rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4296/1:b..l (detected by 1, t=10503 jiffies, g=14649, q=442) task:syz-executor.0 state:R running task stack:20096 pid: 4296 ppid: 4294 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6552 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6577 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 vprintk_emit+0x146/0x150 kernel/printk/printk.c:2275 _printk+0xd1/0x120 kernel/printk/printk.c:2299 batadv_check_known_mac_addr+0x28a/0x3d0 net/batman-adv/hard-interface.c:522 batadv_hard_if_event+0x300/0x17a0 net/batman-adv/hard-interface.c:986 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:391 call_netdevice_notifiers_info net/core/dev.c:2018 [inline] call_netdevice_notifiers_extack net/core/dev.c:2030 [inline] call_netdevice_notifiers net/core/dev.c:2044 [inline] dev_set_mac_address+0x325/0x470 net/core/dev.c:9074 dev_set_mac_address_user+0x2d/0x50 net/core/dev.c:9088 do_setlink+0x897/0x3b00 net/core/rtnetlink.c:2696 __rtnl_newlink net/core/rtnetlink.c:3429 [inline] rtnl_newlink+0x17a4/0x2070 net/core/rtnetlink.c:3549 rtnetlink_rcv_msg+0x993/0xee0 net/core/rtnetlink.c:5629 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2505 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1356 netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1924 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] __sys_sendto+0x564/0x720 net/socket.c:2058 __do_sys_sendto net/socket.c:2070 [inline] __se_sys_sendto net/socket.c:2066 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2066 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f111b79bbdc RSP: 002b:00007fff91005ca0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f111c3f1620 RCX: 00007f111b79bbdc RDX: 000000000000002c RSI: 00007f111c3f1670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007fff91005cf4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f111c3f1670 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10512 jiffies! g14649 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:27000 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 4535 Comm: syz-executor.3 Not tainted 5.15.159-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619 update_process_times+0x196/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1686 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627 Code: 2b 00 74 08 4c 89 f7 e8 fc 7c 67 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90003357ba0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200066af80 RCX: ffffffff81636502 RDX: dffffc0000000000 RSI: ffffffff8a8b3c20 RDI: ffffffff8ad8f680 RBP: ffffc90003357ce8 R08: dffffc0000000000 R09: fffffbfff1f7f01f R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200066af7c R13: dffffc0000000000 R14: ffffc90003357c00 R15: 0000000000000246 __might_fault+0xb4/0x110 mm/memory.c:5328 _copy_from_user+0x28/0x170 lib/usercopy.c:14 copy_from_user include/linux/uaccess.h:192 [inline] restore_altstack+0x9a/0x400 kernel/signal.c:4241 __do_sys_rt_sigreturn+0x19d/0x250 arch/x86/kernel/signal.c:677 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f0ce46ccee7 Code: 14 25 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 RSP: 002b:00007f0ce2c400c8 EFLAGS: 00000246 RAX: 0000000000000113 RBX: 00007f0ce47fbf80 RCX: 00007f0ce46ccee9 RDX: 0000000000000009 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 00007f0ce471949e R08: 0000000008000f28 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f0ce47fbf80 R15: 00007ffe295485e8 sched: RT throttling activated