rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=2b6c/1/0x4000000000000000 softirq=19279/19288 fqs=598 rcu: (detected by 1, t=10505 jiffies, g=13029, q=316 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6231 Comm: sed Not tainted 6.16.0-rc5-syzkaller-00121-gbc9ff192a6c9 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:mark_lock+0x15/0x190 kernel/locking/lockdep.c:4725 Code: 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 8b 46 20 89 c1 81 e1 00 00 03 00 <83> f9 01 bb 09 00 00 00 83 db 00 83 fa 08 0f 45 da bd 01 00 00 00 RSP: 0018:ffffc90000007b08 EFLAGS: 00000006 RAX: 00000000000a4007 RBX: 0000000000000001 RCX: 0000000000020000 RDX: 0000000000000008 RSI: ffff88802bda4740 RDI: ffff88802bda3c00 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff898ebf88 R10: dffffc0000000000 R11: ffffed100426e25e R12: 0000000000000003 R13: 0000000000000001 R14: ffff88802bda4740 R15: 0000000000000002 FS: 00007f69f9be8c80(0000) GS:ffff888125c1b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f69f9e42d71 CR3: 000000007a232000 CR4: 0000000000350ef0 Call Trace: mark_usage kernel/locking/lockdep.c:4677 [inline] __lock_acquire+0x6a8/0xd20 kernel/locking/lockdep.c:5194 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] advance_sched+0xa14/0xc90 net/sched/sch_taprio.c:985 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 9b 10 02 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc900032274b0 EFLAGS: 00000206 RAX: a5e308da250f0700 RBX: 0000000000000000 RCX: a5e308da250f0700 RDX: 0000000000000000 RSI: ffffffff8db8660e RDI: ffffffff8be29dc0 RBP: ffffffff81cf1f76 R08: 0000000000000000 R09: ffffffff81cf1f76 R10: dffffc0000000000 R11: ffffffff81ad03a0 R12: 0000000000000002 R13: ffffffff8e13f160 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] is_bpf_text_address+0x47/0x2b0 kernel/bpf/core.c:772 kernel_text_address+0xa5/0xe0 kernel/extable.c:125 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4328 [inline] __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4340 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x28b/0x550 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x58d/0x5d0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x213/0x4b0 security/tomoyo/file.c:822 security_inode_getattr+0x12f/0x330 security/security.c:2377 vfs_getattr fs/stat.c:259 [inline] vfs_fstat fs/stat.c:281 [inline] __do_sys_newfstat fs/stat.c:555 [inline] __se_sys_newfstat fs/stat.c:550 [inline] __x64_sys_newfstat+0xfc/0x200 fs/stat.c:550 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f69f9da2ad7 Code: 73 01 c3 48 8b 0d 21 f3 0d 00 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 05 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 RSP: 002b:00007ffc803612d8 EFLAGS: 00000297 ORIG_RAX: 0000000000000005 RAX: ffffffffffffffda RBX: 000055a016bb62a0 RCX: 00007f69f9da2ad7 RDX: 00007f69f9e80ea0 RSI: 00007ffc803612e0 RDI: 0000000000000003 RBP: 00007f69f9e80ff0 R08: 00007f69f9e82ac0 R09: 0000000000000080 R10: 0000000000000004 R11: 0000000000000297 R12: 00007ffc80361448 R13: 0000000000000000 R14: 00007f69f9c844d0 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 7515 jiffies! g13029 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:26888 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6790 __schedule_loop kernel/sched/core.c:6868 [inline] schedule+0x165/0x360 kernel/sched/core.c:6883 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 6166 Comm: syz-execprog Not tainted 6.16.0-rc5-syzkaller-00121-gbc9ff192a6c9 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:native_pause arch/x86/include/asm/vdso/processor.h:13 [inline] RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline] RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xf67/0x12d0 kernel/smp.c:885 Code: 00 00 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 d0 78 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 7b 74 0b 00 eb 37 90 43 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 60 RSP: 0000:ffffc900048df720 EFLAGS: 00000293 RAX: ffffffff81b4c210 RBX: ffff8880b873b1c0 RCX: ffff888031cc8000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900048df880 R08: ffffffff8fa1f3f7 R09: 1ffffffff1f43e7e R10: dffffc0000000000 R11: fffffbfff1f43e7f R12: 1ffff110170c8385 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8641c28 FS: 000000c000063098(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb1782e3a18 CR3: 0000000078fe1000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x6b1/0x12c0 arch/x86/mm/tlb.c:1451 flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline] ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:101 wp_page_copy mm/memory.c:3635 [inline] do_wp_page+0x1bc2/0x5800 mm/memory.c:4030 handle_pte_fault mm/memory.c:6085 [inline] __handle_mm_fault+0x1144/0x5620 mm/memory.c:6212 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6381 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x472a72 Code: e8 13 a8 00 00 48 8b 4c 24 48 49 89 0b 48 8b 10 49 89 53 08 48 8b 54 24 50 49 89 53 10 48 8b 70 08 49 89 73 18 48 89 44 24 30 <48> 89 08 48 89 50 08 c7 40 10 00 00 00 00 bb 01 00 00 00 e8 f6 2e RSP: 002b:000000c001267778 EFLAGS: 00010246 RAX: 00007fb1782e3a18 RBX: 000000c000063008 RCX: 00000000009efcc0 RDX: 0000000000a0a4e0 RSI: 000000c00004d718 RDI: 00007fb1782e3a18 RBP: 000000c0012677b0 R08: 0000000000033a18 R09: 0000000000000002 R10: 0000000000000001 R11: 0000000000000000 R12: 000000c001267880 R13: 000000c0000101d0 R14: 000000c0003eae00 R15: 000000000000002a