rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=45f/1/0x4000000000000002 softirq=10168/10168 fqs=0 (detected by 1, t=10505 jiffies, g=12417, q=490) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5078 Comm: syz.0.29 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202 Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 90 cd f1 0b 48 89 de 5b e9 47 9e 43 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d 64 a5 8a 7e 65 8b 15 65 a5 8a 7e 81 e2 00 RSP: 0018:ffffc9000300f320 EFLAGS: 00000097 RAX: ffffffff817deaab RBX: 0000000000000000 RCX: ffff88802a148000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00004000000003c0 CR3: 000000007de20000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: cpu_max_bits_warn include/linux/cpumask.h:108 [inline] cpumask_check include/linux/cpumask.h:115 [inline] cpumask_test_cpu include/linux/cpumask.h:344 [inline] cpu_online include/linux/cpumask.h:895 [inline] trace_irq_disable include/trace/events/preemptirq.h:36 [inline] trace_hardirqs_off_finish+0x85/0x1f0 kernel/trace/trace_preemptirq.c:67 irqentry_enter+0x33/0x50 kernel/entry/common.c:384 sysvec_irq_work+0xa/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674 Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ad 13 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b RSP: 0018:ffffc9000300f420 EFLAGS: 00000206 RAX: 02dd9152ca45d800 RBX: 1ffff92000601e88 RCX: 02dd9152ca45d800 RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a4c0 RBP: ffffc9000300f4f0 R08: dffffc0000000000 R09: fffffbfff1ff7a19 R10: fffffbfff1ff7a19 R11: 1ffffffff1ff7a18 R12: ffffffff8c120b00 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:771 [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+0xfbc/0x2520 mm/memory.c:1576 unmap_vmas+0x11b/0x230 mm/memory.c:1653 exit_mmap+0x38f/0x5f0 mm/mmap.c:3216 __mmput+0x115/0x3b0 kernel/fork.c:1127 exit_mm+0x567/0x6c0 kernel/exit.c:550 do_exit+0x5a1/0x20a0 kernel/exit.c:870 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xc1/0x1300 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: 0033:0x7f51eb147de9 Code: Unable to access opcode bytes at RIP 0x7f51eb147dbf. RSP: 002b:00007f51ea3b90e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f51eb360fa8 RCX: 00007f51eb147de9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f51eb360fa8 RBP: 00007f51eb360fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f51eb360fac R13: 0000000000000000 R14: 00007ffe5b05a870 R15: 00007ffe5b05a958 rcu: rcu_preempt kthread timer wakeup didn't happen for 10504 jiffies! g12417 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=6914 rcu: rcu_preempt kthread starved for 10505 jiffies! g12417 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:27848 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 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: 5078 Comm: syz.0.29 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:perf_tp_event_match kernel/events/core.c:9995 [inline] RIP: 0010:perf_tp_event+0x21a/0xb50 kernel/events/core.c:10046 Code: d8 01 00 00 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 0f 85 d2 01 00 00 45 8b 3f 44 89 fe 83 e6 01 <31> ff e8 1f ec e0 ff 41 83 e7 01 75 44 4d 8d bd 00 01 00 00 4c 89 RSP: 0018:ffffc9000300ef40 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 1ffff11017206a35 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002 RBP: ffffc9000300f1c8 R08: dffffc0000000000 R09: fffffbfff1ad32b6 R10: fffffbfff1ad32b6 R11: 1ffffffff1ad32b5 R12: ffff8880b90351a8 R13: ffff888073ec23d0 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00004000000003c0 CR3: 000000007de20000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 perf_trace_preemptirq_template+0x2be/0x380 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+0x84/0x480 kernel/rcu/tree_plugin.h:674 Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ad 13 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b RSP: 0018:ffffc9000300f420 EFLAGS: 00000206 RAX: 02dd9152ca45d800 RBX: 1ffff92000601e88 RCX: 02dd9152ca45d800 RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a4c0 RBP: ffffc9000300f4f0 R08: dffffc0000000000 R09: fffffbfff1ff7a19 R10: fffffbfff1ff7a19 R11: 1ffffffff1ff7a18 R12: ffffffff8c120b00 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:771 [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+0xfbc/0x2520 mm/memory.c:1576 unmap_vmas+0x11b/0x230 mm/memory.c:1653 exit_mmap+0x38f/0x5f0 mm/mmap.c:3216 __mmput+0x115/0x3b0 kernel/fork.c:1127 exit_mm+0x567/0x6c0 kernel/exit.c:550 do_exit+0x5a1/0x20a0 kernel/exit.c:870 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xc1/0x1300 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: 0033:0x7f51eb147de9 Code: Unable to access opcode bytes at RIP 0x7f51eb147dbf. RSP: 002b:00007f51ea3b90e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f51eb360fa8 RCX: 00007f51eb147de9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f51eb360fa8 RBP: 00007f51eb360fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f51eb360fac R13: 0000000000000000 R14: 00007ffe5b05a870 R15: 00007ffe5b05a958