rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (9970 ticks this GP) idle=1054/1/0x4000000000000000 softirq=21725/21725 fqs=5195 rcu: hardirqs softirqs csw/system rcu: number: 1210611 0 0 rcu: cputime: 17251 35238 67 ==> 52500(ms) rcu: (t=10501 jiffies g=24541 q=3876 ncpus=2) CPU: 0 PID: 7749 Comm: syz.1.562 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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 2b 88 ca f6 65 8b 05 bc b0 71 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc90000007740 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: 90b86998aaf72f00 RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: 0000000000000001 RBP: ffffc900000077c0 R08: ffffffff911cd5c7 R09: 1ffffffff2239ab8 R10: dffffc0000000000 R11: fffffbfff2239ab9 R12: dffffc0000000000 R13: ffff88805e230000 R14: ffffffff97496468 R15: 1ffff92000000ee8 FS: 00007fe1d24a46c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2de23ffc CR3: 000000002ce18000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __debug_check_no_obj_freed lib/debugobjects.c:999 [inline] debug_check_no_obj_freed+0x51f/0x540 lib/debugobjects.c:1020 free_pages_prepare mm/page_alloc.c:1187 [inline] free_unref_page_prepare+0x1da/0x8c0 mm/page_alloc.c:2365 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458 napi_frag_unref include/linux/skbuff.h:3539 [inline] skb_release_data+0x3a9/0x7b0 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+0x143/0x2f0 net/ipv4/tcp.c:3007 tcp_done_with_error+0x43/0xc0 net/ipv4/tcp_input.c:4446 tcp_write_err net/ipv4/tcp_timer.c:72 [inline] tcp_write_timeout net/ipv4/tcp_timer.c:281 [inline] tcp_retransmit_timer+0x1728/0x3020 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+0x542/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 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 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:generic_exec_single+0x481/0x4f0 kernel/smp.c:418 Code: 75 11 e8 c2 06 0b 00 48 85 db 75 16 e8 b8 06 0b 00 eb 15 e8 b1 06 0b 00 e8 9c 36 0c 09 48 85 db 74 ea e8 a2 06 0b 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 43 c7 44 2c 08 RSP: 0018:ffffc90005287a00 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000080000 RDX: ffffc9000d10b000 RSI: 00000000000042db RDI: 00000000000042dc RBP: ffffc90005287ad0 R08: ffffffff911cd5ff R09: 1ffffffff2239abf R10: dffffc0000000000 R11: fffffbfff2239ac0 R12: 1ffff92000a50f44 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff92000a50f65 smp_call_function_single+0x36d/0x5a0 kernel/smp.c:647 task_function_call kernel/events/core.c:120 [inline] perf_install_in_context+0x5be/0x920 kernel/events/core.c:2959 __do_sys_perf_event_open kernel/events/core.c:12957 [inline] __se_sys_perf_event_open+0x1836/0x1c50 kernel/events/core.c:12609 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: 0033:0x7fe1d159ce59 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:00007fe1d24a4028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007fe1d1815fa0 RCX: 00007fe1d159ce59 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140 RBP: 00007fe1d1632d6f R08: 0000000000000002 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe1d1816038 R14: 00007fe1d1815fa0 R15: 00007ffc22e953a8