rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6494/1:b..l rcu: (detected by 0, t=10502 jiffies, g=15789, q=218 ncpus=2) task:syz.3.139 state:R running task stack:21192 pid:6494 tgid:6491 ppid:5836 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5392 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6781 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7104 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:109 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline] RIP: 0010:unwind_next_frame+0x2b4/0x2390 arch/x86/kernel/unwind_orc.c:494 Code: 00 00 fc ff df 0f 84 03 02 00 00 4a 8d 14 ad b4 31 ad 8f 45 29 e8 4a 8d 1c 82 48 83 c3 fc 49 89 d5 48 39 da 0f 86 1c 10 00 00 <49> 29 d5 e9 80 00 00 00 31 db e9 eb 16 00 00 49 81 fc 00 10 03 91 RSP: 0018:ffffc90003fbe118 EFLAGS: 00000202 RAX: ffffffff8fbb5310 RBX: ffffffff8fbb5314 RCX: ffffffff8fbb5318 RDX: ffffffff8fbb5314 RSI: ffffffff903a8324 RDI: ffffffff8be191a0 RBP: ffffffff8fbb5318 R08: 0000000000000001 R09: ffffffff81727865 R10: ffffc90003fbe238 R11: ffffffff81acdb00 R12: ffffffff82166cfa R13: ffffffff8fbb5314 R14: ffffc90003fbe1e8 R15: ffffffff8fbb5314 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 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4147 [inline] slab_alloc_node mm/slub.c:4196 [inline] kmem_cache_alloc_node_noprof+0x1bb/0x3c0 mm/slub.c:4248 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1336 [inline] nlmsg_new include/net/netlink.h:1041 [inline] inet6_ifa_notify net/ipv6/addrconf.c:5614 [inline] __ipv6_ifa_notify+0x1e8/0xac0 net/ipv6/addrconf.c:6273 ipv6_ifa_notify net/ipv6/addrconf.c:6325 [inline] add_addr+0x1b8/0x2d0 net/ipv6/addrconf.c:3206 add_v4_addrs+0x70c/0xbd0 net/ipv6/addrconf.c:3262 addrconf_sit_config net/ipv6/addrconf.c:3514 [inline] addrconf_init_auto_addrs+0x39b/0xb50 net/ipv6/addrconf.c:3557 addrconf_notify+0xacc/0x1010 net/ipv6/addrconf.c:3744 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] __dev_notify_flags+0x18d/0x2e0 net/core/dev.c:-1 rtnl_configure_link net/core/rtnetlink.c:3589 [inline] rtnl_newlink_create+0x61c/0xb00 net/core/rtnetlink.c:3833 __rtnl_newlink net/core/rtnetlink.c:3940 [inline] rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4055 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x75b/0x8d0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:727 ____sys_sendmsg+0x505/0x830 net/socket.c:2566 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620 __sys_sendmsg net/socket.c:2652 [inline] __do_sys_sendmsg net/socket.c:2657 [inline] __se_sys_sendmsg net/socket.c:2655 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2655 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fab6d78e969 RSP: 002b:00007fab6e539038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fab6d9b6080 RCX: 00007fab6d78e969 RDX: 0000000020000000 RSI: 0000200000000480 RDI: 0000000000000005 RBP: 00007fab6d810ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fab6d9b6080 R15: 00007fffd6fc5578 rcu: rcu_preempt kthread timer wakeup didn't happen for 10488 jiffies! g15789 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=7127 rcu: rcu_preempt kthread starved for 10489 jiffies! g15789 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:27320 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5392 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6781 __schedule_loop kernel/sched/core.c:6859 [inline] schedule+0x165/0x360 kernel/sched/core.c:6874 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 0 Comm: swapper/1 Not tainted 6.15.0-syzkaller-09113-g8477ab143069 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:rcu_is_watching+0x67/0xb0 kernel/rcu/tree.c:746 Code: 89 f7 e8 6c 2d 7a 00 48 c7 c3 58 9f 99 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d 49 5b f1 10 <74> 11 83 e0 04 c1 e8 02 5b 41 5e 41 5f c3 cc cc cc cc cc e8 b1 71 RSP: 0018:ffffc90000a08cf8 EFLAGS: 00000002 RAX: 00000000004c01b5 RBX: ffff8880b8732f58 RCX: 6067c77b9ebb1100 RDX: ffff88801d28da00 RSI: ffffffff8be191e0 RDI: ffffffff8be191a0 RBP: ffffc90000a08e90 R08: ffffffff8f9f7ef7 R09: 1ffffffff1f3efde R10: dffffc0000000000 R11: fffffbfff1f3efdf R12: ffff88805ef66340 R13: dffffc0000000000 R14: ffffffff8db7fc68 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125d99000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000038000 CR3: 0000000021fd4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hrtimer_cancel include/trace/events/timer.h:317 [inline] debug_deactivate+0x80/0x200 kernel/time/hrtimer.c:491 __run_hrtimer kernel/time/hrtimer.c:1729 [inline] __hrtimer_run_queues+0x2b0/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 03 d5 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d c3 b2 2b 00 f3 0f 1e fa fb f4 d8 d4 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6 RAX: 6067c77b9ebb1100 RBX: ffffffff819752a8 RCX: 6067c77b9ebb1100 RDX: 0000000000000001 RSI: ffffffff8d95adbe RDI: ffffffff8be19200 RBP: ffffc90000197f20 R08: ffff8880b8732f5b R09: 1ffff110170e65eb R10: dffffc0000000000 R11: ffffed10170e65ec R12: ffffffff8f9f7ef0 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a51b40 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:743 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147