rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=652c/1/0x4000000000000000 softirq=159706/159706 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P141/1:b..l P27025/1:b..l P17998/1:b..l rcu: (detected by 1, t=10505 jiffies, g=155337, q=798 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 27010 Comm: udevadm Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:114 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:128 [inline] RIP: 0010:lock_is_held_type+0x4d/0x150 kernel/locking/lockdep.c:5936 Code: 39 fe 90 07 85 c0 0f 85 d5 00 00 00 65 4c 8b 2d 81 b8 90 07 41 83 bd 8c 0b 00 00 00 0f 85 bf 00 00 00 89 f5 49 89 fe 9c 41 5c 48 c7 c7 11 f6 fb 8d e8 b6 19 00 00 65 ff 05 ff fd 90 07 41 83 RSP: 0018:ffffc90000007cd8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 0000000000010000 RDX: ffff888029700000 RSI: 00000000ffffffff RDI: ffff88802039c2c0 RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000000f90 R12: 0000000000000046 R13: ffff888029700000 R14: ffff88802039c2c0 R15: dffffc0000000000 FS: 00007f1cc624b880(0000) GS:ffff888125290000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feee7c4f0d1 CR3: 000000007a501000 CR4: 0000000000350ef0 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] advance_sched+0x14c/0xc20 net/sched/sch_taprio.c:933 __run_hrtimer kernel/time/hrtimer.c:1930 [inline] __hrtimer_run_queues+0x3c0/0xa20 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:98 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:115 [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+0x97/0x2c0 mm/kasan/generic.c:200 Code: 00 fc ff df 4d 8d 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 3d 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00 <0f> 85 9e 01 00 00 49 ff c3 48 ff c3 75 ee e9 1d 01 00 00 44 89 dd RSP: 0018:ffffc900052d7920 EFLAGS: 00000246 RAX: ffffffff82479001 RBX: ffffffffffffffff RCX: ffffffff8247901c RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc900052d7c60 RBP: ffffc900052d7a50 R08: ffffc900052d7c6f R09: 1ffff92000a5af8d R10: dffffc0000000000 R11: fffff52000a5af8d R12: 0000000000000002 R13: ffff8880787dc4c8 R14: fffff52000a5af8e R15: 1ffff92000a5af8c __asan_memcpy+0x40/0x70 mm/kasan/shadow.c:106 step_into_slowpath+0x37c/0x7e0 fs/namei.c:2118 step_into fs/namei.c:2148 [inline] walk_component fs/namei.c:2284 [inline] link_path_walk+0xd50/0x18d0 fs/namei.c:2652 path_lookupat+0xe4/0x8c0 fs/namei.c:2808 filename_lookup+0x256/0x5d0 fs/namei.c:2838 do_readlinkat+0xe3/0x510 fs/stat.c:571 __do_sys_readlink fs/stat.c:605 [inline] __se_sys_readlink fs/stat.c:602 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:602 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1cc5b153a7 Code: 00 00 90 48 83 ec 10 48 63 ff 45 31 c9 45 31 c0 6a 00 31 c9 e8 8a 20 f9 ff 48 83 c4 18 c3 0f 1f 44 00 00 b8 59 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 21 ba 0d 00 f7 d8 64 89 02 48 RSP: 002b:00007ffd0618b818 EFLAGS: 00000246 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00007ffd0618bcf0 RCX: 00007f1cc5b153a7 RDX: 0000000000000400 RSI: 00007ffd0618b820 RDI: 00007ffd0618bcf0 RBP: 00007ffd0618b820 R08: 000055625d3fa5d3 R09: 0000000000000000 R10: 000055625d3f1da1 R11: 0000000000000246 R12: 0000000000000400 R13: 00005562566e56b2 R14: 000055625d3fa5d3 R15: 00007ffd0618c930 task:syz-executor state:R running task stack:22248 pid:17998 tgid:17998 ppid:17982 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7189 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7370 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:190 spin_unlock include/linux/spinlock.h:390 [inline] copy_pte_range mm/memory.c:1331 [inline] copy_pmd_range+0x4f04/0x5970 mm/memory.c:1392 copy_pud_range mm/memory.c:1429 [inline] copy_p4d_range mm/memory.c:1453 [inline] copy_page_range+0xbe8/0x11f0 mm/memory.c:1539 dup_mmap+0xf40/0x1d90 mm/mmap.c:1840 dup_mm kernel/fork.c:1534 [inline] copy_mm+0x13b/0x4a0 kernel/fork.c:1586 copy_process+0x1f1c/0x4440 kernel/fork.c:2264 kernel_clone+0x284/0x8f0 kernel/fork.c:2721 __do_sys_clone kernel/fork.c:2862 [inline] __se_sys_clone kernel/fork.c:2846 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2846 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa0ce3c5852 RSP: 002b:00007ffff3e285d0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffff3e285d0 RCX: 00007fa0ce3c5852 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffff3e2875c R08: 0000000000000000 R09: 0000000000000001 R10: 0000555583b4e7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 00000000001a7d52 R15: 00007ffff3e287b0 task:sed state:R running task stack:25608 pid:27025 tgid:27025 ppid:27024 task_flags:0x400000 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7189 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x730 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2d7/0x3c0 kernel/locking/lockdep.c:5893 Code: 64 97 11 00 00 00 00 eb b5 e8 85 