rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6520/1:b..l rcu: (detected by 1, t=10502 jiffies, g=18065, q=678 ncpus=2) task:sed state:R running task stack:23904 pid:6520 tgid:6520 ppid:6519 task_flags:0x400000 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:kasan_check_range+0x0/0x2c0 mm/kasan/generic.c:199 Code: fe 90 0f 0b 48 89 df 48 c7 c6 0f c8 16 8e e8 e7 30 f8 fe 90 0f 0b cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <0f> 1f 40 d6 55 41 57 41 56 41 55 41 54 53 b0 01 48 85 f6 0f 84 ae RSP: 0018:ffffc90003907870 EFLAGS: 00000202 RAX: ffffffff82474501 RBX: 0000000000000010 RCX: ffffffff824746cd RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc90003907aa0 RBP: 0000000000000100 R08: ffffc90003907acf R09: 1ffff92000720f59 R10: dffffc0000000000 R11: fffff52000720f5a R12: ffffffff824746cd R13: 1ffff92000720f5b R14: ffffc90003907ac0 R15: ffffc90003907aa0 __asan_memcpy+0x40/0x70 mm/kasan/shadow.c:106 nd_jump_root+0x1cd/0x430 fs/namei.c:1143 path_init+0x433/0x1330 fs/namei.c:2717 path_lookupat+0x2a/0x8c0 fs/namei.c:2800 filename_lookup+0x256/0x5d0 fs/namei.c:2839 vfs_statx+0xfc/0x200 fs/stat.c:353 vfs_fstatat+0x11b/0x170 fs/stat.c:373 __do_sys_newfstatat fs/stat.c:538 [inline] __se_sys_newfstatat fs/stat.c:532 [inline] __x64_sys_newfstatat+0x151/0x200 fs/stat.c:532 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f43411deeaa RSP: 002b:00007ffea2a3c968 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007ffea2a3c97b RCX: 00007f43411deeaa RDX: 00007ffea2a3ca20 RSI: 00007ffea2a3c970 RDI: 00000000ffffff9c RBP: 00007ffea2a3cae0 R08: 00007ffea2a3cb67 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000022 R13: 00007f43411b3050 R14: 0000000000000001 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 4179 jiffies! g18065 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:27648 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 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: 6495 Comm: syz.2.18 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xce5/0x12c0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 d4 eb 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 7f e7 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 63 e7 RSP: 0018:ffffc90003837440 EFLAGS: 00000293 RAX: ffffffff81b9cd6d RBX: 1ffff110170c8525 RCX: ffff88807ebc5b80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003837580 R08: ffffffff9011ccb7 R09: 1ffffffff2023996 R10: dffffc0000000000 R11: fffffbfff2023997 R12: ffff8880b8642928 R13: dffffc0000000000 R14: ffff8880b873c000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125557000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbb2579bab8 CR3: 000000000e54c000 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+0x5c3/0x10c0 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:505 [inline] tlb_flush_mmu+0x1af/0xa30 mm/mmu_gather.c:404 tlb_finish_mmu+0xf9/0x230 mm/mmu_gather.c:530 free_ldt_pgtables+0x19d/0x350 arch/x86/kernel/ldt.c:411 arch_exit_mmap arch/x86/include/asm/mmu_context.h:232 [inline] exit_mmap+0x1af/0xa10 mm/mmap.c:1287 __mmput+0x118/0x430 kernel/fork.c:1175 exit_mm+0x168/0x220 kernel/exit.c:581 do_exit+0x6a2/0x23c0 kernel/exit.c:964 do_group_exit+0x21b/0x2d0 kernel/exit.c:1118 get_signal+0x1284/0x1330 kernel/signal.c:3034 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __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 include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa863f99d8b Code: Unable to access opcode bytes at 0x7fa863f99d61. RSP: 002b:00007fa864dfef60 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffffc RBX: 00000000ffffff75 RCX: 00007fa863f99d8b RDX: 00007fa864dfefe0 RSI: 0000000040085507 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00007fa864300320 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 00002000000002c0 R13: 0000000000000000 R14: 00007fa8641d5fa0 R15: 00007fff99fafe28