rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P32431/1:b..l P32392/1:b..l rcu: (detected by 0, t=10502 jiffies, g=196513, q=247 ncpus=2) task:syz.8.7787 state:R running task stack:25768 pid:32392 ppid:26230 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 unwind_next_frame+0x200f/0x2970 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf7/0x1f0 mm/page_owner.c:128 __reset_page_owner+0x4e/0x190 mm/page_owner.c:149 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1154 [inline] free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336 free_unref_page_list+0xbe/0x860 mm/page_alloc.c:2475 release_pages+0x1fa0/0x2220 mm/swap.c:1022 __folio_batch_release+0x71/0xe0 mm/swap.c:1042 folio_batch_release include/linux/pagevec.h:83 [inline] truncate_inode_pages_range+0x358/0xf00 mm/truncate.c:396 evict+0x499/0x870 fs/inode.c:707 do_unlinkat+0x37b/0x570 fs/namei.c:4406 do_coredump+0x1c10/0x2480 fs/coredump.c:744 get_signal+0x1133/0x1400 kernel/signal.c:2888 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315 exc_page_fault+0x8f/0x110 arch/x86/mm/fault.c:1524 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7ff991e4f6b7 RSP: 002b:00007ff992dcc120 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007ff991f8f749 RDX: 00007ff992dcc140 RSI: 00007ff992dcc270 RDI: 000000000000000b RBP: 00007ff992013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ff9921e6038 R14: 00007ff9921e5fa0 R15: 00007ffd1dea59d8 task:syz.4.7804 state:R running task stack:25320 pid:32431 ppid:28972 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:lock_acquire+0x1f2/0x410 kernel/locking/lockdep.c:5758 Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00 RSP: 0018:ffffc9000c777760 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 3ef537d150115b00 RDX: 0000000000000000 RSI: ffffffff8aaace60 RDI: ffffffff8afc6f40 RBP: ffffc9000c777868 R08: dffffc0000000000 R09: 1ffffffff21b52a0 R10: dffffc0000000000 R11: fffffbfff21b52a1 R12: 1ffff920018eeef8 R13: ffffffff8cd2fee0 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] __pte_offset_map+0x48/0x2c0 mm/pgtable-generic.c:287 __pte_offset_map_lock+0x47/0x1e0 mm/pgtable-generic.c:371 pte_offset_map_lock include/linux/mm.h:3016 [inline] __get_locked_pte mm/memory.c:1823 [inline] get_locked_pte include/linux/mm.h:2741 [inline] insert_page mm/memory.c:1865 [inline] vm_insert_page+0x548/0x8b0 mm/memory.c:2021 kcov_mmap+0xe9/0x160 kernel/kcov.c:505 call_mmap include/linux/fs.h:2023 [inline] mmap_file mm/internal.h:98 [inline] __mmap_region mm/mmap.c:2790 [inline] mmap_region+0xfa5/0x2020 mm/mmap.c:2941 do_mmap+0x92f/0x10a0 mm/mmap.c:1385 vm_mmap_pgoff+0x1c0/0x400 mm/util.c:556 ksys_mmap_pgoff+0x520/0x700 mm/mmap.c:1431 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8a4bd8f783 RSP: 002b:00007ffcaf4c8338 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f8a4bfe6308 RCX: 00007f8a4bd8f783 RDX: 0000000000000003 RSI: 0000000000400000 RDI: 00007f8a49bb4000 RBP: 00007f8a4bfe6270 R08: 00000000000000db R09: 0000000000000000 R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000003 R13: 00007f8a4bfe6270 R14: 000000000000078c R15: 0000000000000003 rcu: rcu_preempt kthread starved for 10378 jiffies! g196513 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:26568 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148 Code: cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d c3 f4 38 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56 RSP: 0018:ffffc90000187de0 EFLAGS: 000002c2 RAX: dd9f90d3423c5300 RBX: ffffffff8161981b RCX: dd9f90d3423c5300 RDX: 0000000000000001 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f40 RBP: ffffc90000187f20 R08: ffff8880b8f36b2b R09: 1ffff110171e6d65 R10: dffffc0000000000 R11: ffffed10171e6d66 R12: ffffffff8e4a8e28 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff1100364e780 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc114696008 CR3: 0000000030b84000 CR4: 00000000003506e0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:753 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97 cpuidle_idle_call kernel/sched/idle.c:170 [inline] do_idle+0x1eb/0x510 kernel/sched/idle.c:282 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380 start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323 secondary_startup_64_no_verify+0x179/0x17b