rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9226/1:b..l P16462/1:b..l P18233/1:b..l P20420/1:b..l P20913/1:b..l rcu: (detected by 0, t=10502 jiffies, g=103509, q=318 ncpus=2) task:syz.2.3803 state:R running task stack:26248 pid:20913 tgid:20909 ppid:17766 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x19a/0x2d0 kernel/locking/lockdep.c:5893 Code: ee 00 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 65 48 2b 05 bd b8 18 12 0f 85 32 01 00 00 48 83 c4 18 5b 41 5c 41 5d <41> 5e 41 5f e9 3d 7c e1 09 65 8b 05 ca b8 18 12 83 f8 07 0f 87 f2 RSP: 0018:ffffc900033af3b0 EFLAGS: 00000282 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffc900033af38c RDX: 0000000000000001 RSI: ffffffff8daa8a1d RDI: ffffffff8bf2b480 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: ffff88803548aff0 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff88803548a4c0 R15: 0000000000000002 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] blk_cgroup_congested+0x13b/0x270 block/blk-cgroup.c:2245 __folio_throttle_swaprate+0x3d/0x190 mm/swapfile.c:4034 folio_throttle_swaprate include/linux/swap.h:608 [inline] shmem_add_to_page_cache+0x5b6/0xa70 mm/shmem.c:899 shmem_alloc_and_add_folio+0x662/0xc20 mm/shmem.c:1958 shmem_get_folio_gfp+0x67f/0x1610 mm/shmem.c:2556 shmem_fault+0x1fe/0xa00 mm/shmem.c:2757 __do_fault+0x10d/0x490 mm/memory.c:5320 do_read_fault mm/memory.c:5755 [inline] do_fault+0xae4/0x1ad0 mm/memory.c:5889 do_pte_missing mm/memory.c:4401 [inline] handle_pte_fault mm/memory.c:6273 [inline] __handle_mm_fault+0x1919/0x2bb0 mm/memory.c:6411 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6580 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x54e/0x3590 mm/gup.c:1428 populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860 __mm_populate+0x1d8/0x380 mm/gup.c:1963 mm_populate include/linux/mm.h:3701 [inline] vm_mmap_pgoff+0x37f/0x470 mm/util.c:586 ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:604 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbfa0f8f749 RSP: 002b:00007fbfa1dbc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fbfa11e6180 RCX: 00007fbfa0f8f749 RDX: 0000000000000003 RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007fbfa1013f91 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbfa11e6218 R14: 00007fbfa11e6180 R15: 00007fff3169a068 task:syz.1.3661 state:R running task stack:27512 pid:20420 tgid:20420 ppid:16462 task_flags:0x40044c flags:0x0008000a Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7047 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1884 [inline] zap_pmd_range mm/memory.c:1946 [inline] zap_pud_range mm/memory.c:1975 [inline] zap_p4d_range mm/memory.c:1996 [inline] unmap_page_range+0x1047/0x43c0 mm/memory.c:2017 unmap_single_vma+0x153/0x240 mm/memory.c:2059 unmap_vmas+0x218/0x470 mm/memory.c:2101 exit_mmap+0x1b0/0xb60 mm/mmap.c:1277 __mmput+0x12a/0x410 kernel/fork.c:1173 mmput+0x62/0x70 kernel/fork.c:1196 exit_mm kernel/exit.c:581 [inline] do_exit+0x7d7/0x2bd0 kernel/exit.c:959 do_group_exit+0xd3/0x2a0 kernel/exit.c:1112 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x8c/0x540 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+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7eff8d1c2005 RSP: 002b:00007eff8df83f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007eff8d3e6180 RCX: 00007eff8d1c2005 RDX: 00007eff8df83fc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007eff8d213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007eff8d3e6218 R14: 00007eff8d3e6180 R15: 00007ffc30a23628 task:syz-executor state:R running task stack:24056 pid:18233 tgid:18233 ppid:18228 