rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8440/1:b..l rcu: (detected by 0, t=10502 jiffies, g=23777, q=172 ncpus=2) task:syz.3.615 state:R running task stack:23728 pid:8440 tgid:8439 ppid:5833 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6764 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7086 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:debug_lockdep_rcu_enabled+0xd/0x40 kernel/rcu/update.c:320 Code: f5 90 0f 0b 90 90 90 eb c6 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 83 3d 27 98 2c 04 00 <74> 1e 83 3d ca c9 2c 04 00 74 15 65 48 8b 0c 25 c0 d4 03 00 31 c0 RSP: 0018:ffffc9001c2a7698 EFLAGS: 00000202 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff888032b88ae8 RDX: dffffc0000000000 RSI: ffffffff8c0ab8e0 RDI: ffffffff8c5fac60 RBP: ffffc9001c2a7750 R08: ffffffff942c3847 R09: 1ffffffff2858708 R10: dffffc0000000000 R11: fffffbfff2858709 R12: 1ffff92003854ed8 R13: ffff888033bac808 R14: dffffc0000000000 R15: ffffc9001c2a77e0 rcu_read_lock include/linux/rcupdate.h:850 [inline] ___pte_offset_map+0xa7/0x380 mm/pgtable-generic.c:287 __pte_offset_map include/linux/mm.h:3032 [inline] __pte_offset_map_lock+0xc7/0x300 mm/pgtable-generic.c:398 pte_offset_map_lock include/linux/mm.h:3047 [inline] follow_page_pte+0x121/0x1460 mm/gup.c:855 follow_pmd_mask mm/gup.c:978 [inline] follow_pud_mask mm/gup.c:1030 [inline] follow_p4d_mask mm/gup.c:1047 [inline] follow_page_mask mm/gup.c:1090 [inline] __get_user_pages+0xb33/0x4140 mm/gup.c:1489 populate_vma_page_range+0x264/0x330 mm/gup.c:1929 __mm_populate+0x27a/0x460 mm/gup.c:2032 mm_populate include/linux/mm.h:3386 [inline] vm_mmap_pgoff+0x303/0x430 mm/util.c:580 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f95ef98cda9 RSP: 002b:00007f95f071a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f95efba5fa0 RCX: 00007f95ef98cda9 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 00007f95efa0e2a0 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f95efba5fa0 R15: 00007fff70f39178 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g23777 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=16526 rcu: rcu_preempt kthread starved for 10502 jiffies! g23777 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:25624 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6856 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8413 Comm: syz.5.609 Not tainted 6.13.0-syzkaller-09760-g69e858e0b8b2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:87 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:147 [inline] RIP: 0010:lock_release+0x625/0xa30 kernel/locking/lockdep.c:5875 Code: 01 0f 85 9a 00 00 00 4c 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 f8 79 88 00 48 c7 84 24 90 00 00 00 00 00 00 00 9c <8f> 84 24 90 00 00 00 42 80 3c 3b 00 74 08 4c 89 f7 e8 e5 78 88 00 RSP: 0018:ffffc90000a18b58 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 1ffff9200014317e RCX: ffffc90000a18b03 RDX: 0000000000000000 RSI: ffffffff8c0ab8e0 RDI: ffffffff8c5fac60 RBP: ffffc90000a18c90 R08: ffffffff901a1777 R09: 1ffffffff20342ee R10: dffffc0000000000 R11: fffffbfff20342ef R12: 1ffff92000143178 R13: 0000000000000046 R14: ffffc90000a18bf0 R15: dffffc0000000000 FS: 00007f8478c056c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2de2d5 CR3: 0000000066a16000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x79/0x140 kernel/locking/spinlock.c:194 __run_hrtimer kernel/time/hrtimer.c:1734 [inline] __hrtimer_run_queues+0x477/0xd30 kernel/time/hrtimer.c:1802 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1864 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:copy_msghdr_from_user+0xd3/0x680 net/socket.c:2509 Code: e8 32 c4 35 fb 48 89 c3 31 ff 48 89 c6 e8 45 81 14 f8 48 85 db 74 62 e8 5b 7c 14 f8 bb f2 ff ff ff 48 c7 44 24 40 0e 36 e0 45 <48> b8 00 00 00 00 00 fc ff df 48 8b 4c 24 38 c7 04 08 00 00 00 00 RSP: 0018:ffffc9001c177960 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000080000 RDX: ffffc9001c177d30 RSI: 0000000000000000 RDI: ffffc9001c177d28 RBP: ffffc9001c177a70 R08: ffffffff84df2f88 R09: ffffc9001c177d10 R10: ffffc9001c177d50 R11: fffff5200382efac R12: 1ffff9200382ef3b R13: 0000000000000000 R14: ffffc9001c1779d8 R15: 1ffff9200382ef00 recvmsg_copy_msghdr net/socket.c:2754 [inline] ___sys_recvmsg net/socket.c:2826 [inline] do_recvmmsg+0x3bd/0xab0 net/socket.c:2925 __sys_recvmmsg net/socket.c:2999 [inline] __do_sys_recvmmsg net/socket.c:3022 [inline] __se_sys_recvmmsg net/socket.c:3015 [inline] __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3015 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8477d8cda9 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:00007f8478c05038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f8477fa6080 RCX: 00007f8477d8cda9 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000004 RBP: 00007f8477e0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8477fa6080 R15: 00007ffc61e0e7e8