rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=068c/1/0x4000000000000000 softirq=222066/222066 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1020/1:b..l rcu: (detected by 0, t=10506 jiffies, g=170449, q=210 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 1031 Comm: syz.6.9851 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:114 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:128 [inline] RIP: 0010:lock_is_held_type+0x6c/0x190 kernel/locking/lockdep.c:5936 Code: 8b 2c 25 08 20 6e 92 41 83 bd 2c 0b 00 00 00 0f 85 d8 00 00 00 89 f5 49 89 fe 48 c7 04 24 00 00 00 00 9c 8f 04 24 4c 8b 24 24 48 c7 c7 9a 02 72 8d e8 07 17 00 00 65 ff 05 10 4b 28 07 41 83 RSP: 0018:ffffc90000a08c28 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 0000000000010000 RDX: ffff88808d168000 RSI: 00000000ffffffff RDI: ffff88807a197300 RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200014117c R12: 0000000000000046 R13: ffff88808d168000 R14: ffff88807a197300 R15: ffff888052e47c00 FS: 0000000000000000(0000) GS:ffff88812623e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000089030 CR3: 000000003106b000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] advance_sched+0x1d2/0xc90 net/sched/sch_taprio.c:934 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 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+0x55/0xb0 kernel/rcu/tree.c:751 Code: bd 92 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 1c 6b 7f 00 48 c7 c3 d8 4f 6f 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 99 d1 c7 10 74 11 83 e0 RSP: 0018:ffffc90003ae6cf0 EFLAGS: 00000212 RAX: 1ffff110171265fb RBX: ffff8880b8932fd8 RCX: 836e724877319000 RDX: ffffc90003ae6e01 RSI: ffffffff8bbf05c0 RDI: ffffffff8bbf0580 RBP: dffffc0000000000 R08: ffffc90003ae7a10 R09: ffffc90003ae6e98 R10: dffffc0000000000 R11: fffff5200075cdd5 R12: ffffc90003ae7a20 R13: ffffffff81738d25 R14: ffffffff8d92bdd8 R15: dffffc0000000000 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x4b/0x3e0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [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 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:311 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:2963 folios_put_refs+0x584/0x670 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1120 shmem_truncate_range mm/shmem.c:1232 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1360 evict+0x504/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 __fput+0x68e/0xa70 fs/file_table.c:476 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:966 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7c2ad8efc9 Code: Unable to access opcode bytes at 0x7f7c2ad8ef9f. RSP: 002b:00007f7c2bcc70e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f7c2afe6098 RCX: 00007f7c2ad8efc9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7c2afe6098 RBP: 00007f7c2afe6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7c2afe6128 R14: 00007ffc28c303c0 R15: 00007ffc28c304a8 task:syz.7.9850 state:R running task stack:25064 pid:1020 tgid:1018 ppid:31429 task_flags:0x400040 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5893 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 4b ba d0 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:ffffc90003ccf278 EFLAGS: 00000206 RAX: f6c4db2818268100 RBX: 0000000000000206 RCX: f6c4db2818268100 RDX: 0000000000000001 RSI: ffffffff8d8f29f0 RDI: ffffffff8bbf05e0 RBP: ffff88807c45e618 R08: ffff88807e3be1e3 R09: 1ffff1100fc77c3c R10: dffffc0000000000 R11: ffffed100fc77c3d R12: 0000000000000001 R13: 0000000000000001 R14: ffffffff8df3d2e0 R15: ffff88807c45dac0 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] pte_unmap include/linux/pgtable.h:136 [inline] do_wp_page+0x1046/0x5800 mm/memory.c:4135 handle_pte_fault mm/memory.c:6193 [inline] __handle_mm_fault+0x1033/0x5400 mm/memory.c:6318 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6487 do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0010:__put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:104 Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca e9 72 b4 ca f5 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 01 cb <89> 01 31 c9 0f 01 ca e9 4c b4 ca f5 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90003ccf8b8 EFLAGS: 00050202 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000200000089030 RDX: ffff88807c45dac0 RSI: 0000000000000002 RDI: 00000000ffffffff RBP: ffffc90003ccfa30 R08: ffffc90003ccf667 R09: 1ffff92000799ecc R10: dffffc0000000000 R11: fffff52000799ecd R12: 0000000000000002 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000200000089000 ____sys_recvmsg+0x2ab/0x460 net/socket.c:2863 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2892 do_recvmmsg+0x307/0x770 net/socket.c:2987 __sys_recvmmsg net/socket.c:3061 [inline] __do_sys_recvmmsg net/socket.c:3084 [inline] __se_sys_recvmmsg net/socket.c:3077 [inline] __x64_sys_recvmmsg+0x190/0x240 net/socket.c:3077 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0712f8efc9 RSP: 002b:00007f0713e19038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f07131e6090 RCX: 00007f0712f8efc9 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004 RBP: 00007f0713011f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f07131e6128 R14: 00007f07131e6090 R15: 00007ffd62c97848 rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g170449 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=97348 rcu: rcu_preempt kthread starved for 10506 jiffies! g170449 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27288 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245