rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=97b4/1/0x4000000000000000 softirq=98598/98598 fqs=0
rcu: 	(detected by 1, t=10502 jiffies, g=146649, q=240 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 23692 Comm: syz.1.4899 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:80 [inline]
RIP: 0010:rcu_is_watching+0x6/0xb0 kernel/rcu/tree.c:699
Code: 8a e8 8e 20 13 09 48 c7 c7 00 86 13 8d 4c 89 f6 e8 df db eb 02 e9 44 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 41 57 <41> 56 53 65 ff 05 68 01 93 7e e8 4b 36 13 09 89 c3 83 f8 08 73 60
RSP: 0018:ffffc90000007a30 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81688636
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e8ae5e8
RBP: ffffc90000007b50 R08: ffffffff8e8ae5ef R09: 1ffffffff1d15cbd
R10: dffffc0000000000 R11: fffffbfff1d15cbe R12: ffffffff8430558b
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff92000000f54
FS:  00007f98c12986c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f98c03eb540 CR3: 00000000651ec000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000001800
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 trace_lock_release include/trace/events/lock.h:69 [inline]
 lock_release+0xb5/0x8c0 kernel/locking/lockdep.c:5765
 debug_objects_fill_pool+0xcc/0x790 lib/debugobjects.c:617
 debug_object_activate+0x36/0x500 lib/debugobjects.c:705
 debug_hrtimer_activate kernel/time/hrtimer.c:450 [inline]
 debug_activate kernel/time/hrtimer.c:504 [inline]
 enqueue_hrtimer+0x34/0x380 kernel/time/hrtimer.c:1100
 __run_hrtimer kernel/time/hrtimer.c:1771 [inline]
 __hrtimer_run_queues+0x62f/0xc10 kernel/time/hrtimer.c:1818
 hrtimer_interrupt+0x39d/0x980 kernel/time/hrtimer.c:1880
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194
Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 4b e4 ce f6 65 8b 05 1c 33 76 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc900043a75a0 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: 2e3fdae2c6e75000
RDX: dffffc0000000000 RSI: ffffffff8acacb60 RDI: 0000000000000001
RBP: ffffc900043a7638 R08: ffffffff911bc5af R09: 1ffffffff22378b5
R10: dffffc0000000000 R11: fffffbfff22378b6 R12: dffffc0000000000
R13: ffff8880789bd9d0 R14: ffff8880789bd9d0 R15: 1ffff92000874eb4
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __skb_try_recv_datagram+0x181/0x4e0 net/core/datagram.c:265
 __unix_dgram_recvmsg+0x2f9/0xd90 net/unix/af_unix.c:2412
 sock_recvmsg_nosec+0x82/0xd0 net/socket.c:1047
 ____sys_recvmsg+0x4d7/0x5d0 net/socket.c:2812
 ___sys_recvmsg+0x214/0x590 net/socket.c:2856
 do_recvmmsg+0x377/0x810 net/socket.c:2950
 __sys_recvmmsg net/socket.c:3029 [inline]
 __do_sys_recvmmsg net/socket.c:3052 [inline]
 __se_sys_recvmmsg net/socket.c:3045 [inline]
 __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3045
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f98c039de59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f98c1298028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f98c0626090 RCX: 00007f98c039de59
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007f98c0433e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f98c0626128 R14: 00007f98c0626090 R15: 00007ffd021ee8b8
 </TASK>
rcu: rcu_preempt kthread starved for 10502 jiffies! g146649 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:27384 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x9d/0x3b0 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: 1 PID: 23696 Comm: syz.2.4900 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline]
RIP: 0010:smp_call_function_many_cond+0xd85/0x1190 kernel/smp.c:855
Code: 45 8b 34 24 44 89 f6 83 e6 01 31 ff e8 34 f1 0a 00 41 83 e6 01 49 be 00 00 00 00 00 fc ff df 75 07 e8 6f ed 0a 00 eb 38 f3 90 <42> 0f b6 04 33 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 53 ed
RSP: 0018:ffffc9000440fa80 EFLAGS: 00000246
RAX: ffffffff817bf7fd RBX: 1ffff110171c87a9 RCX: 0000000000080000
RDX: ffffc9000d5bb000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000440fbf0 R08: ffffffff8e8ae5ef R09: 1ffffffff1d15cbd
R10: dffffc0000000000 R11: fffffbfff1d15cbe R12: ffff8880b8e43d48
R13: ffff8880b8f3d3c0 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007f3650abd6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2dd20ff8 CR3: 000000002f067000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 clock_was_set+0x756/0x800 kernel/time/hrtimer.c:990
 do_settimeofday64+0x59b/0x750 kernel/time/timekeeping.c:1345
 __do_sys_clock_settime kernel/time/posix-timers.c:1130 [inline]
 __se_sys_clock_settime kernel/time/posix-timers.c:1114 [inline]
 __x64_sys_clock_settime+0x25e/0x2a0 kernel/time/posix-timers.c:1114
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f364fb9de59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3650abd028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007f364fe25fa0 RCX: 00007f364fb9de59
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000
RBP: 00007f364fc33e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f364fe26038 R14: 00007f364fe25fa0 R15: 00007ffd3d4a3f88
 </TASK>