rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12049/1:b..l rcu: (detected by 1, t=10502 jiffies, g=45373, q=711 ncpus=2) task:syz.3.2192 state:R running task stack:23400 pid:12049 tgid:12048 ppid:5823 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6965 preempt_schedule+0xae/0xc0 kernel/sched/core.c:6989 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __local_bh_enable_ip+0x13e/0x1c0 kernel/softirq.c:414 local_bh_enable include/linux/bottom_half.h:33 [inline] bpf_test_run+0x3fc/0x830 net/bpf/test_run.c:437 bpf_prog_test_run_skb+0xb30/0x1560 net/bpf/test_run.c:1099 bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4429 __sys_bpf+0x4a4/0x860 kernel/bpf/syscall.c:5854 __do_sys_bpf kernel/bpf/syscall.c:5943 [inline] __se_sys_bpf kernel/bpf/syscall.c:5941 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5941 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: 0033:0x7ff8bab8e929 RSP: 002b:00007ff8bba63038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007ff8badb5fa0 RCX: 00007ff8bab8e929 RDX: 000000000000002c RSI: 0000200000000080 RDI: 000000000000000a RBP: 00007ff8bac10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff8badb5fa0 R15: 00007ffe325c94d8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10485 jiffies! g45373 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=26221 rcu: rcu_preempt kthread starved for 10486 jiffies! g45373 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:27128 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+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 12053 Comm: syz.9.2194 Not tainted 6.16.0-rc4-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:taprio_set_budgets+0x12b/0x3b0 net/sched/sch_taprio.c:666 Code: e8 48 c1 e8 03 48 89 44 24 10 31 db 45 31 e4 4c 89 6c 24 18 bf 10 00 00 00 4c 89 e6 e8 7e c2 39 f8 49 83 fc 0f 48 89 6c 24 30 <0f> 87 8a 01 00 00 4d 8d 2c 2f 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 RSP: 0018:ffffc90000007c00 EFLAGS: 00000093 RAX: ffffffff89869102 RBX: 0000000000000004 RCX: ffff8880320c1e00 RDX: 0000000000010000 RSI: 0000000000000001 RDI: 0000000000000010 RBP: 0000000000000008 R08: ffff8880246a9483 R09: 1ffff110048d5290 R10: dffffc0000000000 R11: ffffed10048d5291 R12: 0000000000000001 R13: 0000000000000000 R14: ffff8880292e52e0 R15: ffff8880246a9400 FS: 00005555760c5500(0000) GS:ffff888125c50000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3c8a71 CR3: 0000000080115000 CR4: 0000000000350ef0 Call Trace: advance_sched+0x963/0xc90 net/sched/sch_taprio.c:977 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5896 Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 9b ca fe 10 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000f0cf8f0 EFLAGS: 00000206 RAX: c34399faaf4d0300 RBX: 0000000000000202 RCX: c34399faaf4d0300 RDX: 0000000000000000 RSI: ffffffff8db6ee09 RDI: ffffffff8be28c80 RBP: ffff8880320c28f0 R08: ffffc9000f0cfec0 R09: ffffc9000f0cfa78 R10: dffffc0000000000 R11: fffff52001e19f51 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8e13ee20 R15: ffff8880320c1e00 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4643 [inline] kmem_cache_free+0x2f6/0x400 mm/slub.c:4745 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdad338e929 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:00007ffe17d738b8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000004f9a2 RCX: 00007fdad338e929 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fdad35b7ba0 R08: 0000000000000001 R09: 0000000417d73baf R10: 00007fdad3200000 R11: 0000000000000246 R12: 00007fdad35b5fac R13: 00007fdad35b5fa0 R14: ffffffffffffffff R15: 00007ffe17d739d0