rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=fe4c/1/0x4000000000000000 softirq=32936/32941 fqs=14 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8452/1:b..l P5820/1:b..l rcu: (detected by 1, t=10502 jiffies, g=29369, q=408 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8615 Comm: syz.1.570 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:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:107 [inline] RIP: 0010:raw_atomic_try_cmpxchg_acquire include/linux/atomic/atomic-arch-fallback.h:2170 [inline] RIP: 0010:atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1302 [inline] RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] RIP: 0010:do_raw_spin_lock+0x121/0x290 kernel/locking/spinlock_debug.c:116 Code: 0f 84 f3 00 00 00 c7 44 24 40 00 00 00 00 48 89 df be 04 00 00 00 e8 fe f8 88 00 48 8d 7c 24 40 be 04 00 00 00 e8 ef f8 88 00 <8b> 44 24 40 b9 01 00 00 00 f0 0f b1 0b 0f 85 dd 00 00 00 65 8b 1d RSP: 0018:ffffc90000007ba0 EFLAGS: 00000097 RAX: 00000000ffffff01 RBX: ffff888040e872a8 RCX: ffffffff819e9541 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000007be0 RBP: ffffc90000007c60 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000000f7c R12: ffff888040e872b8 R13: ffff888040e872b0 R14: 1ffff110081d0e57 R15: 1ffff110081d0e56 FS: 0000555565358500(0000) GS:ffff888125c07000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000002000 CR3: 000000007c646000 CR4: 00000000003526f0 Call Trace: spin_lock include/linux/spinlock.h:344 [inline] advance_sched+0xc4/0xc90 net/sched/sch_taprio.c:930 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x51c/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:65 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:140 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline] RIP: 0010:kasan_check_range+0x50/0x2c0 mm/kasan/generic.c:200 Code: 49 b9 00 00 00 00 00 80 ff ff eb 11 cc cc cc f3 0f 1e fa 49 b9 00 00 00 00 00 00 00 ff f3 0f 1e fa 4c 39 cf 0f 82 58 02 00 00 <49> 89 ff 49 c1 ef 03 49 ba 00 00 00 00 00 fc ff df 4f 8d 1c 17 49 RSP: 0018:ffffc900033e7298 EFLAGS: 00000202 RAX: ffffffff82187a01 RBX: ffff888077d15dc0 RCX: ffffffff82187afd RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff9a7b0440 RBP: 00007f95a45f6000 R08: ffffffff9a7b0444 R09: ffff800000000000 R10: dffffc0000000000 R11: ffffed100efa2bc9 R12: 1ffff9200067cef5 R13: 00007f95a45f6000 R14: 1ffff1100efa2bb8 R15: 1ffff9200067cefd instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_inc include/linux/atomic/atomic-instrumented.h:435 [inline] vma_iter_store_overwrite+0x11d/0x8e0 mm/vma.h:525 vma_iter_store_new mm/vma.h:551 [inline] vma_complete+0x224/0xae0 mm/vma.c:351 __split_vma+0x8b0/0xa00 mm/vma.c:564 vms_gather_munmap_vmas+0x4c6/0x12f0 mm/vma.c:1421 __mmap_setup mm/vma.c:2403 [inline] __mmap_region mm/vma.c:2727 [inline] mmap_region+0x729/0x1d10 mm/vma.c:2823 do_mmap+0xc45/0x10d0 mm/mmap.c:558 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:581 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f95a638f783 Code: f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 41 89 ca 41 f7 c1 ff 0f 00 00 75 14 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 25 c3 0f 1f 40 00 48 c7 c0 a8 ff ff ff 64 c7 RSP: 002b:00007ffd161ee8e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f95a65e6308 RCX: 00007f95a638f783 RDX: 0000000000000003 RSI: 0000000000400000 RDI: 00007f95a41f6000 RBP: 00007f95a65e6270 R08: 00000000000000db R09: 0000000000000000 R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000003 R13: 00007f95a65e6270 R14: 000000000000163c R15: 0000000000000003 task:syz-executor state:R running task stack:19496 pid:5820 tgid:5820 ppid:5815 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14ed/0x5040 kernel/sched/core.c:6894 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7078 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:392 [inline] copy_pte_range mm/memory.c:1331 [inline] copy_pmd_range+0x74f2/0x7e00 mm/memory.c:1392 copy_pud_range mm/memory.c:1429 [inline] copy_p4d_range mm/memory.c:1453 [inline] copy_page_range+0xb88/0x11d0 mm/memory.c:1535 dup_mmap+0xf4a/0x1b80 mm/mmap.c:1827 dup_mm kernel/fork.c:1529 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1581 