rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P17376/1:b..l rcu: (detected by 0, t=10502 jiffies, g=91241, q=406 ncpus=2) task:syz-executor state:R running task stack:23096 pid:17376 tgid:17376 ppid:17373 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x62/0x330 kernel/locking/lockdep.c:5872 Code: 36 18 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 82 83 ee 0e 0f 82 74 02 00 00 8b 35 1a b4 ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 99 36 18 12 0f 85 ad 02 00 00 48 83 c4 RSP: 0018:ffffc9000be1f870 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c9620 RCX: 0000000068c1bacb RDX: 0000000000000000 RSI: ffffffff8daa563c RDI: ffffffff8bf2a580 RBP: 0000000000000002 R08: 00000000ffffffff R09: 00000000ffffffff R10: 0000000000000002 R11: ffff88802c92d4b0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:339 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:365 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x25e/0x770 mm/slub.c:5270 alloc_empty_file+0x55/0x1e0 fs/file_table.c:237 alloc_file fs/file_table.c:354 [inline] alloc_file_pseudo+0x13a/0x230 fs/file_table.c:383 sock_alloc_file+0x50/0x210 net/socket.c:483 sock_map_fd net/socket.c:513 [inline] __sys_socket+0x1c0/0x260 net/socket.c:1756 __do_sys_socket net/socket.c:1761 [inline] __se_sys_socket net/socket.c:1759 [inline] __x64_sys_socket+0x72/0xb0 net/socket.c:1759 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff55e191667 RSP: 002b:00007ffdd8317bc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007ff55e191667 RDX: 0000000000000006 RSI: 0000000000000001 RDI: 000000000000000a RBP: 00007ffdd83182fc R08: 00000000000002d8 R09: 0079746972756365 R10: 00007ff55e3b99c0 R11: 0000000000000202 R12: 00007ff55e3b5ca0 R13: 00000000000927c0 R14: 0000000000111968 R15: 00007ff55e3b7e60 rcu: rcu_preempt kthread starved for 10489 jiffies! g91241 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:27624 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 18700 Comm: syz.7.3242 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:check_region_inline mm/kasan/generic.c:183 [inline] RIP: 0010:kasan_check_range+0x164/0x1b0 mm/kasan/generic.c:200 Code: da 4c 89 d8 4c 29 da e9 46 ff ff ff 48 85 d2 74 18 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 0a 80 38 00 74 f2 e9 75 ff ff ff 5b 01 00 00 00 5d 41 5c c3 cc cc cc cc b8 01 00 00 00 e9 95 e8 51 RSP: 0018:ffffc90000a08d08 EFLAGS: 00000046 RAX: ffffed1006d91255 RBX: ffff888035765880 RCX: ffffffff897f69da RDX: ffffed1006d91255 RSI: 0000000000000008 RDI: ffff888036c892a0 RBP: ffffed1006d91254 R08: 0000000000000000 R09: ffffed1006d91254 R10: ffff888036c892a7 R11: ffff888078aa2ff0 R12: 0000000000000000 R13: ffff888035765800 R14: 000000000401004e R15: dffffc0000000000 FS: 00007f80646a46c0(0000) GS:ffff8881249fd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f80646a3f98 CR3: 00000000421d6000 CR4: 00000000003526f0 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic64_read include/linux/atomic/atomic-instrumented.h:1610 [inline] taprio_set_budgets+0x13a/0x310 net/sched/sch_taprio.c:676 advance_sched+0x5f6/0xc80 net/sched/sch_taprio.c:983 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x202/0xc40 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3c0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:finish_task_switch.isra.0+0x210/0xbd0 kernel/sched/core.c:5114 Code: ac 08 00 00 44 8b 05 b3 91 fd 0e 45 85 c0 0f 85 be 01 00 00 4c 89 e7 e8 ae f6 ff ff e8 89 ea 3b 00 fb 65 48 8b 1d 38 14 27 12 <48> 8d bb 48 16 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc900030d75d0 EFLAGS: 00000206 RAX: 000000000000014b RBX: ffff888078aa24c0 RCX: ffffffff81c7056f RDX: 0000000000000000 RSI: ffffffff8dacb6cd RDI: ffffffff8bf2a580 RBP: ffffc900030d7618 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90887cd7 R11: ffff888078aa2ff0 R12: ffff8880b853ac80 R13: ffff88802afca4c0 R14: ffff88802afca4c0 R15: ffff8880b853bab0 context_switch kernel/sched/core.c:5259 [inline] __schedule+0x1141/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:rcu_lock_release include/linux/rcupdate.h:341 [inline] RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:897 [inline] RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1195 [inline] RIP: 0010:unwind_next_frame+0x3e6/0x20a0 arch/x86/kernel/unwind_orc.c:479 Code: c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 1d 15 00 00 41 c7 45 00 00 00 00 00 31 ed e8 d2 ad 0a 0a 85 c0 0f 85 50 06 00 00 <48> c7 c7 20 96 3c 8e 48 8d 35 00 00 00 00 e8 e7 38 2d 00 e8 42 84 RSP: 0018:ffffc900030d7898 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffc900030d7d10 RCX: ffffc900030d8001 RDX: 0000000000000000 RSI: ffffffff8bf2a500 RDI: ffffffff8dd78f28 RBP: 0000000000000001 R08: 0000000000000001 R09: 00000000ffffffff R10: 0000000000000002 R11: 0000000000011d15 R12: ffffc900030d7948 R13: ffffc900030d7908 R14: ffffc900030d7cf0 R15: ffffc900030d793c arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:339 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:365 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x25e/0x770 mm/slub.c:5270 lsm_file_alloc security/security.c:169 [inline] security_file_alloc+0x34/0x2b0 security/security.c:2380 init_file+0x93/0x4c0 fs/file_table.c:159 alloc_empty_file+0x73/0x1e0 fs/file_table.c:241 alloc_file fs/file_table.c:354 [inline] alloc_file_pseudo+0x13a/0x230 fs/file_table.c:383 sock_alloc_file+0x50/0x210 net/socket.c:483 sock_map_fd net/socket.c:513 [inline] __sys_socket+0x1c0/0x260 net/socket.c:1756 __do_sys_socket net/socket.c:1761 [inline] __se_sys_socket net/socket.c:1759 [inline] __x64_sys_socket+0x72/0xb0 net/socket.c:1759 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f806378f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f80646a4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 00007f80639e6090 RCX: 00007f806378f749 RDX: 0000000000000106 RSI: 0000000000000001 RDI: 000000000000000a RBP: 00007f8063813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f80639e6128 R14: 00007f80639e6090 R15: 00007ffde299c338