rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5835/2:b..l P11155/1:b..l P11149/1:b..l rcu: (detected by 0, t=10503 jiffies, g=46541, q=527 ncpus=2) task:syz.7.1177 state:R running task stack:22368 pid:11149 tgid:11149 ppid:6791 task_flags:0x40064c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:xa_entry include/linux/xarray.h:1226 [inline] RIP: 0010:xas_find+0x43e/0x990 lib/xarray.c:1423 Code: 00 00 fc ff df 80 3c 08 00 74 08 4c 89 f7 e8 39 5e cf f6 49 8b 2e e8 b1 dc 01 00 41 89 c6 31 ff 89 c6 e8 35 42 69 f6 45 85 f6 <74> 33 49 83 c5 18 4c 89 ef be ff ff ff ff e8 4f d9 01 00 41 89 c6 RSP: 0018:ffffc9000409f130 EFLAGS: 00000202 RAX: ffffffff8b57b9cb RBX: ffffc9000409f258 RCX: 0000000000000000 RDX: ffff88802ec63d00 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffea00011c49c0 R08: ffff88802ec63d00 R09: 0000000000000002 R10: 0000000000000003 R11: 0000000000000000 R12: ffffc9000409f240 R13: ffff88802f2ceb28 R14: 0000000000000001 R15: 1ffff92000813e4b find_get_entry mm/filemap.c:2062 [inline] find_lock_entries+0x1ff/0xa60 mm/filemap.c:2166 shmem_undo_range+0x254/0x1490 mm/shmem.c:1119 shmem_truncate_range mm/shmem.c:1249 [inline] shmem_evict_inode+0x26e/0xa70 mm/shmem.c:1379 evict+0x5f4/0xae0 fs/inode.c:837 __dentry_kill+0x209/0x660 fs/dcache.c:670 finish_dput+0xc9/0x480 fs/dcache.c:879 __fput+0x68e/0xa70 fs/file_table.c:476 task_work_run+0x1d4/0x260 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x694/0x22f0 kernel/exit.c:971 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop kernel/entry/common.c:75 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x177/0x660 kernel/entry/common.c:196 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f1b2018f751 RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f1b203e6090 RCX: 00007f1b2018f749 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007f1b20213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f1b203e6128 R14: 00007f1b203e6090 R15: 00007ffd6bf48108 task:syz.7.1181 state:R running task stack:21024 pid:11155 tgid:11155 ppid:6791 task_flags:0x400640 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:rcu_lock_release include/linux/rcupdate.h:341 [inline] RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:897 [inline] RIP: 0010:pte_unmap include/linux/pgtable.h:136 [inline] RIP: 0010:follow_page_pte+0xcf2/0x13e0 mm/gup.c:889 Code: c4 b1 b5 ff c6 05 84 d6 60 0d 01 48 c7 c7 60 8e 76 8b be 80 03 00 00 48 c7 c2 a0 8e 76 8b e8 05 f2 92 ff 48 8d 35 00 00 00 00 <48> c7 c7 a0 1a f4 8d e8 b2 d8 92 ff e8 4d 68 9c ff eb 13 e8 86 b1 RSP: 0018:ffffc90003b2e960 EFLAGS: 00000293 RAX: ffffffff820b45c3 RBX: 0000000000000001 RCX: ffff88802e788000 RDX: 0000000000000000 RSI: ffffffff820b4622 RDI: ffffffff8bc08380 RBP: ffffc90003b2ea50 R08: ffff888038451063 R09: 1ffff1100708a20c R10: dffffc0000000000 R11: ffffed100708a20d R12: dffffc0000000000 R13: 0000000000000000 R14: ffffea0002268600 R15: 8000000089a18007 follow_pmd_mask mm/gup.c:-1 [inline] follow_pud_mask mm/gup.c:967 [inline] follow_p4d_mask mm/gup.c:984 [inline] follow_page_mask mm/gup.c:1023 [inline] __get_user_pages+0xa6c/0x29f0 mm/gup.c:1426 __get_user_pages_locked mm/gup.c:1692 [inline] get_dump_page+0x1ac/0x3f0 mm/gup.c:2192 dump_user_range+0x1de/0xc90 fs/coredump.c:1366 elf_core_dump+0x3369/0x3960 fs/binfmt_elf.c:2111 coredump_write+0x1121/0x18b0 fs/coredump.c:1049 do_coredump fs/coredump.c:1126 [inline] vfs_coredump+0x3321/0x3e60 