rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=12997 jiffies, g=15009, q=2022 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 12997 (4294963490-4294950493), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 12997 jiffies! g15009 f0x2 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:25624 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 6541 Comm: syz-executor Not tainted 6.13.0-rc1-syzkaller-00172-g6e165f544379 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5853 Code: 2b 00 74 08 4c 89 f7 e8 8a 0a 8b 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc900042ff080 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200085fe1c RCX: ffff888025bf8ad8 RDX: dffffc0000000000 RSI: ffffffff8c0aa9a0 RDI: ffffffff8c5f98c0 RBP: ffffc900042ff1d8 R08: ffffffff942a0887 R09: 1ffffffff2854110 R10: dffffc0000000000 R11: fffffbfff2854111 R12: 1ffff9200085fe18 R13: dffffc0000000000 R14: ffffc900042ff0e0 R15: 0000000000000246 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe0e0053440 CR3: 000000002d710000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] page_ext_get+0x3d/0x2a0 mm/page_ext.c:525 page_table_check_clear+0x4b/0x550 mm/page_table_check.c:74 get_and_clear_full_ptes include/linux/pgtable.h:712 [inline] zap_present_folio_ptes mm/memory.c:1510 [inline] zap_present_ptes mm/memory.c:1595 [inline] do_zap_pte_range mm/memory.c:1697 [inline] zap_pte_range mm/memory.c:1739 [inline] zap_pmd_range mm/memory.c:1822 [inline] zap_pud_range mm/memory.c:1851 [inline] zap_p4d_range mm/memory.c:1872 [inline] unmap_page_range+0x376a/0x48d0 mm/memory.c:1893 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1983 exit_mmap+0x288/0xd50 mm/mmap.c:1263 __mmput+0x115/0x3c0 kernel/fork.c:1406 exit_mm+0x220/0x310 kernel/exit.c:570 do_exit+0x9b2/0x28e0 kernel/exit.c:925 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x16b2/0x1750 kernel/signal.c:3017 arch_do_signal_or_restart+0x96/0x860 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/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f479f176197 Code: Unable to access opcode bytes at 0x7f479f17616d. RSP: 002b:00007fffa52fadc0 EFLAGS: 00000293 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 000000000000199b RCX: 00007f479f176197 RDX: 0000000040000000 RSI: 00007fffa52fadfc RDI: 00000000ffffffff RBP: 00007fffa52fadfc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007fffa52fae80 R13: 00007fffa52fae88 R14: 0000000000000009 R15: 0000000000000000