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x183/0x2d0 kernel/locking/lockdep.c:5893 Code: 0f c1 05 28 00 19 12 83 f8 01 0f 85 03 01 00 00 9c 58 f6 c4 02 0f 85 ee 00 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 bd b8 18 12 0f 85 32 01 00 00 48 83 c4 18 5b 41 5c 41 RSP: 0018:ffffc900034d72f0 EFLAGS: 00000206 RAX: 15686e104156dd00 RBX: ffffffff8e3c96a0 RCX: ffffc900034d72fc RDX: 0000000000000001 RSI: ffffffff8daa8a1d RDI: ffffffff8bf2b480 RBP: 0000000000000001 R08: 0000000000000001 R09: 00000000d3f6a143 R10: 0000000000000002 R11: 00000000000a77d1 R12: ffffffff816cca34 R13: 0000000000000206 R14: ffff888077144980 R15: 0000000000000002 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x3f9/0x20b0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:165 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1406 [inline] free_unref_folios+0xa22/0x1610 mm/page_alloc.c:3000 folios_put_refs+0x4be/0x750 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x58f/0x1140 mm/shmem.c:1137 shmem_truncate_range mm/shmem.c:1249 [inline] shmem_evict_inode+0x39e/0xbe0 mm/shmem.c:1379 evict+0x3c2/0xad0 fs/inode.c:837 iput_final fs/inode.c:1954 [inline] iput.part.0+0x621/0x1190 fs/inode.c:2006 iput+0x35/0x40 fs/inode.c:1969 do_unlinkat+0x3d2/0x660 fs/namei.c:5452 __do_sys_unlink fs/namei.c:5483 [inline] __se_sys_unlink fs/namei.c:5481 [inline] __x64_sys_unlink+0xc5/0x110 fs/namei.c:5481 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5f09f8ecf7 RSP: 002b:00007ffdade02378 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5f09f8ecf7 RDX: 00007ffdade023a0 RSI: 00007ffdade02430 RDI: 00007ffdade02430 RBP: 00007ffdade02430 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffdade034c0 R13: 00007f5f0a013d7d R14: 000000000014b8b9 R15: 00007ffdade03500 task:syz-executor state:R running task stack:23704 pid:16462 tgid:16462 ppid:16457 task_flags:0x440940 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_notrace+0x62/0xe0 kernel/sched/core.c:7140 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x8e/0xc0 kernel/rcu/tree.c:752 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x2cd/0x330 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] mem_cgroup_iter+0x5d/0x710 mm/memcontrol.c:1018 shrink_node_memcgs mm/vmscan.c:5981 [inline] shrink_node+0x4d8/0x3bb0 mm/vmscan.c:6061 shrink_zones mm/vmscan.c:6300 [inline] do_try_to_free_pages+0x362/0x1920 mm/vmscan.c:6362 try_to_free_mem_cgroup_pages+0x31b/0x740 mm/vmscan.c:6690 try_charge_memcg+0x42a/0xd30 mm/memcontrol.c:2388 try_charge mm/memcontrol.c:2530 [inline] charge_memcg+0x8a/0x230 mm/memcontrol.c:4728 __mem_cgroup_charge+0x2b/0x1e0 mm/memcontrol.c:4745 mem_cgroup_charge include/linux/memcontrol.h:663 [inline] filemap_add_folio+0xe6/0x610 mm/filemap.c:959 page_cache_ra_unbounded+0x3d1/0x9e0 mm/readahead.c:280 do_page_cache_ra mm/readahead.c:332 [inline] page_cache_ra_order+0xbf4/0xed0 mm/readahead.c:535 do_sync_mmap_readahead mm/filemap.c:3400 [inline] filemap_fault+0x16ac/0x29d0 mm/filemap.c:3549 __do_fault+0x10d/0x490 mm/memory.c:5320 do_read_fault mm/memory.c:5755 [inline] do_fault+0xae4/0x1ad0 mm/memory.c:5889 do_pte_missing mm/memory.c:4401 [inline] handle_pte_fault mm/memory.c:6273 [inline] __handle_mm_fault+0x1919/0x2bb0 mm/memory.c:6411 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6580 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x64/0xc0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7eff8d065fd4 RSP: 002b:00007ffc30a239b0 EFLAGS: 00010202 RAX: 0000001b31524000 RBX: 000000000000036a RCX: 000000000014c468 RDX: 0000000007197ac8 RSI: 00007eff8dfc7010 RDI: 001a80358ffd515f RBP: 00007ffc30a239ec R08: 0000000000000000 R09: 00007eff8dfc7000 