fs/coredump.c:1200 get_signal+0x1108/0x1340 kernel/signal.c:3019 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop kernel/entry/common.c:75 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x177/0x660 kernel/entry/common.c:196 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f1b2004f6b7 RSP: 002b:00007f1b2104c120 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007f1b2018f749 RDX: 00007f1b2104c140 RSI: 00007f1b2104c270 RDI: 000000000000000b RBP: 00007f1b20213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f1b203e6128 R14: 00007f1b203e6090 R15: 00007ffd6bf48108 task:syz-executor state:R running task stack:21592 pid:5835 tgid:5835 ppid:5815 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2d8/0x3b0 kernel/locking/lockdep.c:5893 Code: 14 e2 10 00 00 00 00 eb b5 e8 64 6f bb 09 f7 c3 00 02 00 00 74 b9 65 48 8b 05 74 ce e1 10 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 44 1f 72 ff cc 48 8d 3d 11 48 e7 RSP: 0018:ffffc90003bdf498 EFLAGS: 00000282 RAX: 2cd13e188fbba200 RBX: 0000000000000202 RCX: 0000000000000046 RDX: 0000000000000001 RSI: ffffffff8d975e82 RDI: ffffffff8bc083e0 RBP: ffff88802ad1c858 R08: ffffea0002516137 R09: 1ffffd40004a2c26 R10: dffffc0000000000 R11: fffff940004a2c27 R12: 0000000000000001 R13: 0000000000000001 R14: ffffffff8df41aa0 R15: ffff88802ad1bd00 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] page_ref_add_unless include/linux/page_ref.h:239 [inline] folio_ref_add_unless include/linux/page_ref.h:248 [inline] folio_try_get+0x1d1/0x340 include/linux/page_ref.h:264 find_get_entry mm/filemap.c:2076 [inline] find_lock_entries+0x24f/0xa60 mm/filemap.c:2166 shmem_undo_range+0x254/0x1490 mm/shmem.c:1119 shmem_truncate_range mm/shmem.c:1249 [inline] shmem_evict_inode+0x26e/0xa70 mm/shmem.c:1379 evict+0x5f4/0xae0 fs/inode.c:837 __dentry_kill+0x209/0x660 fs/dcache.c:670 finish_dput+0xc9/0x480 fs/dcache.c:879 __fput+0x68e/0xa70 fs/file_table.c:476 task_work_run+0x1d4/0x260 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xef/0x4e0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbb9cf8e3aa RSP: 002b:00007fffb570e300 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007fbb9cf8e3aa RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fffb570e35c R08: 0000000000000000 R09: 00007fffb570e067 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000110 R13: 000000000000004b R14: 00000000000ab568 R15: 00007fffb570e3b0 rcu: rcu_preempt kthread starved for 10661 jiffies! g46541 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:27616 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 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+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 3e b4 b6 f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 73 c1 0e 00 f3 0f 1e fa fb f4 13 b4 b6 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197e20 EFLAGS: 000002c2 RAX: 0000000001076959 RBX: ffffffff819713ee RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d791f69 RDI: ffffffff8bc083e0 RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8f822170 R13: 1ffff110038dbb70 R14: 0000000000000001 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125f21000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563d23faaa38 CR3: 000000007d3a3000 CR4: 0000000000350ef0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1be/0x4d0 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147