rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P407/1:b..l P402/1:b..l rcu: (detected by 1, t=10503 jiffies, g=195057, q=71 ncpus=2) task:rm state:R running task stack:24360 pid:402 ppid:366 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:bpf_tree_comp kernel/bpf/core.c:632 [inline] RIP: 0010:__lt_find include/linux/rbtree_latch.h:115 [inline] RIP: 0010:latch_tree_find include/linux/rbtree_latch.h:208 [inline] RIP: 0010:bpf_ksym_find kernel/bpf/core.c:708 [inline] RIP: 0010:is_bpf_text_address+0x127/0x2a0 kernel/bpf/core.c:742 Code: 4d 85 ff 0f 84 be 00 00 00 4c 89 24 24 c1 e3 03 8d 2c 5b 48 f7 dd 4d 8d a4 2f e0 fd ff ff 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 e7 e8 ff 27 4b 00 4d 8b 24 24 4c 89 e7 4c 89 f6 e8 20 RSP: 0018:ffffc9000545f108 EFLAGS: 00000246 RAX: 1ffffffff1c7b17b RBX: 0000000000000000 RCX: ffff88802a94bc00 RDX: 0000000000000000 RSI: ffffffff8b1cfa00 RDI: ffffffff8b1cf9c0 RBP: 0000000000000000 R08: dffffc0000000000 R09: 1ffffffff223cea0 R10: dffffc0000000000 R11: fffffbfff223cea1 R12: ffffffff8e3d8bd8 R13: dffffc0000000000 R14: 00007ff12d3312c7 R15: ffffffff8e3d8df8 kernel_text_address+0xa0/0xd0 kernel/extable.c:125 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x290 mm/slub.c:3852 mas_destroy+0x1a45/0x20a0 lib/maple_tree.c:5593 mas_store_prealloc+0x2f2/0x430 lib/maple_tree.c:5465 vma_complete+0x202/0xb40 mm/mmap.c:532 __split_vma+0xa9e/0xc20 mm/mmap.c:2425 mprotect_fixup+0xade/0xcd0 mm/mprotect.c:650 do_mprotect_pkey+0x7c3/0xcc0 mm/mprotect.c:819 __do_sys_mprotect mm/mprotect.c:840 [inline] __se_sys_mprotect mm/mprotect.c:837 [inline] __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:837 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7ff12d3312c7 RSP: 002b:00007ffd6643c108 EFLAGS: 00000206 ORIG_RAX: 000000000000000a RAX: ffffffffffffffda RBX: 00007ff12d30db20 RCX: 00007ff12d3312c7 RDX: 0000000000000001 RSI: 0000000000001000 RDI: 00007ff12d069000 RBP: 00007ffd6643c3d0 R08: 0000000000000000 R09: 00007ff12d0a32e0 R10: 00007ff12d30db20 R11: 0000000000000206 R12: 0000000000000018 R13: 00000295fbb9d4a4 R14: 0000000000000000 R15: 00007ff12d345310 task:syz.6.6185 state:R running task stack:27272 pid:407 ppid:20027 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] collapse_huge_page mm/khugepaged.c:1167 [inline] hpage_collapse_scan_pmd+0x28a5/0x4050 mm/khugepaged.c:1393 madvise_collapse+0x680/0xd80 mm/khugepaged.c:2747 madvise_vma_behavior mm/madvise.c:1092 [inline] madvise_walk_vmas mm/madvise.c:1266 [inline] do_madvise+0x92f/0x3760 mm/madvise.c:1446 __do_sys_madvise mm/madvise.c:1459 [inline] __se_sys_madvise mm/madvise.c:1457 [inline] __x64_sys_madvise+0xa6/0xc0 mm/madvise.c:1457 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f5753f9de59 RSP: 002b:00007f5754e80028 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007f5754226180 RCX: 00007f5753f9de59 RDX: 0000000000000019 RSI: 0000000000600000 RDI: 0000200000000000 RBP: 00007f5754033e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5754226218 R14: 00007f5754226180 R15: 00007fff7f228cd8 rcu: rcu_preempt kthread starved for 10541 jiffies! g195057 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:26856 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148 Code: 4c 1d 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 43 77 3c 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2c 89 cb 80 f9 RSP: 0018:ffffffff8ce07d80 EFLAGS: 000002c6 RAX: a7c424d5c75cf900 RBX: ffffffff81628b01 RCX: a7c424d5c75cf900 RDX: 0000000000000001 RSI: ffffffff8acacb60 RDI: ffffffff8b1cfa20 RBP: ffffffff8ce07eb8 R08: ffff8880b8e36bab R09: 1ffff110171c6d75 R10: dffffc0000000000 R11: ffffed10171c6d76 R12: 1ffffffff19c0fbc R13: dffffc0000000000 R14: 1ffffffff19d2688 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a2850d6a38 CR3: 0000000064c5f000 CR4: 00000000003506f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:753 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97 cpuidle_idle_call kernel/sched/idle.c:178 [inline] do_idle+0x221/0x5c0 kernel/sched/idle.c:302 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401 rest_init+0x2e2/0x300 init/main.c:744 arch_call_rest_init+0xe/0x10 init/main.c:840 start_kernel+0x461/0x4e0 init/main.c:1085 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555 x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536 secondary_startup_64_no_verify+0x179/0x17b