R10: 0000000000000001 R11: 00000000000410ca R12: 0000000000001388 R13: 00000000000927c0 R14: 000000000014c605 R15: 00007ffc30a23a40 task:syz-executor state:R running task stack:23640 pid:9226 tgid:9226 ppid:9219 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:kasan_byte_accessible+0x18/0x30 mm/kasan/generic.c:212 Code: 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 b8 00 00 00 00 00 fc ff df 48 c1 ef 03 48 01 c7 0f b6 07 <3c> 07 0f 96 c0 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f RSP: 0018:ffffc900053972b0 EFLAGS: 00000286 RAX: 0000000000000000 RBX: ffffffff8e3c96a0 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffffffff81d07bf6 RDI: fffffbfff1c792d4 RBP: ffffffff8e3c96a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: ffff88807a788b30 R12: ffffffff81d07bf6 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 __kasan_check_byte+0x13/0x50 mm/kasan/common.c:573 kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire kernel/locking/lockdep.c:5842 [inline] lock_acquire+0xfc/0x330 kernel/locking/lockdep.c:5825 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] is_bpf_text_address+0x36/0x1a0 kernel/bpf/core.c:744 kernel_text_address kernel/extable.c:125 [inline] kernel_text_address+0x8d/0x100 kernel/extable.c:94 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x59/0xa0 arch/x86/kernel/unwind_orc.c:385 arch_stack_walk+0xa6/0x100 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:165 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1406 [inline] free_unref_folios+0xa22/0x1610 mm/page_alloc.c:3000 folios_put_refs+0x4be/0x750 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x58f/0x1140 mm/shmem.c:1137 shmem_truncate_range mm/shmem.c:1249 [inline] shmem_evict_inode+0x39e/0xbe0 mm/shmem.c:1379 evict+0x3c2/0xad0 fs/inode.c:837 iput_final fs/inode.c:1954 [inline] iput.part.0+0x621/0x1190 fs/inode.c:2006 iput+0x35/0x40 fs/inode.c:1969 do_unlinkat+0x3d2/0x660 fs/namei.c:5452 __do_sys_unlink fs/namei.c:5483 [inline] __se_sys_unlink fs/namei.c:5481 [inline] __x64_sys_unlink+0xc5/0x110 fs/namei.c:5481 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4d68b8ecf7 RSP: 002b:00007ffd999d1b78 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4d68b8ecf7 RDX: 00007ffd999d1ba0 RSI: 00007ffd999d1c30 RDI: 00007ffd999d1c30 RBP: 00007ffd999d1c30 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffd999d2cc0 R13: 00007f4d68c13d7d R14: 000000000014b9a4 R15: 00007ffd999d2d00 rcu: rcu_preempt kthread starved for 10622 jiffies! g103509 f0x0 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:28440 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 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: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 86 5f 02 c3 cc cc cc cc 0f 1f 00 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 13 f9 11 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6 RAX: 0000000005307a6f RBX: 0000000000000000 RCX: ffffffff8b7866d9 RDX: 0000000000000000 RSI: ffffffff8daceab2 RDI: ffffffff8bf2b480 RBP: fffffbfff1c12f68 R08: 0000000000000001 R09: ffffed101708673d R10: ffff8880b84339eb R11: ffffffff8e098670 R12: 0000000000000000 R13: ffffffff8e097b40 R14: ffffffff9088bdd0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881248f4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f822ff8 CR3: 00000000761c5000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 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+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x38d/0x510 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3ef/0x4d0 init/main.c:1206 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148