63 06 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 75 1e 97 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 45 5f 6e ff cc 48 8d 3d f2 1f 92 RSP: 0018:ffffc9000528f308 EFLAGS: 00000282 RAX: 73198106c4876c00 RBX: 0000000000000202 RCX: 0000000000000046 RDX: 0000000000000000 RSI: ffffffff8e2189dd RDI: ffffffff8c28ac60 RBP: ffff888034600b90 R08: ffffffff847369f2 R09: ffffffff8e95cd60 R10: ffffc9000528f600 R11: ffffc9000528f780 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8e95cd60 R15: ffff888034600000 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] ima_match_policy+0x2141/0x21e0 security/integrity/ima/ima_policy.c:804 ima_get_action+0x75/0xb0 security/integrity/ima/ima_api.c:201 process_measurement+0x2ec/0x1c80 security/integrity/ima/ima_main.c:283 ima_file_mmap+0x121/0x200 security/integrity/ima/ima_main.c:515 security_mmap_file+0x773/0xa20 security/security.c:2581 vm_mmap_pgoff+0x134/0x4f0 mm/util.c:575 elf_map fs/binfmt_elf.c:400 [inline] elf_load+0x247/0x6b0 fs/binfmt_elf.c:423 load_elf_binary+0x1173/0x2980 fs/binfmt_elf.c:1188 search_binary_handler fs/exec.c:1664 [inline] exec_binprm fs/exec.c:1696 [inline] bprm_execve+0x94a/0x1440 fs/exec.c:1748 do_execveat_common+0x50d/0x690 fs/exec.c:1846 __do_sys_execve fs/exec.c:1930 [inline] __se_sys_execve fs/exec.c:1924 [inline] __x64_sys_execve+0x97/0xc0 fs/exec.c:1924 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbccf2a3107 RSP: 002b:00007ffc07309ce8 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00005592f667e190 RCX: 00007fbccf2a3107 RDX: 00005592f667e1b8 RSI: 00005592f667e190 RDI: 00005592f667e270 RBP: 00005592f667e270 R08: 00007ffc0730edbe R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 00005592f667e1b8 R13: 00007fbccf468e8b R14: 00005592f667e1b8 R15: 0000000000000000 task:kworker/u8:6 state:R running task stack:21720 pid:141 tgid:141 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-btrfs-135) Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7189 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7370 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 vprintk_emit+0x4c5/0x560 kernel/printk/printk.c:2480 _printk+0xdd/0x130 kernel/printk/printk.c:2504 _btrfs_printk+0x29a/0x320 fs/btrfs/messages.c:236 writepage_delalloc+0x159b/0x1e70 fs/btrfs/extent_io.c:1527 extent_writepage fs/btrfs/extent_io.c:1889 [inline] extent_write_cache_pages fs/btrfs/extent_io.c:2552 [inline] btrfs_writepages+0x14d3/0x2410 fs/btrfs/extent_io.c:2684 do_writepages+0x32e/0x550 mm/page-writeback.c:2571 __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764 writeback_sb_inodes+0x979/0x19d0 fs/fs-writeback.c:2056 wb_writeback+0x445/0xb00 fs/fs-writeback.c:2241 wb_do_writeback fs/fs-writeback.c:2388 [inline] wb_workfn+0x3f8/0xf10 fs/fs-writeback.c:2428 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 10505 jiffies! g155337 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:27736 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 27026 Comm: syz.1.4418 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d d4 93 60 0c 48 89 de 5b e9 b3 ea 5f 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d b8 43 73 11 65 8b 15 d9 43 73 11 81 e2 00 01 ff 00 74 RSP: 0018:ffffc900054af558 EFLAGS: 00000202 RAX: ffffffff81b9bb36 RBX: ffff8880b873c148 RCX: 0000000000080000 RDX: ffffc900128e5000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc900054af6a0 R08: ffffffff9030a7f7 R09: 1ffffffff20614fe R10: dffffc0000000000 R11: fffffbfff20614ff R12: 1ffff110170c8589 R13: dffffc0000000000 R14: ffff8880b8642c48 R15: 0000000000000000 FS: 00007feee8b426c0(0000) GS:ffff888125390000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feede7ff000 CR3: 000000005030b000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: csd_lock_wait kernel/smp.c:342 [inline] smp_call_function_many_cond+0xfe6/0x13d0 kernel/smp.c:892 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x5c3/0x10b0 arch/x86/mm/tlb.c:1451 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline] tlb_flush_mmu+0x1af/0xa30 mm/mmu_gather.c:423 tlb_finish_mmu+0xf9/0x230 mm/mmu_gather.c:549 unmap_region+0x2a5/0x330 mm/vma.c:491 vms_clear_ptes mm/vma.c:1303 [inline] vms_complete_munmap_vmas+0x493/0xc60 mm/vma.c:1345 do_vmi_align_munmap+0x3b7/0x4b0 mm/vma.c:1604 do_vmi_munmap+0x252/0x2d0 mm/vma.c:1652 __vm_munmap+0x22c/0x3d0 mm/vma.c:3285 __do_sys_munmap mm/mmap.c:1079 [inline] __se_sys_munmap mm/mmap.c:1076 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1076 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7feee7b9cc07 Code: 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007feee8b41e08 EFLAGS: 00000246 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007feee7b9cc07 RDX: 0000000001000000 RSI: 0000000008400000 RDI: 00007feedd800000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000008 R13: 00007feee8b41ee0 R14: 00007feee8b41ea0 R15: 00007feedd800000