rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13088/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=81909, q=268 ncpus=2)
task:udevd state:R running task stack:22728 pid:13088 tgid:13088 ppid:5199 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5263 [inline]
__schedule+0x1836/0x4ed0 kernel/sched/core.c:6871
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7055
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7079
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
__wake_up_common_lock+0x190/0x1f0 kernel/sched/wait.c:127
sock_def_readable+0x1eb/0x550 net/core/sock.c:3593
unix_dgram_sendmsg+0xdfb/0x1840 net/unix/af_unix.c:2286
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:746
sock_write_iter+0x279/0x360 net/socket.c:1199
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f52566a7407
RSP: 002b:00007ffecf2b9980 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5256d45880 RCX: 00007f52566a7407
RDX: 0000000000000000 RSI: 00007ffecf2b9a27 RDI: 000000000000000a
RBP: 000000000000000a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007f5256d456e8
R13: 0000000000000000 R14: 0000000000000000 R15: 0000556f890eafa0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10491 jiffies! g81909 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=73572
rcu: rcu_preempt kthread starved for 10492 jiffies! g81909 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26904 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5263 [inline]
__schedule+0x1836/0x4ed0 kernel/sched/core.c:6871
__schedule_loop kernel/sched/core.c:6953 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6968
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 14755 Comm: syz.0.1526 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__lock_acquire+0x27a/0xd20 kernel/locking/lockdep.c:5163
Code: ff ff 44 8b 84 24 80 00 00 00 4c 8b 4c 24 70 4c 8d bf 30 0b 00 00 41 83 fd 31 48 89 74 24 20 0f 83 5e 0a 00 00 4c 89 6c 24 28 <4a> 8d 04 ad 00 00 00 00 4c 01 e8 89 f1 81 e1 ff 1f 00 00 ba 00 e0
RSP: 0018:ffffc90000a08b30 EFLAGS: 00000087
RAX: 000000000001ab0d RBX: ffff88801cf4fa80 RCX: ffffffff931f2370
RDX: 0000000000000003 RSI: 0000000000001115 RDI: ffff88802dbcdb80
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff89718d54
R10: dffffc0000000000 R11: ffffffff89718c90 R12: 0000000000000000
R13: 0000000000000003 R14: 0000000000000000 R15: ffff88802dbce6b0
FS: 00007f872e2a36c0(0000) GS:ffff888125fb9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbb93669f98 CR3: 000000002ed90000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x117/0x350 kernel/locking/lockdep.c:5868
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
advance_sched+0xc4/0xc90 net/sched/sch_taprio.c:929
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x51c/0xc70 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x410 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x16c/0x350 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 14 ff d7 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90004e2e0b8 EFLAGS: 00000206
RAX: 7a09e3dfb56a7a00 RBX: 0000000000000000 RCX: 7a09e3dfb56a7a00
RDX: 0000000000000000 RSI: ffffffff8d9761d1 RDI: ffffffff8bbf80e0
RBP: ffffffff81741ff5 R08: 0000000000000000 R09: ffffffff81741ff5
R10: ffffc90004e2e278 R11: ffffffff81ada5d0 R12: 0000000000000002
R13: ffffffff8df3d9c0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
kasan_kmalloc include/linux/kasan.h:262 [inline]
__kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5771
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
nf_nat_masq_schedule+0x30d/0x6d0 net/netfilter/nf_nat_masquerade.c:118
masq_inet6_event+0x14b/0x1b0 net/netfilter/nf_nat_masquerade.c:295
notifier_call_chain+0x19d/0x3d0 kernel/notifier.c:85
atomic_notifier_call_chain+0xda/0x180 kernel/notifier.c:223
addrconf_ifdown+0xe66/0x1890 net/ipv6/addrconf.c:3978
addrconf_notify+0x1bc/0x1080 net/ipv6/addrconf.c:-1
notifier_call_chain+0x19d/0x3d0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2269 [inline]
call_netdevice_notifiers net/core/dev.c:2283 [inline]
__dev_notify_flags+0x18d/0x2e0 net/core/dev.c:-1
netif_change_flags+0xe8/0x1a0 net/core/dev.c:9795
do_setlink+0xc55/0x41c0 net/core/rtnetlink.c:3158
rtnl_group_changelink net/core/rtnetlink.c:3790 [inline]
__rtnl_newlink net/core/rtnetlink.c:3944 [inline]
rtnl_newlink+0x14b0/0x1c90 net/core/rtnetlink.c:4072
rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:746
____sys_sendmsg+0x505/0x870 net/socket.c:2634
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2688
__sys_sendmsg net/socket.c:2720 [inline]
__do_sys_sendmsg net/socket.c:2725 [inline]
__se_sys_sendmsg net/socket.c:2723 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2723
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f872d38f749
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:00007f872e2a3038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f872d5e5fa0 RCX: 00007f872d38f749
RDX: 0000000004000c00 RSI: 0000200000000180 RDI: 0000000000000005
RBP: 00007f872d413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f872d5e6038 R14: 00007f872d5e5fa0 R15: 00007ffcf8753558