rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=47581, q=321 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295004785-4294994283), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g47581 f0x2 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:27576 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 10086 Comm: syz.1.1712 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__lock_acquire+0x14c/0x7d80 kernel/locking/lockdep.c:5009
Code: f3 d5 90 75 03 45 31 ff 44 89 6c 24 50 4c 89 74 24 28 83 fb 01 77 2f 89 d8 4c 8d 74 c7 08 4c 89 f0 48 c1 e8 03 42 80 3c 00 00 <74> 12 4c 89 f7 e8 0a 64 77 00 49 b8 00 00 00 00 00 fc ff df 4d 8b
RSP: 0018:ffffc900001f0100 EFLAGS: 00000046
RAX: 1ffffffff1a2972a RBX: 0000000000000000 RCX: 1ffff9200003e044
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8d14b948
RBP: ffffc900001f0348 R08: dffffc0000000000 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff1d190ce R12: 0000000000000001
R13: 0000000000000002 R14: ffffffff8d14b950 R15: 0000000000000001
FS:  00007fa4715c26c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000b0000 CR3: 000000003a3b2000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 seqcount_lockdep_reader_access+0xd1/0x1d0 include/linux/seqlock.h:102
 timekeeping_get_delta kernel/time/timekeeping.c:254 [inline]
 timekeeping_get_ns kernel/time/timekeeping.c:388 [inline]
 ktime_get_update_offsets_now+0x99/0x3f0 kernel/time/timekeeping.c:2320
 hrtimer_update_base kernel/time/hrtimer.c:654 [inline]
 hrtimer_interrupt+0x11e/0x980 kernel/time/hrtimer.c:1862
 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+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x30 kernel/rcu/update.c:318
Code: 2a fd 03 00 75 e8 48 c7 c7 80 ca ca 8a 48 c7 c6 a0 ee ca 8a e8 c1 ae c1 f6 0f 0b eb d1 cc cc cc cc cc cc cc cc cc cc cc cc cc <f3> 0f 1e fa 31 c0 83 3d 1f f7 fc 03 00 74 1d 83 3d 96 2a fd 03 00
RSP: 0018:ffffc900001f07b0 EFLAGS: 00000246
RAX: 1ffff11027fff226 RBX: ffffffff81eade42 RCX: ffff88802d443c00
RDX: 0000000000000100 RSI: 000000000004b4b8 RDI: 00000003ffffffff
RBP: 0000000000000001 R08: dffffc0000000000 R09: 1ffffffff223dea0
R10: dffffc0000000000 R11: fffffbfff223dea1 R12: dffffc0000000000
R13: 0000000000000120 R14: 000000000004b4b8 R15: ffff888018fc0000
 rcu_read_lock_held_common kernel/rcu/update.c:104 [inline]
 rcu_read_lock_held+0xa/0x40 kernel/rcu/update.c:348
 lookup_page_ext mm/page_ext.c:240 [inline]
 page_ext_get+0x193/0x2b0 mm/page_ext.c:509
 __reset_page_owner+0x2e/0x190 mm/page_owner.c:145
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1182 [inline]
 free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2459
 napi_frag_unref include/linux/skbuff.h:3539 [inline]
 skb_release_data+0x3ca/0x7f0 net/core/skbuff.c:982
 skb_release_all net/core/skbuff.c:1054 [inline]
 __kfree_skb+0x57/0x70 net/core/skbuff.c:1068
 tcp_write_queue_purge+0x140/0x310 net/ipv4/tcp.c:3007
 tcp_done_with_error+0x43/0xc0 net/ipv4/tcp_input.c:4476
 tcp_write_err net/ipv4/tcp_timer.c:72 [inline]
 tcp_write_timeout net/ipv4/tcp_timer.c:281 [inline]
 tcp_retransmit_timer+0x1c94/0x3030 net/ipv4/tcp_timer.c:576
 tcp_write_timer+0x12a/0x280 net/ipv4/tcp_timer.c:709
 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x570/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x27d/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 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:finish_task_switch+0x267/0x8f0 kernel/sched/core.c:5256
Code: 31 09 85 c0 0f 84 30 01 00 00 48 85 db 0f 85 4f 01 00 00 0f 1f 44 00 00 4c 89 e7 e8 73 77 3b 09 e8 0e 1a 30 00 fb 4c 8b 65 b8 <49> 8d bc 24 00 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc90019e2f160 EFLAGS: 00000286
RAX: b8fb736205009500 RBX: 0000000000000000 RCX: b8fb736205009500
RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: ffffffff8b1d3260
RBP: ffffc90019e2f1b0 R08: ffffffff911ef52f R09: 1ffffffff223dea5
R10: dffffc0000000000 R11: fffffbfff223dea6 R12: ffff88802d443c00
R13: 1ffff110171e79a9 R14: dffffc0000000000 R15: ffff8880b8f3cd48
 context_switch kernel/sched/core.c:5385 [inline]
 __schedule+0x15b6/0x4660 kernel/sched/core.c:6701
 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7011
 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:virt_to_folio include/linux/mm.h:-1 [inline]
RIP: 0010:virt_to_slab mm/slab.h:218 [inline]
RIP: 0010:___cache_free+0x3a/0x150 mm/slub.c:3837
Code: 89 ff 48 89 f7 e8 86 f2 5d ff 48 c1 e8 06 48 83 e0 c0 48 ba 00 00 00 00 00 ea ff ff 48 8b 4c 10 08 f6 c1 01 0f 85 e7 00 00 00 <48> 01 d0 0f 1f 44 00 00 48 8b 48 08 f6 c1 01 0f 85 e7 00 00 00 66
RSP: 0018:ffffc90019e2f540 EFLAGS: 00000246
RAX: 00000000011e9c40 RBX: ffff888047a71500 RCX: ffff88801da67640
RDX: ffffea0000000000 RSI: ffff888047a71500 RDI: ffff888047a71500
RBP: ffff888048bd6000 R08: 0000000000000001 R09: 0000000000000000
R10: ffff888048bd2000 R11: ffffed10171e8429 R12: ffff88801da67640
R13: dffffc0000000000 R14: ffffffff81dffefa R15: ffff88801da67640
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6a/0x4d0 mm/slab.h:770
 slab_alloc_node mm/slub.c:3495 [inline]
 kmem_cache_alloc_node+0x1af/0x310 mm/slub.c:3540
 __alloc_skb+0x103/0x2c0 net/core/skbuff.c:643
 alloc_skb_fclone include/linux/skbuff.h:1366 [inline]
 tcp_stream_alloc_skb+0x3d/0x330 net/ipv4/tcp.c:876
 tcp_sendmsg_locked+0xcf0/0x4ab0 net/ipv4/tcp.c:1158
 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1348
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x61b/0x980 net/socket.c:2595
 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2649
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2687 [inline]
 __se_sys_sendmsg+0x1d0/0x2c0 net/socket.c:2685
 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: 0033:0x7fa47079e0d9
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:00007fa4715c2028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa470a25fa0 RCX: 00007fa47079e0d9
RDX: 00000000000052cc RSI: 0000200000000040 RDI: 0000000000000007
RBP: 00007fa470835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa470a26038 R14: 00007fa470a25fa0 R15: 00007ffd17a0d638
 </TASK>