copy_process+0x1812/0x3ba0 kernel/fork.c:2218 kernel_clone+0x21e/0x820 kernel/fork.c:2648 __do_sys_clone kernel/fork.c:2789 [inline] __se_sys_clone kernel/fork.c:2773 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2773 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa360785e93 RSP: 002b:00007fffe5527208 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa360785e93 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000555565c007d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 000000000005b7c9 R15: 00007fffe55273a0 task:syz.1.536 state:R running task stack:21472 pid:8452 tgid:8452 ppid:5824 task_flags:0x40064c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14ed/0x5040 kernel/sched/core.c:6894 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221 irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__kasan_check_byte+0x6/0x40 mm/kasan/common.c:572 Code: f6 5b 41 5c 41 5e 41 5f e9 c7 fa ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 41 56 <53> 48 89 f3 49 89 fe e8 3e 15 00 00 84 c0 75 16 be 01 00 00 00 4c RSP: 0018:ffffc900034c6d28 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8173fd92 RDI: ffffffff8e13efa0 RBP: ffffffff8173fd75 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc900034c6ef8 R11: ffffffff81acb2b0 R12: 0000000000000002 R13: ffffffff8e13efa0 R14: 0000000000000000 R15: 0000000000000000 kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire+0x84/0x340 kernel/locking/lockdep.c:5842 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1436 [inline] free_unref_folios+0xcc0/0x13e0 mm/page_alloc.c:3033 folios_put_refs+0x584/0x670 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x49e/0x1490 mm/shmem.c:1137 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+0x178/0x670 kernel/entry/common.c:196 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f95a624f6b7 RSP: 002b:00007f95a714b120 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007f95a638f749 RDX: 00007f95a714b140 RSI: 00007f95a714b270 RDI: 000000000000000b RBP: 00007f95a6413f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f95a65e6128 R14: 00007f95a65e6090 R15: 00007ffd161ee828 rcu: rcu_preempt kthread starved for 10474 jiffies! g29369 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:27904 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14ed/0x5040 kernel/sched/core.c:6894 __schedule_loop kernel/sched/core.c:6976 [inline] schedule+0x165/0x360 kernel/sched/core.c:6991 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297 kthread+0x389/0x480 kernel/kthread.c:467 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: CPU: 1 UID: 0 PID: 7324 Comm: syz-executor 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:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xcc5/0x1260 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 94 a3 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 3f 9f 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 23 9f RSP: 0018:ffffc9001ac3f640 EFLAGS: 00000293 RAX: ffffffff81b51b9d RBX: 1ffff110170c85c9 RCX: ffff88802dbd3c80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9001ac3f768 R08: ffffffff8fa25d77 R09: 1ffffffff1f44bae R10: dffffc0000000000 R11: fffffbfff1f44baf R12: ffff8880b8642e48 R13: dffffc0000000000 R14: ffff8880b873bdc0 R15: 0000000000000000 FS: 000055556aa0e500(0000) GS:ffff888125d07000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f73c43156c0 CR3: 000000002e63a000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline] flush_tlb_mm_range+0x60a/0x1170 arch/x86/mm/tlb.c:1472 dup_mmap+0x15fa/0x1b80 mm/mmap.c:1866 dup_mm kernel/fork.c:1529 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1581 copy_process+0x1812/0x3ba0 kernel/fork.c:2218 kernel_clone+0x21e/0x820 kernel/fork.c:2648 __do_sys_clone kernel/fork.c:2789 [inline] __se_sys_clone kernel/fork.c:2773 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2773 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f73c3585e93 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffc75e9f078 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f73c3585e93 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055556aa0e7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 000000000005ae7b R15: 00007ffc75e9f210