rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12166/1:b..l rcu: (detected by 0, t=10502 jiffies, g=49573, q=770 ncpus=2) task:syz.6.1606 state:R running task stack:23240 pid:12166 tgid:12166 ppid:11513 task_flags:0x400640 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 2b 9e fb 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9001126e398 EFLAGS: 00000206 RAX: 4749064d6183b100 RBX: 0000000000000000 RCX: 4749064d6183b100 RDX: 0000000000000000 RSI: ffffffff8db5aaa7 RDI: ffffffff8be1b7c0 RBP: ffffffff81729af5 R08: 0000000000000000 R09: ffffffff81729af5 R10: ffffc9001126e558 R11: ffffffff81acf5a0 R12: 0000000000000002 R13: ffffffff8e13eda0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf7/0x1f0 mm/page_owner.c:156 __set_page_owner+0x8d/0x4a0 mm/page_owner.c:329 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21d5/0x22b0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2438 shmem_alloc_folio mm/shmem.c:1851 [inline] shmem_alloc_and_add_folio+0x447/0xf60 mm/shmem.c:1890 shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2532 shmem_get_folio mm/shmem.c:2638 [inline] shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3288 generic_perform_write+0x2c7/0x910 mm/filemap.c:4112 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3463 __kernel_write_iter+0x390/0x860 fs/read_write.c:619 dump_emit_page fs/coredump.c:1112 [inline] dump_user_range+0x873/0xc70 fs/coredump.c:1186 elf_core_dump+0x32ed/0x3900 fs/binfmt_elf.c:2075 do_coredump+0x2809/0x3440 fs/coredump.c:950 get_signal+0x10d9/0x1310 kernel/signal.c:3019 arch_do_signal_or_restart+0x9a/0x750 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:330 [inline] irqentry_exit_to_user_mode+0x81/0x120 kernel/entry/common.c:184 exc_general_protection+0x171/0x200 arch/x86/kernel/traps.c:792 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617 RIP: 0033:0x7f977ab8e931 RSP: 002b:00002000000001d0 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f977adb5fa0 RCX: 00007f977ab8e929 RDX: 0000200000000080 RSI: 00002000000001d0 RDI: 0000000080000080 RBP: 00007f977ac10b39 R08: 00002000000002c0 R09: 00002000000002c0 R10: 0000200000000200 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f977adb5fa0 R15: 00007ffd0c3376d8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10474 jiffies! g49573 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=49285 rcu: rcu_preempt kthread starved for 10475 jiffies! g49573 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:27320 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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: 12174 Comm: syz.3.1615 Not tainted 6.16.0-rc2-syzkaller-00278-g3f75bfff44be #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:kasan_check_range+0x1d3/0x2c0 mm/kasan/generic.c:189 Code: 4d 01 f3 49 8d 5c 24 07 4d 85 e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 12 41 80 3b 00 0f 85 b8 00 00 00 49 ff c3 49 ff cc 75 ee <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 45 84 ff 75 63 41 RSP: 0018:ffffc90000a08c98 EFLAGS: 00000056 RAX: ffffffff8b5b5701 RBX: 0000000000000000 RCX: ffffffff8b5b57a6 RDX: 0000000000000001 RSI: 0000000000000018 RDI: ffff88806d66b340 RBP: 0000000000000000 R08: ffff88806d66b357 R09: 1ffff1100dacd66a R10: dffffc0000000000 R11: ffffed100dacd66b R12: 0000000000000003 R13: dffffc0000000000 R14: ffffed100dacd66b R15: 1ffff1100dacd668 FS: 00007f154ef476c0(0000) GS:ffff888125d83000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000000f000 CR3: 000000001d2b8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __asan_memset+0x22/0x50 mm/kasan/shadow.c:84 rb_link_node include/linux/rbtree.h:63 [inline] rb_add_cached include/linux/rbtree.h:182 [inline] timerqueue_add+0x186/0x200 lib/timerqueue.c:40 __run_hrtimer kernel/time/hrtimer.c:1778 [inline] __hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:139 [inline] RIP: 0010:wrmsrq arch/x86/include/asm/msr.h:199 [inline] RIP: 0010:native_x2apic_icr_write arch/x86/include/asm/apic.h:233 [inline] RIP: 0010:__x2apic_send_IPI_dest arch/x86/kernel/apic/x2apic_phys.c:113 [inline] RIP: 0010:x2apic_send_IPI+0x73/0xe0 arch/x86/kernel/apic/x2apic_phys.c:50 Code: 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 75 42 41 8b 16 0f ae f0 0f ae e8 83 fb 02 b8 00 04 00 00 0f 45 c3 b9 30 08 00 00 0f 30 <66> 90 5b 41 5c 41 5e 41 5f 5d c3 cc cc cc cc cc 89 fe 89 fd 48 c7 RSP: 0018:ffffc9001127f830 EFLAGS: 00000206 RAX: 00000000000000fb RBX: 00000000000000fb RCX: 0000000000000830 RDX: 0000000000000000 RSI: 00000000000000fb RDI: 0000000000000000 RBP: ffffc9001127f910 R08: ffffffff8f9fe2f7 R09: 1ffffffff1f3fc5e R10: dffffc0000000000 R11: ffffffff81703110 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff8880b86201b0 R15: ffffffff8db92c60 arch_send_call_function_single_ipi arch/x86/include/asm/smp.h:95 [inline] send_call_function_single_ipi kernel/smp.c:118 [inline] __smp_call_single_queue+0x1cb/0x370 kernel/smp.c:411 generic_exec_single+0x20e/0x500 kernel/smp.c:444 smp_call_function_single_async+0x79/0x110 kernel/smp.c:724 rdmsr_safe_on_cpu+0x127/0x230 arch/x86/lib/msr-smp.c:179 msr_read+0x14d/0x250 arch/x86/kernel/msr.c:66 vfs_read+0x200/0x980 fs/read_write.c:570 ksys_read+0x145/0x250 fs/read_write.c:715 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f154e18e929 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:00007f154ef47038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f154e3b5fa0 RCX: 00007f154e18e929 RDX: 0000000000018ff8 RSI: 0000200000001a40 RDI: 000000000000000a RBP: 00007f154e210b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f154e3b5fa0 R15: 00007ffe9345d708