rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4775/1:b..l
	(detected by 1, t=10503 jiffies, g=11853, q=345)
task:syz-executor    state:R  running task     stack:21896 pid: 4775 ppid:  4768 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6571
 preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6596
 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: 0033:0x7f0c7b38dbbc
RSP: 002b:00007ffe1ad736a0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f0c7c0aa620 RCX: 00007f0c7b38dbbc
RDX: 000000000000002c RSI: 00007f0c7c0aa670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffe1ad736f4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f0c7c0aa670 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10539 jiffies! g11853 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:28032 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 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
 </TASK>
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: 5184 Comm: syz.4.52 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__lock_acquire+0x1cc/0x7c60 kernel/locking/lockdep.c:-1
Code: c7 c0 80 3f 0c 96 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 9e 64 00 00 83 3d 60 40 b0 14 00 75 0a 41 83 fc 30 0f 83 b0 57 00 00 <4c> 89 6c 24 30 44 8b 6d 20 48 c7 c0 80 4f 94 8f 49 29 c7 49 c1 ff
RSP: 0018:ffffc90002eef760 EFLAGS: 00000083
RAX: 0000000000000004 RBX: ffff88801686f828 RCX: ffffffff960c3f03
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801686f828
RBP: ffffc90002eef9b0 R08: dffffc0000000000 R09: 0000000000000000
R10: fffffbfff1ad32b6 R11: 1ffffffff1ad32b5 R12: 0000000000000000
R13: ffff88807d521dc0 R14: ffff88807d5228a8 R15: ffffffff8f958300
FS:  00007f82c80706c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002006b000 CR3: 000000007af9f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __might_fault+0xb3/0x110 mm/memory.c:5357
 __copy_from_user include/linux/uaccess.h:109 [inline]
 check_xstate_in_sigframe arch/x86/kernel/fpu/signal.c:33 [inline]
 __fpu_restore_sig arch/x86/kernel/fpu/signal.c:317 [inline]
 fpu__restore_sig+0x203/0xf50 arch/x86/kernel/fpu/signal.c:466
 restore_sigcontext arch/x86/kernel/signal.c:139 [inline]
 __ia32_sys_rt_sigreturn+0x649/0x790 arch/x86/kernel/signal.c:674
 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: 0033:0x7f82c8df7d27
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:00007f82c80700e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f82c8fe7fa8 RCX: 00007f82c8df7d29
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f82c8fe7fa8
RBP: 00007f82c8fe7fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f82c8fe7fac
R13: 0000000000000000 R14: 00007ffe7182dcd0 R15: 00007ffe7182ddb8
 </TASK>
sched: RT throttling activated