rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5013/1:b..l (detected by 1, t=10503 jiffies, g=11269, q=348) task:syz-executor state:R running task stack:21824 pid: 5013 ppid: 5011 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6552 preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6577 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 vprintk_emit+0x149/0x150 kernel/printk/printk.c:2275 _printk+0xcc/0x110 kernel/printk/printk.c:2299 batadv_check_known_mac_addr+0x27e/0x3b0 net/batman-adv/hard-interface.c:524 batadv_hard_if_event+0x4a0/0x17e0 net/batman-adv/hard-interface.c:986 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2061 [inline] call_netdevice_notifiers net/core/dev.c:2075 [inline] dev_set_mac_address+0x2c4/0x3d0 net/core/dev.c:9114 dev_set_mac_address_user+0x2d/0x50 net/core/dev.c:9128 do_setlink+0x80d/0x3980 net/core/rtnetlink.c:2734 __rtnl_newlink net/core/rtnetlink.c:3450 [inline] rtnl_newlink+0x1419/0x17d0 net/core/rtnetlink.c:3572 rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2507 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] __sys_sendto+0x423/0x580 net/socket.c:2063 __do_sys_sendto net/socket.c:2075 [inline] __se_sys_sendto net/socket.c:2071 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2071 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f17b2faabbc RSP: 002b:00007ffd639ba310 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f17b3cc7620 RCX: 00007f17b2faabbc RDX: 000000000000002c RSI: 00007f17b3cc7670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffd639ba364 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f17b3cc7670 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10550 jiffies! g11269 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:27496 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5379 Comm: syz.3.19 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3682 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3701 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3756 [inline] RIP: 0010:__lock_acquire+0x16ec/0x7c60 kernel/locking/lockdep.c:5012 Code: df e9 65 ff ff ff 4c 8d 73 18 4c 89 f0 48 c1 e8 03 42 80 3c 00 00 74 12 4c 89 f7 e8 ce 15 60 00 49 b8 00 00 00 00 00 fc ff df <49> 8b 06 4c 39 e0 0f 84 2b 02 00 00 48 83 c3 08 48 89 d8 48 c1 e8 RSP: 0018:ffffc900000079e0 EFLAGS: 00000046 RAX: 1ffffffff1ff7097 RBX: ffffffff8ffb84a0 RCX: ffffffff815c0e00 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffb70c8 RBP: ffffc90000007c30 R08: dffffc0000000000 R09: fffffbfff1ff6e1a R10: fffffbfff1ff6e1a R11: 1ffffffff1ff6e19 R12: b8c2303ea99205dd R13: ffff888027028000 R14: ffffffff8ffb84b8 R15: ffff888027028b10 FS: 00007fcd960bd6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002006b000 CR3: 0000000073ee6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 seqcount_lockdep_reader_access+0xc6/0x1c0 include/linux/seqlock.h:103 timekeeping_get_delta kernel/time/timekeeping.c:254 [inline] timekeeping_get_ns kernel/time/timekeeping.c:388 [inline] ktime_get+0x7b/0x270 kernel/time/timekeeping.c:831 clockevents_program_event+0xe2/0x310 kernel/time/clockevents.c:326 hrtimer_interrupt+0x4de/0x8d0 kernel/time/hrtimer.c:1829 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: f6 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 7e db aa f7 48 89 df e8 46 b0 ab f7 e8 91 46 cc f7 fb bf 01 00 00 00 76 d4 9f f7 65 8b 05 17 d4 50 76 85 c0 74 02 5b c3 e8 c4 de 4e RSP: 0018:ffffc90002cefbc0 EFLAGS: 00000282 RAX: 876940f41633ed00 RBX: ffff888029ebef00 RCX: 876940f41633ed00 RDX: dffffc0000000000 RSI: ffffffff8a0b15c0 RDI: 0000000000000001 RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed10053d7de1 R10: ffffed10053d7de1 R11: 1ffff110053d7de0 R12: ffff888029ebef00 R13: 0000000000000021 R14: dffffc0000000000 R15: 000000001c000004 spin_unlock_irq include/linux/spinlock.h:413 [inline] get_signal+0x11d6/0x12c0 kernel/signal.c:2903 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fcd96e44d27 Code: ff ff 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 RSP: 002b:00007fcd960bd0e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007fcd97034fa8 RCX: 00007fcd96e44d29 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fcd97034fa8 RBP: 00007fcd97034fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcd97034fac R13: 0000000000000000 R14: 00007ffeeef2da70 R15: 00007ffeeef2db58 sched: RT throttling activated