rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=901/1/0x4000000000000002 softirq=51138/51138 fqs=0 (detected by 1, t=10505 jiffies, g=67237, q=3297) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 19311 Comm: syz.0.3950 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__irq_work_queue_local+0x5/0x190 kernel/irq_work.c:54 Code: 00 00 00 e8 cd 1f f4 ff 45 84 e4 74 cf e8 63 1d f4 ff 44 89 fd e9 3d ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 55 41 57 41 56 <41> 54 53 48 89 fb 49 bf 00 00 00 00 00 fc ff df e8 36 1d f4 ff 4c RSP: 0018:ffffc900014fef88 EFLAGS: 00000093 RAX: ffffffff81851b66 RBX: ffff8880b903b1f0 RCX: ffff888077123b80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880b903b1f0 RBP: 0000000000000000 R08: ffff8880b903b1fb R09: 1ffff1101720763f R10: dffffc0000000000 R11: ffffed1017207640 R12: 0000000000000000 R13: dffffc0000000001 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000003ff6 CR3: 000000000c08e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: irq_work_queue_on+0x11e/0x220 kernel/irq_work.c:109 rcu_read_unlock_special+0x37b/0x4a0 kernel/rcu/tree_plugin.h:667 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] BPF_PROG_RUN_ARRAY include/linux/bpf.h:1444 [inline] trace_call_bpf+0x4f9/0x5b0 kernel/trace/bpf_trace.c:127 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10016 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:ffffc900014ff420 EFLAGS: 00000206 RAX: a07ddb56b00f6900 RBX: 1ffff9200029fe88 RCX: a07ddb56b00f6900 RDX: dffffc0000000000 RSI: ffffffff8a2b3100 RDI: ffffffff8a7a0700 RBP: ffffc900014ff4f0 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: 0033:0x7eff28477e59 Code: Unable to access opcode bytes at RIP 0x7eff28477e2f. RSP: 002b:00007eff266b0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: fffffffffffffffc RBX: 00007eff286f1090 RCX: 00007eff28477e59 RDX: 0000000000000050 RSI: 0000200000000180 RDI: 000000000000000a RBP: 00007eff2850dd6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007eff286f1128 R14: 00007eff286f1090 R15: 00007fff6fa65d08 rcu: rcu_preempt kthread timer wakeup didn't happen for 10504 jiffies! g67237 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=46910 rcu: rcu_preempt kthread starved for 10505 jiffies! g67237 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 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:27600 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 19311 Comm: syz.0.3950 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:127 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:134 [inline] RIP: 0010:rcu_irq_enter_irqson+0xbf/0x120 kernel/rcu/tree.c:1088 Code: c7 84 1a 00 e8 42 03 58 08 e8 cd 80 1a 00 48 b8 04 00 00 00 00 fc ff df c6 04 03 00 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 44 24 20 00 02 00 00 c6 04 03 f8 75 3e 41 f7 c7 00 02 00 00 74 RSP: 0018:ffffc900014ff280 EFLAGS: 00000002 RAX: dffffc0000000004 RBX: 1ffff9200029fe50 RCX: ffffffff89bce3dd RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880b903b308 RBP: ffffc900014ff328 R08: ffff8880b903b30b R09: 1ffff11017207661 R10: dffffc0000000000 R11: ffffed1017207662 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000806 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000003ff6 CR3: 000000000c08e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: trace_irq_enable_rcuidle+0xc6/0x180 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:ffffc900014ff420 EFLAGS: 00000206 RAX: a07ddb56b00f6900 RBX: 1ffff9200029fe88 RCX: a07ddb56b00f6900 RDX: dffffc0000000000 RSI: ffffffff8a2b3100 RDI: ffffffff8a7a0700 RBP: ffffc900014ff4f0 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: 0033:0x7eff28477e59 Code: Unable to access opcode bytes at RIP 0x7eff28477e2f. RSP: 002b:00007eff266b0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: fffffffffffffffc RBX: 00007eff286f1090 RCX: 00007eff28477e59 RDX: 0000000000000050 RSI: 0000200000000180 RDI: 000000000000000a RBP: 00007eff2850dd6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007eff286f1128 R14: 00007eff286f1090 R15: 00007fff6fa65d08