rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=b7bc/1/0x4000000000000000 softirq=23894/23900 fqs=1 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5193/1:b..l P3510/1:b..l rcu: (detected by 1, t=10502 jiffies, g=17789, q=724 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6927 Comm: dhcpcd-run-hook Not tainted 6.15.0-rc6-syzkaller-00052-g9f35e33144ae #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:472 [inline] RIP: 0010:lock_release+0x287/0x3e0 kernel/locking/lockdep.c:5889 Code: 89 f6 48 8b 54 24 18 e8 57 30 00 00 48 8b 5c 24 08 48 c7 c7 34 6f 93 8d e8 06 10 b8 09 b8 ff ff ff ff 65 0f c1 05 49 79 d7 10 <83> f8 01 75 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 RSP: 0018:ffffc90000007c38 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000087 RCX: 3fb07aed7f0cf400 RDX: 0000000000000000 RSI: ffffffff8d936f34 RDI: ffffffff8bc1d820 RBP: ffff88802c3fa8f0 R08: ffffffff8f7efb77 R09: 1ffffffff1efdf6e R10: dffffc0000000000 R11: fffffbfff1efdf6f R12: 0000000000000000 R13: 0000000000000000 R14: ffff8880b88276d8 R15: ffff88802c3f9e00 FS: 00007f861e1cfc80(0000) GS:ffff8881260c7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f861e46b7b8 CR3: 000000007cfe6000 CR4: 0000000000350ef0 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x70/0x110 kernel/locking/spinlock.c:194 __run_hrtimer kernel/time/hrtimer.c:1757 [inline] __hrtimer_run_queues+0x408/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__unwind_start+0x5ab/0x760 arch/x86/kernel/unwind_orc.c:755 Code: 0f 96 c0 20 c8 3c 01 75 27 48 8b 44 24 08 80 3c 30 00 4c 8b 64 24 18 74 08 4c 89 e7 e8 4e f3 af 00 48 8b 44 24 10 49 39 04 24 <0f> 87 1b fb ff ff 48 89 df e8 f7 d1 ff ff 48 be 00 00 00 00 00 fc RSP: 0018:ffffc9000b2e7968 EFLAGS: 00000287 RAX: ffffc9000b2e7a50 RBX: ffffc9000b2e79c8 RCX: 0000000000000001 RDX: ffffc9000b2e7a58 RSI: dffffc0000000000 RDI: ffffc9000b2e7968 RBP: 1ffff9200165cf3a R08: ffffc9000b2e7a01 R09: ffffc9000b2e79c8 R10: dffffc0000000000 R11: fffff5200165cf45 R12: ffffc9000b2e7a00 R13: ffffc9000b2e79d8 R14: 1ffff9200165cf3b R15: ffffc9000b2e79d0 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 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] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4358 kmalloc_noprof include/linux/slab.h:905 [inline] slab_free_hook mm/slub.c:2332 [inline] slab_free mm/slub.c:4642 [inline] kmem_cache_free+0x169/0x3f0 mm/slub.c:4744 fput_close_sync+0x119/0x200 fs/file_table.c:570 __do_sys_close fs/open.c:1581 [inline] __se_sys_close fs/open.c:1566 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1566 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f861e31f407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffcfe2d86c0 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 00007f861e1cfc80 RCX: 00007f861e31f407 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000b RBP: 00005640687f7018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 task:kworker/u8:8 state:R running task stack:21368 pid:3510 tgid:3510 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 preempt_schedule_notrace+0xd1/0x110 kernel/sched/core.c:7040 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:737 rcu_read_lock include/linux/rcupdate.h:842 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x10c/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:udevd state:R running task stack:23000 pid:5193 tgid:5193 ppid:1 task_flags:0x400140 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090 irqentry_exit+0x6f/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:fast_dput+0x2e/0x430 fs/dcache.c:817 Code: 56 41 55 41 54 53 49 89 fe e8 fe a6 87 ff 49 8d 9e b8 00 00 00 48 89 df e8 0f d0 7c 02 89 c5 31 ff 89 c6 e8 24 ab 87 ff 85 ed <0f> 88 97 00 00 00 31 ff 89 ee e8 13 ab 87 ff 85 ed 74 07 e8 ca a6 RSP: 0018:ffffc900037a7728 EFLAGS: 00000286 RAX: ffffffff82384b0c RBX: ffff8880248f4c78 RCX: 0000000000000000 RDX: ffff88807bff8000 RSI: 00000000ffffffff RDI: 0000000000000000 RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff82384857 R12: 1ffff920006f4f00 R13: ffff888078054a48 R14: ffff8880248f4bc0 R15: dffffc0000000000 dput+0xe8/0x2b0 fs/dcache.c:896 step_into+0x34d/0xf30 fs/namei.c:1991 walk_component fs/namei.c:2144 [inline] link_path_walk+0x756/0xe50 fs/namei.c:2503 path_openat+0x28c/0x3830 fs/namei.c:4035 do_filp_open+0x1fa/0x410 fs/namei.c:4066 do_sys_openat2+0x121/0x1c0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb99804dc3a RSP: 002b:00007ffe246af348 EFLAGS: 00000206 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000055d802a3a530 RCX: 00007fb99804dc3a RDX: 0000000000090800 RSI: 000055d8029fd3a0 RDI: 00000000ffffff9c RBP: 000055d8029fd3a0 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000206 R12: 000055d802a0e780 R13: 00000000000000fd R14: 000055d7f03c3be0 R15: 00007ffe246af660 rcu: rcu_preempt kthread starved for 10495 jiffies! g17789 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2046 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153 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: 5832 Comm: syz-executor Not tainted 6.15.0-rc6-syzkaller-00052-g9f35e33144ae #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xe6e/0x11c0 kernel/smp.c:885 Code: 89 ee 83 e6 01 31 ff e8 80 6d 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 2b 69 0b 00 eb 37 f3 90 43 0f b6 04 2c <84> c0 75 10 41 f7 07 01 00 00 00 74 1e e8 10 69 0b 00 eb e5 44 89 RSP: 0018:ffffc90003e075c0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b893ad40 RCX: ffff88801e349e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003e07720 R08: ffffffff8f7efb77 R09: 1ffffffff1efdf6e R10: dffffc0000000000 R11: fffffbfff1efdf6f R12: 1ffff11017108245 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8841228 FS: 00005555638a5500(0000) GS:ffff8881261c7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c38a0d8 CR3: 000000005d065000 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:1291 [inline] flush_tlb_mm_range+0x6ae/0x12b0 arch/x86/mm/tlb.c:1381 dup_mmap kernel/fork.c:765 [inline] dup_mm kernel/fork.c:1734 [inline] copy_mm+0x1882/0x2100 kernel/fork.c:1786 copy_process+0x16d3/0x3b80 kernel/fork.c:2429 kernel_clone+0x21e/0x870 kernel/fork.c:2844 __do_sys_clone kernel/fork.c:2987 [inline] __se_sys_clone kernel/fork.c:2971 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2971 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3ab09851d3 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:00007ffcf0043678 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3ab09851d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 00005555638a57d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 000000000002c9fc R15: 00007ffcf0043810