.c:487 [inline] kthreadd+0x621/0x850 kernel/kthread.c:847 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 4372 jiffies! g93125 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:26688 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b7/0x940 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 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 1301 Comm: aoe_tx0 Not tainted 6.15.0-rc2-syzkaller-00404-g8560697b23dc #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data kernel/kcov.c:246 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x26/0x90 kernel/kcov.c:314 Code: 90 90 90 90 f3 0f 1e fa 4c 8b 04 24 65 48 8b 14 25 08 10 65 93 65 8b 05 98 50 a2 11 25 00 01 ff 00 74 10 3d 00 01 00 00 75 5b <83> ba 3c 16 00 00 00 74 52 8b 82 18 16 00 00 83 f8 03 75 47 48 8b RSP: 0018:ffffc90000a07f18 EFLAGS: 00000246 RAX: 0000000000000100 RBX: ffff8881528a2b40 RCX: ffff888027d5bc00 RDX: ffff888027d5bc00 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffffff8ae3ff4a R09: 1ffff1102a51456f R10: dffffc0000000000 R11: ffffed102a514570 R12: 0000000000000000 R13: dffffc0000000000 R14: ffff88807e231000 R15: ffff8881412d3000 FS: 0000000000000000(0000) GS:ffff8881250cf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffeddd4eff8 CR3: 00000000601a4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: maybe_deliver+0x5a/0x150 net/bridge/br_forward.c:182 br_flood+0x2e4/0x680 net/bridge/br_forward.c:237 br_handle_frame_finish+0x185b/0x1f60 net/bridge/br_input.c:220 br_nf_hook_thresh+0x482/0x5a0 net/bridge/br_netfilter_hooks.c:1170 br_nf_pre_routing_finish_ipv6+0xaa3/0xdd0 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x397/0x790 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:282 [inline] br_handle_frame+0x9fa/0x1530 net/bridge/br_input.c:433 __netif_receive_skb_core+0x155a/0x4bb0 net/core/dev.c:5773 __netif_receive_skb_one_core net/core/dev.c:5885 [inline] __netif_receive_skb+0x130/0x670 net/core/dev.c:6000 process_backlog+0x664/0x15c0 net/core/dev.c:6352 __napi_poll+0xcb/0x480 net/core/dev.c:7324 napi_poll net/core/dev.c:7388 [inline] net_rx_action+0x89d/0x1240 net/core/dev.c:7510 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xfb/0x220 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 aa 05 74 f5 48 89 df e8 e2 ae 74 f5 e8 ed 3a a0 f5 fb bf 01 00 00 00 12 90 65 f5 65 8b 05 3b 9e 3a 07 85 c0 74 06 5b c3 cc cc cc cc RSP: 0018:ffffc9000416fcc0 EFLAGS: 00000286 RAX: 8433c3fdf3e9bb00 RBX: ffffffff9aa76fe0 RCX: ffffffff81caabcc RDX: 0000000000000000 RSI: ffffffff8e635557 RDI: 0000000000000001 RBP: 000000000000000a R08: ffffffff905ebb77 R09: 1ffffffff20bd76e R10: dffffc0000000000 R11: fffffbfff20bd76f R12: ffff8880303d2000 R13: ffff888027d5d388 R14: dffffc0000000000 R15: ffffffff8cf0f640 spin_unlock_irq include/linux/spinlock.h:401 [inline] tx+0x46/0x180 drivers/block/aoe/aoenet.c:60 kthread+0x23c/0x470 drivers/block/aoe/aoecmd.c:1237 kthread+0x7b7/0x940 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 vkms_vblank_simulate: vblank timer overrun net_ratelimit: 4779 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:82:19:ac:92:b6:9b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:82:19:ac:92:b6:9b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) net_ratelimit: 5465 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:82:19:ac:92:b6:9b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:82:19:ac:92:b6:9b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:82:19:ac:92:b6:9b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)