rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (10337 ticks this GP) idle=3bdc/1/0x4000000000000000 softirq=55022/55023 fqs=1104 rcu: hardirqs softirqs csw/system rcu: number: 1102557 0 0 rcu: cputime: 11181 27441 28 ==> 38660(ms) rcu: (t=10504 jiffies g=72409 q=917 ncpus=2) rcu: rcu_preempt kthread timer wakeup didn't happen for 851 jiffies! g72409 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=40574 rcu: rcu_preempt kthread starved for 854 jiffies! g72409 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26824 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x160/0x280 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5748 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148 Code: cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 23 bb 40 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56 RSP: 0018:ffffc900043e76f8 EFLAGS: 000002d3 RAX: ffffffff813a13aa RBX: 0000000000000003 RCX: ffff888077839e00 RDX: 0000000000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f80 RBP: ffffc900043e77d0 R08: ffffffff90d945c7 R09: 1ffffffff21b28b8 R10: dffffc0000000000 R11: fffffbfff21b28b9 R12: dffffc0000000000 R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff9200087cee4 FS: 0000555590529500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff2528bc80 CR3: 00000000770d7000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000200000000300 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] kvm_wait+0x22f/0x290 arch/x86/kernel/kvm.c:1058 pv_wait arch/x86/include/asm/paravirt.h:598 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline] __pv_queued_spin_lock_slowpath+0x61a/0x9d0 kernel/locking/qspinlock.c:511 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x24e/0x2c0 kernel/locking/spinlock_debug.c:115 spin_lock_bh include/linux/spinlock.h:356 [inline] lock_sock_nested+0x6a/0x100 net/core/sock.c:3538 lock_sock include/net/sock.h:1767 [inline] tcp_recvmsg+0x1fa/0x810 net/ipv4/tcp.c:2603 inet_recvmsg+0x130/0x1e0 net/ipv4/af_inet.c:882 sock_recvmsg_nosec net/socket.c:1046 [inline] sock_recvmsg net/socket.c:1068 [inline] sock_read_iter+0x2b7/0x3b0 net/socket.c:1138 call_read_iter include/linux/fs.h:2012 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x431/0x920 fs/read_write.c:470 ksys_read+0x147/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fbc4318e11d Code: a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb bd e8 a8 48 00 00 0f 1f 84 00 00 00 00 00 80 3d 41 d4 22 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec RSP: 002b:00007ffd8dbb0ff8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007ffd8dbb1550 RCX: 00007fbc4318e11d RDX: 0000000000000004 RSI: 00007ffd8dbb100c RDI: 0000000000000003 RBP: 0000000000000000 R08: 000000000000027a R09: 0000000000745a85 R10: 00000147294feac4 R11: 0000000000000246 R12: 00007ffd8dbb1420 R13: 0000000000000004 R14: 00007ffd8dbb100c R15: 00007ffd8dbb10a0 CPU: 0 PID: 14957 Comm: syz.1.2422 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:60 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:178 [inline] RIP: 0010:kasan_check_range+0x52/0x290 mm/kasan/generic.c:187 Code: f9 49 c1 e9 2f 41 81 f9 ff ff 01 00 0f 82 46 02 00 00 49 89 ff 49 c1 ef 03 49 ba 00 00 00 00 00 fc ff df 4f 8d 1c 17 49 ff c8 <4d> 89 c1 49 c1 e9 03 48 bb 01 00 00 00 00 fc ff df 4d 8d 34 19 4d RSP: 0018:ffffc90000005e40 EFLAGS: 00000282 RAX: ffffc90000006f01 RBX: 0000000000000010 RCX: ffffffff813ab988 RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc90000005fb8 RBP: 0000000000000000 R08: ffffc90000005fc7 R09: 000000000001ffff R10: dffffc0000000000 R11: fffff52000000bf7 R12: ffffc90000005f68 R13: dffffc0000000000 R14: ffffc90000005fb8 R15: 1ffff92000000bf7 FS: 00007f3f312ae6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000100000001 CR3: 000000005f1f2000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __asan_memset+0x22/0x40 mm/kasan/shadow.c:84 unwind_next_frame+0x1648/0x2970 arch/x86/kernel/unwind_orc.c:592 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x280 mm/slub.c:3852 skb_kfree_head net/core/skbuff.c:947 [inline] skb_free_head net/core/skbuff.c:961 [inline] skb_release_data+0x60a/0x800 net/core/skbuff.c:991 skb_release_all net/core/skbuff.c:1057 [inline] __kfree_skb net/core/skbuff.c:1071 [inline] kfree_skb_reason+0x10e/0x170 net/core/skbuff.c:1107 dev_kfree_skb_any_reason+0x10c/0x120 net/core/dev.c:3228 free_old_xmit_skbs+0x114/0x3c0 drivers/net/virtio_net.c:780 start_xmit+0x161/0x1420 drivers/net/virtio_net.c:2420 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3619 [inline] dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3635 sch_direct_xmit+0x252/0x4a0 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:3856 [inline] __dev_queue_xmit+0x173e/0x35a0 net/core/dev.c:4391 neigh_output include/net/neighbour.h:543 [inline] ip_finish_output2+0xd21/0x11d0 net/ipv4/ip_output.c:235 dst_output include/net/dst.h:467 [inline] ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x10aa/0x1a10 net/ipv4/ip_output.c:535 __tcp_transmit_skb+0x1c97/0x32a0 net/ipv4/tcp_output.c:1422 tcp_rcv_established+0x12e3/0x1cf0 net/ipv4/tcp_input.c:6134 tcp_v4_do_rcv+0x4ed/0xb80 net/ipv4/tcp_ipv4.c:1734 tcp_v4_rcv+0x2334/0x2a50 net/ipv4/tcp_ipv4.c:2166 ip_protocol_deliver_rcu+0x20e/0x3f0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2ca/0x510 net/ipv4/ip_input.c:233 NF_HOOK+0x303/0x390 include/linux/netfilter.h:304 dst_input include/net/dst.h:477 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline] ip_sublist_rcv+0xa38/0xd20 net/ipv4/ip_input.c:639 ip_list_rcv+0x3e3/0x430 net/ipv4/ip_input.c:674 __netif_receive_skb_list_ptype net/core/dev.c:5651 [inline] __netif_receive_skb_list_core+0x2cc/0x740 net/core/dev.c:5689 __netif_receive_skb_list net/core/dev.c:5751 [inline] netif_receive_skb_list_internal+0x91b/0xc60 net/core/dev.c:5842 gro_normal_list include/net/gro.h:451 [inline] gro_normal_one include/net/gro.h:464 [inline] napi_skb_finish net/core/gro.c:573 [inline] napi_gro_receive+0x565/0xb00 net/core/gro.c:603 receive_buf+0x218c/0x3780 drivers/net/virtio_net.c:1870 virtnet_receive drivers/net/virtio_net.c:2155 [inline] virtnet_poll+0x61f/0x1180 drivers/net/virtio_net.c:2229 __napi_poll+0xc0/0x460 net/core/dev.c:6612 napi_poll net/core/dev.c:6679 [inline] net_rx_action+0x5ea/0xbf0 net/core/dev.c:6815 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:preempt_schedule_irq+0xb0/0x140 kernel/sched/core.c:7009 Code: 44 24 20 f6 44 24 21 02 74 0b 0f 0b 48 f7 03 08 00 00 00 74 63 bf 01 00 00 00 e8 8b b3 eb f6 e8 26 3a 1c f7 fb bf 01 00 00 00 db b5 ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24 RSP: 0018:ffffc90004b8fbe0 EFLAGS: 00000282 RAX: 8217248a192d6400 RBX: 0000000000000000 RCX: 8217248a192d6400 RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: 0000000000000001 RBP: ffffc90004b8fc90 R08: ffffffff8e4a212f R09: 1ffffffff1c94425 R10: dffffc0000000000 R11: fffffbfff1c94426 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000971f7c irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:should_fail_ex+0x4/0x4d0 lib/fault-inject.c:104 Code: 80 e1 07 80 c1 03 38 c1 0f 8c 6c ff ff ff 48 89 df e8 50 c1 8c fd e9 5f ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 66 0f 1f 00 <55> 41 57 41 56 41 55 41 54 53 48 83 ec 18 89 14 24 49 89 f6 48 89 RSP: 0018:ffffc90004b8fd50 EFLAGS: 00000246 RAX: ffffffff845050a9 RBX: 0000000000000090 RCX: 0000000000080000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8d3e5940 RBP: ffffc90004b8fee8 R08: ffffffff8e4a212f R09: 1ffffffff1c94425 R10: dffffc0000000000 R11: fffffbfff1c94426 R12: dffffc0000000000 R13: 0000000000000090 R14: ffffc90004b8fdc0 R15: 0000200000000c80 _copy_from_user+0x2f/0xe0 lib/usercopy.c:15 copy_from_user include/linux/uaccess.h:183 [inline] copy_from_bpfptr_offset include/linux/bpfptr.h:53 [inline] copy_from_bpfptr include/linux/bpfptr.h:59 [inline] __sys_bpf+0x1e9/0x800 kernel/bpf/syscall.c:5446 __do_sys_bpf kernel/bpf/syscall.c:5577 [inline] __se_sys_bpf kernel/bpf/syscall.c:5575 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5575 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f3f3038f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3f312ae038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f3f305e6090 RCX: 00007f3f3038f749 RDX: 0000000000000094 RSI: 0000200000000c80 RDI: 0000000000000005 RBP: 00007f3f30413f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3f305e6128 R14: 00007f3f305e6090 R15: 00007fff5867b968