rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6473/1:b..l rcu: (detected by 0, t=10502 jiffies, g=13629, q=1068 ncpus=2) task:modprobe state:R running task stack:24904 pid:6473 tgid:6473 ppid:2939 task_flags:0x400000 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:link_path_walk+0x5b3/0xeb0 fs/namei.c:2470 Code: 89 ee 83 e6 01 31 ff e8 8b 8c 7f ff 40 f6 c5 01 0f 85 26 03 00 00 e8 3c 88 7f ff 4c 89 ea 4c 89 e8 48 c1 e8 03 42 0f b6 04 30 <84> c0 0f 85 f8 03 00 00 0f b6 1a 31 ff 89 de 48 89 d5 e8 16 8b 7f RSP: 0018:ffffc9001b537850 EFLAGS: 00000a03 RAX: 0000000000000000 RBX: ffff88802610fa70 RCX: ffff88802e349e00 RDX: ffff888029f4d526 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000100004 R08: ffffffff8243cd25 R09: ffffffff8243cafb R10: 0000000000000002 R11: ffff88802e349e00 R12: 000000343662696c R13: ffff888029f4d526 R14: dffffc0000000000 R15: ffffc9001b537bd8 path_openat+0x26d/0x35d0 fs/namei.c:4000 do_filp_open+0x284/0x4e0 fs/namei.c:4031 do_sys_openat2+0x12b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x249/0x2a0 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5e0552aa46 RSP: 002b:00007ffc75b27528 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffc75b27788 RCX: 00007f5e0552aa46 RDX: 0000000000080000 RSI: 00007ffc75b275a0 RDI: 00000000ffffff9c RBP: 00007ffc75b27590 R08: 0000000000080000 R09: 00007ffc75b275a0 R10: 0000000000000000 R11: 0000000000000287 R12: 00007ffc75b275a0 R13: 0000000000000001 R14: 00007ffc75b2776f R15: 00000000ffffffff rcu: rcu_preempt kthread starved for 248 jiffies! g13629 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:26688 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 6440 Comm: syz.1.145 Not tainted 6.15.0-rc1-syzkaller-00221-gb65999e7238e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x1bac/0x2d40 kernel/smp.c:885 Code: 03 84 c0 75 7e 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 18 e3 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 c8 de 0b 00 eb 41 f3 90 <48> b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 11 41 f7 45 00 RSP: 0018:ffffc9001b65f380 EFLAGS: 00000293 RAX: ffffffff81b776cd RBX: 1ffff110170e7e91 RCX: ffff88802ba40000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9001b65f580 R08: ffffffff81b77698 R09: 1ffffffff20bef8e R10: dffffc0000000000 R11: fffffbfff20bef8f R12: ffff8880b863ad08 R13: ffff8880b873f488 R14: ffff8880b863ad00 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888124fb0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff90ed79ab8 CR3: 0000000063eb4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1275 [inline] flush_tlb_mm_range+0xb8d/0x13f0 arch/x86/mm/tlb.c:1365 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:480 [inline] tlb_flush_mmu+0x1aa/0x690 mm/mmu_gather.c:403 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:496 exit_mmap+0x5b1/0xde0 mm/mmap.c:1297 __mmput+0x115/0x420 kernel/fork.c:1379 exit_mm+0x221/0x310 kernel/exit.c:589 do_exit+0x994/0x27f0 kernel/exit.c:940 do_group_exit+0x207/0x2c0 kernel/exit.c:1102 get_signal+0x1696/0x1730 kernel/signal.c:3034 arch_do_signal_or_restart+0x98/0x840 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd01f98d169 Code: Unable to access opcode bytes at 0x7fd01f98d13f. RSP: 002b:00007fd020871038 EFLAGS: 00000246 ORIG_RAX: 000000000000010f RAX: 0000000000000001 RBX: 00007fd01fba6160 RCX: 00007fd01f98d169 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000200000000200 RBP: 00007fd01fa0e990 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fd01fba6160 R15: 00007ffc7a206ec8