rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=fdec/1/0x4000000000000002 softirq=230193/230194 fqs=35 (detected by 0, t=10502 jiffies, g=388161, q=142 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 17626 Comm: syz.3.13552 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:207 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:147 [inline] RIP: 0010:wrmsr arch/x86/include/asm/msr.h:254 [inline] RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:206 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 ef 2f 01 03 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc900001e0288 EFLAGS: 00000046 RAX: 00000000000000f6 RBX: ffffffff8c64fb88 RCX: 000000000000083f RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f RBP: 0000000000000001 R08: ffffc900001e0207 R09: 1ffff9200003c040 R10: dffffc0000000000 R11: fffff5200003c041 R12: 0000000000000000 R13: dffffc0000000001 R14: dffffc0000000000 R15: 0000000000000001 FS: 00007f3f278266c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6b9e1b4d58 CR3: 0000000065f18000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000200000000300 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: arch_irq_work_raise+0x82/0xd0 arch/x86/kernel/irq_work.c:31 irq_work_queue_on+0x13c/0x260 kernel/irq_work.c:165 rcu_read_unlock_special+0x3c9/0x510 kernel/rcu/tree_plugin.h:678 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] trace_call_bpf+0x5bb/0x6b0 kernel/trace/bpf_trace.c:137 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:9997 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728 RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685 Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 92 30 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc900001e0740 EFLAGS: 00000206 RAX: 3b7b382c83883800 RBX: 1ffff9200003c0f0 RCX: 3b7b382c83883800 RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0c20 RBP: ffffc900001e0828 R08: ffffffff90af32ff R09: 1ffffffff215e65f R10: dffffc0000000000 R11: fffffbfff215e660 R12: 0000000000000246 R13: dffffc0000000000 R14: ffff8880b8f3b900 R15: 0000000000000002 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] __ip_queue_xmit+0x1174/0x1c10 net/ipv4/ip_output.c:539 __tcp_transmit_skb+0x1c92/0x31a0 net/ipv4/tcp_output.c:1405 tcp_delack_timer_handler+0x2a9/0x440 net/ipv4/tcp_timer.c:322 tcp_delack_timer+0x188/0x2e0 net/ipv4/tcp_timer.c:345 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x53e/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x2a1/0x930 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:27 Code: 48 8d bd 78 ff ff ff 4c 89 e6 4c 89 fa e8 86 b0 08 00 83 bd 78 ff ff ff 00 74 32 4c 8d bd 78 ff ff ff 4c 89 ff e8 6e 8c 08 00 <48> 85 c0 74 1e 48 89 df 48 89 c6 41 ff d6 84 c0 74 11 4c 89 ff e8 RSP: 0018:ffffc9000544ef48 EFLAGS: 00000246 RAX: ffffffff81d33bde RBX: ffffc9000544f000 RCX: 0000000080000000 RDX: ffffc9000544ef01 RSI: dffffc0000000000 RDI: ffffffff81d33bde RBP: ffffc9000544efd0 R08: ffffc9000544f2b8 R09: ffffc9000544ef98 R10: dffffc0000000000 R11: fffff52000a89df5 R12: ffff888058f15940 R13: 0000000000000000 R14: ffffffff81712560 R15: ffffc9000544ef48 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc_node+0xb0/0x240 mm/slab_common.c:943 kmalloc_node include/linux/slab.h:589 [inline] kvmalloc_node+0x6c/0x180 mm/util.c:581 kvmalloc include/linux/slab.h:716 [inline] kvmalloc_array include/linux/slab.h:734 [inline] kvcalloc include/linux/slab.h:739 [inline] check_cfg+0xd7/0x10a0 kernel/bpf/verifier.c:11148 bpf_check+0xafe8/0x10db0 kernel/bpf/verifier.c:15572 bpf_prog_load+0x101a/0x1560 kernel/bpf/syscall.c:2651 __sys_bpf+0x5b8/0x780 kernel/bpf/syscall.c:5030 __do_sys_bpf kernel/bpf/syscall.c:5134 [inline] __se_sys_bpf kernel/bpf/syscall.c:5132 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5132 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f3f2699aeb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3f27826028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f3f26c15fa0 RCX: 00007f3f2699aeb9 RDX: 0000000000000090 RSI: 0000200000000240 RDI: 0000000000000005 RBP: 00007f3f26a08c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3f26c16038 R14: 00007f3f26c15fa0 R15: 00007ffee0b68d08 rcu: rcu_preempt kthread timer wakeup didn't happen for 10426 jiffies! g388161 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=251799 rcu: rcu_preempt kthread starved for 10427 jiffies! g388161 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27472 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 4251 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] RIP: 0010:kvm_wait+0x159/0x1b0 arch/x86/kernel/kvm.c:1064 Code: 89 df 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 4b 0f b6 1f e8 37 38 50 00 44 38 e3 75 10 66 90 0f 00 2d 59 ce 50 09 fb f4 16 ff ff ff fb e9 10 ff ff ff e8 67 b1 f3 08 89 f9 80 e1 07 38 RSP: 0018:ffffc90003c078c0 EFLAGS: 00000246 RAX: ff07108b547f9900 RBX: 0000000000000003 RCX: ff07108b547f9900 RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0c20 RBP: ffffc90003c07970 R08: ffffffff90af32ff R09: 1ffffffff215e65f R10: dffffc0000000000 R11: fffffbfff215e660 R12: 0000000000000003 R13: ffff8880b8e3b954 R14: dffffc0000000000 R15: 1ffff92000780f18 FS: 0000555572027500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6b9ffe8600 CR3: 0000000077adb000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000008d24 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: pv_wait arch/x86/include/asm/paravirt.h:603 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline] __pv_queued_spin_lock_slowpath+0x616/0x9c0 kernel/locking/qspinlock.c:511 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x265/0x2f0 kernel/locking/spinlock_debug.c:115 spin_lock_bh include/linux/spinlock.h:356 [inline] lock_sock_nested+0x66/0x100 net/core/sock.c:3499 lock_sock include/net/sock.h:1805 [inline] tcp_sendmsg+0x1d/0x40 net/ipv4/tcp.c:1489 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] sock_write_iter+0x2d9/0x3e0 net/socket.c:1143 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x4b1/0xa30 fs/read_write.c:584 ksys_write+0x14c/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fd4bdb560d7 Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffe3ee4c560 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000555572027500 RCX: 00007fd4bdb560d7 RDX: 000000000000fd18 RSI: 00007fd4b91f02e8 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000fd18 R13: 000055557203ee50 R14: 00007ffe3ee4cb00 R15: 00007fd4b91f02e8