syz_tun: tun_net_xmit 86 syz_tun: tun_net_xmit 86 syz_tun: tun_net_xmit 86 syz_tun: tun_net_xmit 86 rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5823/1:b..l rcu: (detected by 0, t=10503 jiffies, g=57145, q=1010615 ncpus=2) task:syz-executor state:R running task stack:20520 pid:5823 tgid:5823 ppid:5822 task_flags:0x400100 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:unwind_next_frame+0x676/0x2390 arch/x86/kernel/unwind_orc.c:517 Code: 48 8b 44 24 58 80 3c 28 00 74 11 4c 89 ff e8 c1 39 b1 00 48 8b 34 24 48 8b 54 24 08 4d 8b 27 48 8d 5a 01 48 89 d0 48 c1 e8 03 <0f> b6 04 28 84 c0 0f 85 45 19 00 00 48 89 d8 48 c1 e8 03 0f b6 04 RSP: 0018:ffffc9000409f5f8 EFLAGS: 00000a02 RAX: 1ffffffff207eefe RBX: ffffffff903f77f3 RCX: ffffffff8fbefad0 RDX: ffffffff903f77f2 RSI: ffffffff903f77f6 RDI: ffffffff8be28b20 RBP: dffffc0000000000 R08: 000000000000000b R09: ffffffff81729af5 R10: ffffc9000409f718 R11: ffffffff81acf690 R12: ffffc9000409fc60 R13: ffffc9000409f718 R14: ffffc9000409f6c8 R15: ffffc9000409f700 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x161/0x1c0 mm/slub.c:3186 put_cpu_partial+0x17c/0x250 mm/slub.c:3261 __slab_free+0x2f7/0x400 mm/slub.c:4513 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_lru_noprof+0x1c6/0x3d0 mm/slub.c:4216 __d_alloc+0x31/0x6f0 fs/dcache.c:1690 d_alloc_pseudo+0x1f/0xb0 fs/dcache.c:1821 alloc_path_pseudo fs/file_table.c:360 [inline] alloc_file_pseudo+0xcc/0x210 fs/file_table.c:376 create_pipe_files+0x32b/0x760 fs/pipe.c:942 __do_pipe_flags+0x4c/0x2d0 fs/pipe.c:983 do_pipe2+0x9c/0x170 fs/pipe.c:1034 __do_sys_pipe2 fs/pipe.c:1052 [inline] __se_sys_pipe2 fs/pipe.c:1050 [inline] __x64_sys_pipe2+0x5a/0x70 fs/pipe.c:1050 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faa3cf8d649 RSP: 002b:00007ffc3ea59458 EFLAGS: 00000246 ORIG_RAX: 0000000000000125 RAX: ffffffffffffffda RBX: 00005555740cfc70 RCX: 00007faa3cf8d649 RDX: 0000000000000008 RSI: 0000000000000000 RDI: 00007ffc3ea59468 RBP: 00007ffc3ea59820 R08: 0000000000000007 R09: 00005555740d9790 R10: 9976b0a129a352e9 R11: 0000000000000246 R12: 00005555740cca80 R13: 00005555740d1468 R14: 00007ffc3ea595a0 R15: 00005555740cf018 rcu: rcu_preempt kthread starved for 10049 jiffies! g57145 f0x2 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:27320 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-rc2-syzkaller-00087-g24770983ccfe #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 23 d6 21 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c6 RAX: b34058681a94e500 RBX: ffffffff81975d58 RCX: b34058681a94e500 RDX: 0000000000000001 RSI: ffffffff8d9823c9 RDI: ffffffff8be28b80 RBP: ffffffff8de07ea8 R08: ffff8880b8632f5b R09: 1ffff110170c65eb R10: dffffc0000000000 R11: ffffed10170c65ec R12: ffffffff8fa10df0 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a50 FS: 0000000000000000(0000) GS:ffff888125c51000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055556cb75350 CR3: 0000000075a78000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423 rest_init+0x2de/0x300 init/main.c:745 start_kernel+0x47d/0x500 init/main.c:1102 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147 syz_tun: tun_net_xmit 86 syz_tun: tun_net_xmit 86