syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5790/1:b..l P5895/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=8913, q=735 ncpus=2)
task:syz-executor    state:R  running task     stack:21552 pid:5895  ppid:5892   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866
 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0xfa/0x110 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __wake_up_common_lock kernel/sched/wait.c:140 [inline]
 __wake_up_sync_key+0x11f/0x190 kernel/sched/wait.c:213
 sock_def_readable+0x1e1/0x430 net/core/sock.c:3346
 __netlink_sendskb net/netlink/af_netlink.c:1266 [inline]
 netlink_broadcast_deliver net/netlink/af_netlink.c:1401 [inline]
 do_one_broadcast net/netlink/af_netlink.c:1490 [inline]
 netlink_broadcast_filtered+0xd21/0x1110 net/netlink/af_netlink.c:1536
 netlink_broadcast+0x37/0x50 net/netlink/af_netlink.c:1560
 uevent_net_broadcast_untagged lib/kobject_uevent.c:331 [inline]
 kobject_uevent_net_broadcast+0x364/0x530 lib/kobject_uevent.c:409
 kobject_uevent_env+0x550/0x8c0 lib/kobject_uevent.c:608
 device_add+0x5e8/0xc20 drivers/base/core.c:3664
 device_create_groups_vargs drivers/base/core.c:4410 [inline]
 device_create+0x25c/0x2e0 drivers/base/core.c:4449
 mac80211_hwsim_new_radio+0x419/0x4cf0 drivers/net/wireless/virtual/mac80211_hwsim.c:4993
 hwsim_new_radio_nl+0xd78/0x19d0 drivers/net/wireless/virtual/mac80211_hwsim.c:5988
 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:971
 genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline]
 genl_rcv_msg+0x60b/0x790 net/netlink/genetlink.c:1066
 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1075
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x46a/0x620 net/socket.c:2201
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0xde/0xf0 net/socket.c:2209
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe7af990a3c
RSP: 002b:00007fff5a216150 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fe7b0704620 RCX: 00007fe7af990a3c
RDX: 0000000000000024 RSI: 00007fe7b0704670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007fff5a2161a4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007fe7b0704670 R15: 0000000000000000
 </TASK>
task:udevd           state:R  running task     stack:26632 pid:5790  ppid:5158   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009
 irqentry_exit+0x67/0x70 kernel/entry/common.c:438
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lock_acquire+0x1f2/0x410 kernel/locking/lockdep.c:5758
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00
RSP: 0018:ffffc90004557c00 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 99c1ff73d3c0e200
RDX: 0000000000000000 RSI: ffffffff8aaace20 RDI: ffffffff8afc72c0
RBP: ffffc90004557d08 R08: dffffc0000000000 R09: 1ffffffff21b4ea0
R10: dffffc0000000000 R11: fffffbfff21b4ea1 R12: 1ffff920008aaf8c
R13: ffffffff8cd2fe20 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 rcu_read_lock include/linux/rcupdate.h:786 [inline]
 dput+0x57/0x1e0 fs/dcache.c:904
 do_renameat2+0x8b1/0xc70 fs/namei.c:5027
 __do_sys_rename fs/namei.c:5071 [inline]
 __se_sys_rename fs/namei.c:5069 [inline]
 __x64_sys_rename+0x86/0x90 fs/namei.c:5069
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f794d07acc7
RSP: 002b:00007fffeea9b9f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 000055c3114219e0 RCX: 00007f794d07acc7
RDX: 000055c3113f7010 RSI: 00007fffeea9ba10 RDI: 00007fffeea9be10
RBP: 000055c311409b20 R08: 00000000000001e0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fffeea9ba10
R13: 00007fffeea9be10 R14: 0000000000000000 R15: 000055c2d3c849dd
 </TASK>
rcu: rcu_preempt kthread starved for 10575 jiffies! g8913 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:27752 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 5970 Comm: syz.2.19 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 00 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 2a c0 ef f6 48 89 df e8 42 92 f0 f6 e8 4d 31 14 f7 fb bf 01 00 00 00 <e8> 52 a9 e3 f6 65 8b 05 a3 f7 8b 75 85 c0 74 02 5b c3 e8 80 d9 88
RSP: 0018:ffffc900047afc98 EFLAGS: 00000282
RAX: ef74e02c62551800 RBX: ffff888030a640c0 RCX: ef74e02c62551800
RDX: dffffc0000000000 RSI: ffffffff8aaabca0 RDI: 0000000000000001
RBP: ffff888030a64558 R08: ffffffff8e4a94ef R09: 1ffffffff1c9529d
R10: dffffc0000000000 R11: fffffbfff1c9529e R12: 1ffff1100614c8ab
R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000
FS:  000055556206b500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000002bdff000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0x11f5/0x1400 kernel/signal.c:2905
 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f659b98eba9
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:00007fff80a64248 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f659bbd5fa0 RCX: 00007f659b98eba9
RDX: 000020000006b000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 00007f659ba11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f659bbd5fa0 R14: 00007f659bbd5fa0 R15: 0000000000000004
 </TASK>
sched: RT throttling activated