rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-....: (1 GPs behind) idle=b31/1/0x4000000000000002 softirq=7498/7499 fqs=2100 (detected by 1, t=10506 jiffies, g=9493, q=457) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4429 Comm: syz.0.39 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:hlock_class kernel/locking/lockdep.c:-1 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4711 [inline] RIP: 0010:__lock_acquire+0x947/0x7d10 kernel/locking/lockdep.c:4962 Code: 00 00 00 e8 fb 35 61 00 4c 0f a3 35 43 40 c0 0e 73 1a 4b 8d 04 76 c1 e0 06 4c 8d b0 80 df b5 8f 49 b8 00 00 00 00 00 fc ff df 2b 49 b8 00 00 00 00 00 fc ff df 48 8b 84 24 90 00 00 00 42 0f RSP: 0018:ffffc9000332e8a0 EFLAGS: 00000006 RAX: 0000000000000fc0 RBX: 0000000000000001 RCX: ffffffff815d2075 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901d60c0 RBP: ffffc9000332eaf0 R08: dffffc0000000000 R09: 1ffffffff203ac18 R10: dffffc0000000000 R11: fffffbfff203ac19 R12: ffff888023608b38 R13: 0000000000000002 R14: ffffffff8fb5ef40 R15: ffff888023608b38 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faab7a45ff8 CR3: 000000000c08e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313 rcu_read_lock include/linux/rcupdate.h:740 [inline] __perf_output_begin kernel/events/ring_buffer.c:163 [inline] perf_output_begin_forward+0xa5/0xa40 kernel/events/ring_buffer.c:271 __perf_event_output kernel/events/core.c:7804 [inline] perf_event_output_forward+0x19b/0x2e0 kernel/events/core.c:7822 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515 perf_swevent_overflow kernel/events/core.c:9591 [inline] perf_swevent_event+0x4ad/0x530 kernel/events/core.c:9629 perf_tp_event+0x383/0xbf0 kernel/events/core.c:10047 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674 Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 d2 df 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc9000332f420 EFLAGS: 00000206 RAX: f5013b4174682100 RBX: 1ffff92000665e88 RCX: f5013b4174682100 RDX: dffffc0000000000 RSI: ffffffff8a2b3100 RDI: ffffffff8a7a0700 RBP: ffffc9000332f4f0 R08: ffffffff901d60c7 R09: 1ffffffff203ac18 R10: dffffc0000000000 R11: fffffbfff203ac19 R12: ffffffff8c323800 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] __unlock_page_memcg+0xea/0x100 mm/memcontrol.c:2093 zap_pte_range mm/memory.c:1384 [inline] zap_pmd_range mm/memory.c:1505 [inline] zap_pud_range mm/memory.c:1534 [inline] zap_p4d_range mm/memory.c:1555 [inline] unmap_page_range+0xf96/0x2500 mm/memory.c:1576 unmap_vmas+0x131/0x250 mm/memory.c:1653 exit_mmap+0x3b9/0x640 mm/mmap.c:3216 __mmput+0x115/0x3b0 kernel/fork.c:1127 exit_mm+0x5f7/0x770 kernel/exit.c:551 do_exit+0x5a9/0x20c0 kernel/exit.c:871 do_group_exit+0x12e/0x300 kernel/exit.c:998 get_signal+0x6d6/0x12d0 kernel/signal.c:2900 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7faab83e4e59 Code: Unable to access opcode bytes at RIP 0x7faab83e4e2f. RSP: 002b:00007faab7a460e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007faab865dfa8 RCX: 00007faab83e4e59 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007faab865dfac RBP: 00007faab865dfa0 R08: 0035239ade2b81d0 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007faab865e038 R14: 00007ffe361772d0 R15: 00007ffe361773b8