vxcan1: j1939_tp_rxtimer: 0xffff88802b39b400: Timeout. Failed to send simple message. rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8993/1:b..l rcu: (detected by 0, t=10502 jiffies, g=34897, q=1639 ncpus=2) task:syz.1.869 state:R running task stack:23592 pid:8993 tgid:8993 ppid:5824 task_flags:0x40064c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7188 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7512 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:memcg1_uncharge_batch+0xe4/0x120 mm/memcontrol-v1.c:718 Code: 80 3c 02 00 75 4a 44 89 ee 48 89 df 48 8b 83 c0 0b 00 00 65 4c 01 20 e8 4a d2 ff ff e8 e5 ae 92 ff 9c 58 f6 c4 02 75 17 fb 5b <5d> 41 5c 41 5d c3 cc cc cc cc 5b 5d 41 5c 41 5d e9 d7 1f 1a 09 e8 RSP: 0018:ffffc900031b7198 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffffc900031b7230 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8df562a9 RDI: ffffffff8c1c1300 RBP: 000000000000001f R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 000000000000001f R13: 0000000000000000 R14: dffffc0000000000 R15: ffffc900031b75b8 uncharge_batch+0xe8/0x430 mm/memcontrol.c:5126 __mem_cgroup_uncharge_folios+0x142/0x1e0 mm/memcontrol.c:5201 mem_cgroup_uncharge_folios include/linux/memcontrol.h:672 [inline] folios_put_refs+0x564/0xa90 mm/swap.c:1007 folio_batch_release include/linux/folio_batch.h:101 [inline] shmem_undo_range+0x5e5/0x1570 mm/shmem.c:1149 shmem_truncate_range mm/shmem.c:1277 [inline] shmem_evict_inode+0x3f3/0xc40 mm/shmem.c:1407 evict+0x3c2/0xad0 fs/inode.c:841 iput_final fs/inode.c:1960 [inline] iput.part.0+0x605/0xf50 fs/inode.c:2009 iput+0x35/0x40 fs/inode.c:1975 dentry_unlink_inode+0x2a1/0x490 fs/dcache.c:467 __dentry_kill+0x1d0/0x600 fs/dcache.c:670 finish_dput+0x76/0x480 fs/dcache.c:879 dput.part.0+0x456/0x570 fs/dcache.c:928 dput+0x1f/0x30 fs/dcache.c:920 __fput+0x519/0xb50 fs/file_table.c:518 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x8d2/0x2a60 kernel/exit.c:975 do_group_exit+0xd5/0x2a0 kernel/exit.c:1117 get_signal+0x1ec7/0x21e0 kernel/signal.c:3037 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop kernel/entry/common.c:98 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:252 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:323 [inline] irqentry_exit+0x403/0x790 kernel/entry/common.c:162 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f2350e527f7 RSP: 002b:00007f234f1b61a0 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007f2350f9c819 RDX: 00007f234f1b61c0 RSI: 00007f234f1b62f0 RDI: 000000000000000b RBP: 00007f2351032c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007f2351216128 R14: 00007f2351216090 R15: 00007ffe2a0cfb78 rcu: rcu_preempt kthread starved for 5413 jiffies! g34897 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:28904 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7282 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 6482 Comm: kworker/u8:22 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker RIP: 0010:trylock_clear_pending kernel/locking/qspinlock_paravirt.h:124 [inline] RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:431 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x415/0xc00 kernel/locking/qspinlock.c:325 Code: 00 80 00 00 48 8d 84 24 80 00 00 00 48 c1 e9 03 41 83 e7 07 48 89 44 24 10 4c 8d 2c 29 b9 00 01 00 00 66 89 8c 24 80 00 00 00 <41> 0f b6 45 00 44 38 f8 7f 08 84 c0 0f 85 c8 06 00 00 0f b6 03 84 RSP: 0018:ffffc90000007608 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffff88802d86f940 RCX: 0000000000000100 RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff88802d86f942 RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffed1005b0df28 R10: ffff88802d86f943 R11: 0000000000000000 R12: 0000000000007b5e R13: ffffed1005b0df28 R14: ffff8880b843c200 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881242e7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555709054e8 CR3: 000000000e596000 CR4: 00000000003526f0 Call Trace: pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:35 [inline] queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:66 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x1e0/0x260 kernel/locking/spinlock_debug.c:116 spin_lock include/linux/spinlock.h:342 [inline] __netif_tx_lock include/linux/netdevice.h:4764 [inline] __dev_queue_xmit+0x19c4/0x4950 net/core/dev.c:4864 dev_queue_xmit include/linux/netdevice.h:3401 [inline] can_send+0x5d7/0xbd0 net/can/af_can.c:279 can_can_gw_rcv net/can/gw.c:569 [inline] can_can_gw_rcv+0x820/0xca0 net/can/gw.c:458 deliver net/can/af_can.c:575 [inline] can_rcv_filter+0x153/0x890 net/can/af_can.c:602 can_receive+0x2cb/0x500 net/can/af_can.c:674 can_rcv+0x29e/0x300 net/can/af_can.c:699 __netif_receive_skb_one_core+0x1b2/0x1e0 net/core/dev.c:6209 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6322 process_backlog+0x37a/0x1580 net/core/dev.c:6673 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7737 napi_poll net/core/dev.c:7800 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:7957 handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xac/0xe0 kernel/softirq.c:510 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] fpregs_unlock arch/x86/include/asm/fpu/api.h:77 [inline] kernel_fpu_end arch/x86/kernel/fpu/core.c:506 [inline] kernel_fpu_end+0x64/0x80 arch/x86/kernel/fpu/core.c:499 blake2s_compress+0x78/0xf0 lib/crypto/x86/blake2s.h:42 blake2s_update+0xef/0x320 lib/crypto/blake2s.c:119 hmac.constprop.0+0x33f/0x480 drivers/net/wireguard/noise.c:332 kdf.constprop.0+0x14d/0x280 drivers/net/wireguard/noise.c:367 message_ephemeral+0x5e/0x70 drivers/net/wireguard/noise.c:493 wg_noise_handshake_create_initiation+0x322/0x610 drivers/net/wireguard/noise.c:545 wg_packet_send_handshake_initiation+0x19c/0x360 drivers/net/wireguard/send.c:34 wg_packet_handshake_send_worker+0x1c/0x30 drivers/net/wireguard/send.c:51 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302 process_scheduled_works kernel/workqueue.c:3385 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 vxcan1: j1939_tp_rxtimer: 0xffff88802b398800: Timeout. Failed to send simple message.