rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P31299/5:b..l rcu: (detected by 1, t=10505 jiffies, g=103469, q=274 ncpus=2) task:syz-executor state:R running task stack:16536 pid:31299 tgid:31299 ppid:31291 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6863 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:page_table_check_set+0x2b4/0x610 mm/page_table_check.c:120 Code: be 04 00 00 00 e8 dc 1d f9 ff 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 0f 85 51 01 00 00 44 8b 3b <31> ff 44 89 fe e8 42 b9 96 ff 45 85 ff 0f 85 4e 02 00 00 48 8d 7b RSP: 0018:ffffc900042873c8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff88801d8209d8 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88801d8209d8 RBP: ffff88801d820990 R08: ffff88801d8209db R09: 1ffff11003b0413b R10: dffffc0000000000 R11: ffffed1003b0413c R12: 0000000000000001 R13: 0000000000088685 R14: 0000000000000001 R15: 0000000000000000 page_table_check_ptes_set include/linux/page_table_check.h:76 [inline] set_ptes include/linux/pgtable.h:292 [inline] __copy_present_ptes mm/memory.c:1102 [inline] copy_present_ptes mm/memory.c:1181 [inline] copy_pte_range mm/memory.c:1304 [inline] copy_pmd_range+0x49e2/0x7980 mm/memory.c:1392 copy_pud_range mm/memory.c:1429 [inline] copy_p4d_range mm/memory.c:1453 [inline] copy_page_range+0xae6/0x1130 mm/memory.c:1535 dup_mmap+0xf56/0x1b40 mm/mmap.c:1827 dup_mm kernel/fork.c:1529 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1581 copy_process+0x1665/0x3960 kernel/fork.c:2221 kernel_clone+0x21d/0x7a0 kernel/fork.c:2651 __do_sys_clone kernel/fork.c:2792 [inline] __se_sys_clone kernel/fork.c:2776 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2776 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9f62b85e93 RSP: 002b:00007ffe5294edf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9f62b85e93 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055556103e7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 000000000013024c R15: 00007ffe5294ef90 rcu: rcu_preempt kthread starved for 10503 jiffies! g103469 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:26136 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5919 Comm: kworker/0:6 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: 0x0 (events_long) RIP: 0010:num_possible_cpus include/linux/cpumask.h:1222 [inline] RIP: 0010:mm_get_cid+0xb1/0x130 kernel/sched/sched.h:3759 Code: 41 5f 5d e9 d1 ff 43 09 cc 49 c7 c5 c8 f4 00 8d 49 c1 ed 03 bd 00 00 00 80 eb 07 44 89 f0 f7 d8 71 d4 f3 90 43 0f b6 44 25 00 <84> c0 75 41 44 8b 3d 0c 7d 6e 0b 48 89 df 4c 89 fe e8 49 53 ea 02 RSP: 0018:ffffc900050ef9a8 EFLAGS: 00000887 RAX: 0000000000000000 RBX: ffff8880295d18d0 RCX: 1ffff1100b80ae0c RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff8880295d18d0 RBP: 0000000080000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed10052ba2eb R12: dffffc0000000000 R13: 1ffffffff1a01e99 R14: 0000000080000000 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff888126d12000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000000 CR3: 0000000048958000 CR4: 00000000003526f0 Call Trace: mm_cid_from_cpu kernel/sched/sched.h:3820 [inline] mm_cid_schedin kernel/sched/sched.h:3870 [inline] mm_cid_switch_to kernel/sched/sched.h:3886 [inline] context_switch kernel/sched/core.c:5245 [inline] __schedule+0x2153/0x50a0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 worker_thread+0xa82/0xda0 kernel/workqueue.c:3436 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 watchdog: BUG: soft lockup - CPU#1 stuck for 235s! [syz-executor:5811] Modules linked in: irq event stamp: 13000446 hardirqs last enabled at (13000445): [] irqentry_exit+0x5dd/0x660 kernel/entry/common.c:219 hardirqs last disabled at (13000446): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056 softirqs last enabled at (12948192): [] __local_bh_enable_ip+0x1b3/0x2e0 kernel/softirq.c:305 softirqs last disabled at (12948186): [] local_bh_disable include/linux/bottom_half.h:20 [inline] softirqs last disabled at (12948186): [] spin_lock_bh include/linux/spinlock_rt.h:87 [inline] softirqs last disabled at (12948186): [] release_sock+0x2f/0x210 net/core/sock.c:3793 CPU: 1 UID: 0 PID: 5811 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xec6/0x12b0 kernel/smp.c:877 Code: 89 ee 83 e6 01 31 ff e8 c8 9d 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 03 99 0b 00 eb 38 f3 90 42 0f b6 04 2b <84> c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 e7 98 0b 00 eb e4 44 RSP: 0018:ffffc90004987580 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff11017108b21 RCX: ffff88803439bc80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90004987700 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1db516f R12: ffff8880b8845908 R13: dffffc0000000000 R14: ffff8880b893c8c0 R15: 0000000000000000 FS: 000055556b43d500(0000) GS:ffff888126e12000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbb7d00dd58 CR3: 0000000033004000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline] flush_tlb_mm_range+0x6b1/0x1280 arch/x86/mm/tlb.c:1472 dup_mmap+0x1618/0x1b40 mm/mmap.c:1866 dup_mm kernel/fork.c:1529 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1581 copy_process+0x1665/0x3960 kernel/fork.c:2221 kernel_clone+0x21d/0x7a0 kernel/fork.c:2651 __do_sys_clone kernel/fork.c:2792 [inline] __se_sys_clone kernel/fork.c:2776 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2776 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa1e8bd5e93 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007fff27d67058 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa1e8bd5e93 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055556b43d7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000130488 R15: 00007fff27d671f0 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5919 Comm: kworker/0:6 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: 0x0 (events_long) RIP: 0010:_find_first_zero_bit+0xd/0xb0 lib/find_bit.c:149 Code: 39 0e a6 fd e9 79 ff ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 41 55 41 54 53 <48> 85 f6 74 46 48 89 f3 49 89 fe 49 bc 00 00 00 00 00 fc ff df 48 RSP: 0018:ffffc900050ef978 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff8880295d18d0 RCX: 1ffff1100b80ae0c RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff8880295d18d0 RBP: 0000000080000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed10052ba2eb R12: dffffc0000000000 R13: 1ffffffff1a01e99 R14: 0000000080000000 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff888126d12000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000000 CR3: 0000000048958000 CR4: 00000000003526f0 Call Trace: find_first_zero_bit include/linux/find.h:393 [inline] __mm_get_cid kernel/sched/sched.h:3744 [inline] mm_get_cid+0xc7/0x130 kernel/sched/sched.h:3759 mm_cid_from_cpu kernel/sched/sched.h:3820 [inline] mm_cid_schedin kernel/sched/sched.h:3870 [inline] mm_cid_switch_to kernel/sched/sched.h:3886 [inline] context_switch kernel/sched/core.c:5245 [inline] __schedule+0x2153/0x50a0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 worker_thread+0xa82/0xda0 kernel/workqueue.c:3436 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246