rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4369/1:b..l (detected by 1, t=10502 jiffies, g=10617, q=260 ncpus=2) task:syz-executor state:R running task stack:20896 pid:4369 ppid:4357 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6727 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6751 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 vprintk_emit+0x683/0x740 kernel/printk/printk.c:2304 _printk+0xd1/0x111 kernel/printk/printk.c:2328 batadv_check_known_mac_addr+0x2aa/0x400 net/batman-adv/hard-interface.c:525 batadv_hard_if_event+0x300/0x1540 net/batman-adv/hard-interface.c:992 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:455 call_netdevice_notifiers_info net/core/dev.c:1970 [inline] call_netdevice_notifiers_extack net/core/dev.c:2008 [inline] call_netdevice_notifiers net/core/dev.c:2022 [inline] dev_set_mac_address+0x325/0x470 net/core/dev.c:8855 dev_set_mac_address_user+0x2d/0x50 net/core/dev.c:8869 do_setlink+0x7db/0x3de0 net/core/rtnetlink.c:2785 __rtnl_newlink net/core/rtnetlink.c:3605 [inline] rtnl_newlink+0x172c/0x2050 net/core/rtnetlink.c:3652 rtnetlink_rcv_msg+0x818/0xff0 net/core/rtnetlink.c:6150 netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2493 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline] netlink_unicast+0x7d8/0x970 net/netlink/af_netlink.c:1337 netlink_sendmsg+0xa26/0xd60 net/netlink/af_netlink.c:1859 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] __sys_sendto+0x480/0x600 net/socket.c:2153 __do_sys_sendto net/socket.c:2165 [inline] __se_sys_sendto net/socket.c:2161 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2161 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f552e78ebbc RSP: 002b:00007ffcefbca390 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f552f4d4620 RCX: 00007f552e78ebbc RDX: 000000000000002c RSI: 00007f552f4d4670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffcefbca3e4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f552f4d4670 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10544 jiffies! g10617 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:26712 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 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: 1 PID: 4476 Comm: syz.1.17 Not tainted 6.1.127-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: a1 95 f5 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 8e 87 ad f6 48 89 df e8 86 c5 ae f6 e8 11 1d d4 f6 fb bf 01 00 00 00 76 4f a1 f6 65 8b 05 17 2f 45 75 85 c0 74 02 5b c3 e8 c4 52 43 RSP: 0018:ffffc90003547b30 EFLAGS: 00000286 RAX: 0288a1a654121500 RBX: ffff88801a2d9bc0 RCX: ffffffff97357103 RDX: dffffc0000000000 RSI: ffffffff8b0c0340 RDI: 0000000000000001 RBP: ffffc90003547c70 R08: dffffc0000000000 R09: ffffed100345b379 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff1100345b3cb R13: 0000000004000000 R14: 0000000000000011 R15: ffff88801a2d9e58 FS: 00007f21ff17e6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2bf5ffff CR3: 00000000591af000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x154b/0x17d0 kernel/signal.c:2874 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f21fe38cd29 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:00007f21ff17e038 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007f21fe5a5fa0 RCX: 00007f21fe38cd29 RDX: 0000000020000300 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 00007f21fe40e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f21fe5a5fa0 R15: 00007ffdbe9f65c8