rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=9d44/1/0x4000000000000000 softirq=197582/197582 fqs=1 rcu: (detected by 1, t=10502 jiffies, g=176157, q=235 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 27538 Comm: syz.0.4670 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:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:417 Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 ab a0 d1 f5 cc RSP: 0018:ffffc90000007c00 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000005 RCX: 0000000080010001 RDX: 0000000000010000 RSI: ffffffff8e144ce0 RDI: ffff8880259647b0 RBP: ffff8880259647b0 R08: ffff8880274c819f R09: 1ffff11004e99033 R10: dffffc0000000000 R11: ffffed1004e99034 R12: 0000000000000001 R13: 0000000000000001 R14: ffffffff8e144ce0 R15: ffff888025963c80 FS: 00007f74b4e946c0(0000) GS:ffff888125bf9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 0000000030ffa000 CR4: 00000000003526f0 Call Trace: find_held_lock kernel/locking/lockdep.c:5350 [inline] __lock_release kernel/locking/lockdep.c:5535 [inline] lock_release+0x10d/0x3b0 kernel/locking/lockdep.c:5889 rcu_lock_release include/linux/rcupdate.h:322 [inline] rcu_read_unlock include/linux/rcupdate.h:881 [inline] advance_sched+0xb23/0xc90 net/sched/sch_taprio.c:993 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x51c/0xc30 kernel/time/hrtimer.c:1849 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1911 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:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x5a/0xb0 kernel/rcu/tree.c:752 Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 ec c0 80 00 48 c7 c3 58 a7 a3 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 34 8b 03 65 ff 0d 29 42 fb 10 74 11 83 e0 04 c1 e8 02 5b RSP: 0018:ffffc9000beceef0 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: ffff8880b8633758 RCX: 0000000080000001 RDX: 000000005a44979c RSI: ffffffff8be09740 RDI: ffffffff8be09700 RBP: 1ffffffff1f46142 R08: ffffffff823091da R09: ffffffff8e144ce0 R10: ffff8880327b0000 R11: fffffbfff1f45b3f R12: 0000000000000006 R13: dffffc0000000000 R14: ffffffff8dbc4dd0 R15: dffffc0000000000 rcu_read_lock_held_common kernel/rcu/update.c:109 [inline] rcu_read_lock_held+0x15/0x50 kernel/rcu/update.c:349 obj_cgroup_memcg include/linux/memcontrol.h:382 [inline] get_mem_cgroup_from_objcg+0xb9/0x1d0 include/linux/memcontrol.h:519 obj_cgroup_charge_pages+0xe/0xa0 mm/memcontrol.c:2855 obj_cgroup_charge_account+0xcf/0x650 mm/memcontrol.c:3160 __memcg_slab_post_alloc_hook+0x3ee/0x820 mm/memcontrol.c:3249 memcg_slab_post_alloc_hook mm/slub.c:2558 [inline] slab_post_alloc_hook mm/slub.c:5198 [inline] slab_alloc_node mm/slub.c:5500 [inline] __do_kmalloc_node mm/slub.c:5893 [inline] __kmalloc_node_track_caller_noprof+0x5f3/0x820 mm/slub.c:6005 __do_krealloc mm/slub.c:7345 [inline] krealloc_node_align_noprof+0x1ae/0x3a0 mm/slub.c:7404 copy_array+0x71/0x100 kernel/bpf/verifier.c:1391 copy_stack_state kernel/bpf/verifier.c:1451 [inline] copy_func_state kernel/bpf/verifier.c:1732 [inline] copy_verifier_state+0x997/0xf90 kernel/bpf/verifier.c:1778 is_state_visited kernel/bpf/verifier.c:20090 [inline] do_check+0x4d82/0xea60 kernel/bpf/verifier.c:20560 do_check_common+0x19cc/0x25b0 kernel/bpf/verifier.c:23909 do_check_main kernel/bpf/verifier.c:23992 [inline] bpf_check+0x5e7a/0x1c300 kernel/bpf/verifier.c:25302 bpf_prog_load+0x13ba/0x1a10 kernel/bpf/syscall.c:3087 __sys_bpf+0x5c3/0x8a0 kernel/bpf/syscall.c:6206 __do_sys_bpf kernel/bpf/syscall.c:6319 [inline] __se_sys_bpf kernel/bpf/syscall.c:6317 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6317 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: 0033:0x7f74b3f8f749 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:00007f74b4e94038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f74b41e5fa0 RCX: 00007f74b3f8f749 RDX: 0000000000000048 RSI: 00002000000017c0 RDI: 0000000000000005 RBP: 00007f74b4013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f74b41e6038 R14: 00007f74b41e5fa0 R15: 00007ffeac7a9cf8 rcu: rcu_preempt kthread starved for 10495 jiffies! g176157 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:26656 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5290 [inline] __schedule+0x14db/0x5030 kernel/sched/core.c:6902 __schedule_loop kernel/sched/core.c:6984 [inline] schedule+0x165/0x360 kernel/sched/core.c:6999 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 26635 Comm: syz-executor 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: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 b4 9a 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 5f 96 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 43 96 RSP: 0018:ffffc9000bdef640 EFLAGS: 00000293 RAX: ffffffff81b5835d RBX: 1ffff110170c85c1 RCX: ffff888028889e40 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000bdef768 R08: ffffffff8fa2d9f7 R09: 1ffffffff1f45b3e R10: dffffc0000000000 R11: fffffbfff1f45b3f R12: ffff8880b8642e08 R13: dffffc0000000000 R14: ffff8880b873bd80 R15: 0000000000000000 FS: 000055555cbc2500(0000) GS:ffff888125cf9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f33ecbd5d58 CR3: 00000000a87d4000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 __flush_tlb_multi arch/x86/include/asm/paravirt.h:57 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline] flush_tlb_mm_range+0x5db/0x1100 arch/x86/mm/tlb.c:1472 dup_mmap+0x15fa/0x1b80 mm/mmap.c:1866 dup_mm kernel/fork.c:1529 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1581 copy_process+0x1812/0x3ba0 kernel/fork.c:2218 kernel_clone+0x21e/0x820 kernel/fork.c:2648 __do_sys_clone kernel/fork.c:2789 [inline] __se_sys_clone kernel/fork.c:2773 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2773 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: 0033:0x7f1912585e93 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:00007ffd79f32d58 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1912585e93 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055555cbc27d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 000000000022baca R15: 00007ffd79f32ef0