rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6095/1:b..l rcu: (detected by 1, t=10502 jiffies, g=11729, q=421 ncpus=2) task:syz.2.24 state:R running task stack:26080 pid:6095 tgid:6095 ppid:5955 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 preempt_schedule_notrace+0x57/0x90 kernel/sched/core.c:7140 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:752 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x4b/0x3b0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] get_mem_cgroup_from_objcg+0x1ab/0x1d0 include/linux/memcontrol.h:522 __memcg_slab_post_alloc_hook+0x124/0x730 mm/memcontrol.c:3185 memcg_slab_post_alloc_hook mm/slub.c:2338 [inline] slab_post_alloc_hook mm/slub.c:4964 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_lru_noprof+0x41f/0x6e0 mm/slub.c:5282 __d_alloc+0x37/0x6f0 fs/dcache.c:1730 d_alloc_pseudo+0x21/0xc0 fs/dcache.c:1861 alloc_path_pseudo fs/file_table.c:363 [inline] alloc_file_pseudo+0xcc/0x210 fs/file_table.c:379 __anon_inode_getfile fs/anon_inodes.c:166 [inline] anon_inode_getfile+0xc5/0x1a0 fs/anon_inodes.c:204 bpf_link_prime+0xfc/0x220 kernel/bpf/syscall.c:3448 bpf_raw_tp_link_attach+0x49a/0x6c0 kernel/bpf/syscall.c:4259 bpf_raw_tracepoint_open+0x1b2/0x220 kernel/bpf/syscall.c:4296 __sys_bpf+0x73e/0x860 kernel/bpf/syscall.c:6206 __do_sys_bpf kernel/bpf/syscall.c:6274 [inline] __se_sys_bpf kernel/bpf/syscall.c:6272 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6272 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fea6178f749 RSP: 002b:00007ffe23863be8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fea619e5fa0 RCX: 00007fea6178f749 RDX: 0000000000000010 RSI: 0000200000000540 RDI: 0000000000000011 RBP: 00007fea61813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fea619e5fa0 R14: 00007fea619e5fa0 R15: 0000000000000003 rcu: rcu_preempt kthread starved for 3964 jiffies! g11729 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:27416 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 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+0x510/0xa50 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: 5946 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data kernel/kcov.c:246 [inline] RIP: 0010:__sanitizer_cov_trace_switch+0x8f/0x130 kernel/kcov.c:351 Code: 00 00 00 41 57 41 56 41 54 53 48 8b 54 24 20 65 4c 8b 04 25 08 10 80 92 45 31 c9 eb 08 49 ff c1 4c 39 c8 74 77 4e 8b 54 ce 10 <65> 44 8b 1d 59 12 bf 10 41 81 e3 00 01 ff 00 74 13 41 81 fb 00 01 RSP: 0018:ffffc90000007408 EFLAGS: 00000012 RAX: 0000000000000020 RBX: ffff88813ff33268 RCX: 0000000000000005 RDX: ffffffff81c4d760 RSI: ffffffff8df9aa30 RDI: 0000000000000004 RBP: 0000003bdacf9969 R08: ffff88802df61e80 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000010000 R12: ffff88813ff33010 R13: 0000000000000004 R14: 0000000000042724 R15: 0000000000000258 FS: 0000000000000000(0000) GS:ffff888125e1f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff176a1168 CR3: 000000000dd3a000 CR4: 00000000003526f0 Call Trace: rb_read_data_buffer+0x110/0x580 kernel/trace/ring_buffer.c:1862 check_buffer+0x28a/0x750 kernel/trace/ring_buffer.c:4410 __rb_reserve_next+0x592/0xdb0 kernel/trace/ring_buffer.c:4509 rb_reserve_next_event kernel/trace/ring_buffer.c:4646 [inline] ring_buffer_lock_reserve+0xbb5/0x1010 kernel/trace/ring_buffer.c:4705 __trace_buffer_lock_reserve kernel/trace/trace.c:1079 [inline] trace_event_buffer_lock_reserve+0x1d0/0x6f0 kernel/trace/trace.c:2808 trace_event_buffer_reserve+0x1ef/0x2d0 kernel/trace/trace_events.c:672 do_trace_event_raw_event_bpf_trace_printk kernel/trace/bpf_trace.h:11 [inline] trace_event_raw_event_bpf_trace_printk+0x100/0x260 kernel/trace/bpf_trace.h:11 __do_trace_bpf_trace_printk kernel/trace/bpf_trace.h:11 [inline] trace_bpf_trace_printk+0x153/0x1b0 kernel/trace/bpf_trace.h:11 ____bpf_trace_printk kernel/trace/bpf_trace.c:379 [inline] bpf_trace_printk+0x11e/0x190 kernel/trace/bpf_trace.c:362 bpf_prog_b1367f0be6c54012+0x39/0x3f bpf_dispatcher_nop_func include/linux/bpf.h:1378 [inline] __bpf_prog_run include/linux/filter.h:723 [inline] bpf_prog_run include/linux/filter.h:730 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline] bpf_trace_run1+0x27f/0x4c0 kernel/trace/bpf_trace.c:2115 __bpf_trace_rcu_utilization+0xa1/0xf0 include/trace/events/rcu.h:27 __traceiter_rcu_utilization+0x7a/0xb0 include/trace/events/rcu.h:27 __do_trace_rcu_utilization include/trace/events/rcu.h:27 [inline] trace_rcu_utilization+0x191/0x1c0 include/trace/events/rcu.h:27 rcu_sched_clock_irq+0x81/0x1140 kernel/rcu/tree.c:2693 update_process_times+0x23c/0x2f0 kernel/time/timer.c:2474 tick_sched_handle kernel/time/tick-sched.c:298 [inline] tick_nohz_handler+0x3e9/0x710 kernel/time/tick-sched.c:319 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x4d0/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xcc5/0x1260 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 e4 97 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 8f 93 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 73 93 RSP: 0018:ffffc900045cf4a0 EFLAGS: 00000293 RAX: ffffffff81b5644d RBX: 1ffff110170e8129 RCX: ffff88802df61e80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900045cf5e0 R08: ffffffff8f822377 R09: 1ffffffff1f0446e R10: dffffc0000000000 R11: fffffbfff1f0446f R12: ffff8880b8740948 R13: dffffc0000000000 R14: ffff8880b863bb00 R15: 0000000000000001 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+0x60a/0x1170 arch/x86/mm/tlb.c:1472 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline] tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497 free_ldt_pgtables+0x17b/0x320 arch/x86/kernel/ldt.c:411 arch_exit_mmap arch/x86/include/asm/mmu_context.h:234 [inline] exit_mmap+0x174/0xb10 mm/mmap.c:1263 __mmput+0x118/0x430 kernel/fork.c:1173 exit_mm+0x169/0x230 kernel/exit.c:581 do_exit+0x627/0x22f0 kernel/exit.c:959 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4e0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1bafd85853 Code: Unable to access opcode bytes at 0x7f1bafd85829. RSP: 002b:00007ffc891810f8 EFLAGS: 00000202 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 000000000000173c RCX: 00007f1bafd85853 RDX: 0000000040000000 RSI: 00007ffc8918110c RDI: 00000000ffffffff RBP: 00007ffc8918110c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002 R13: 00007ffc89181178 R14: 00007ffc891813f8 R15: 0000000000000000