rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=7e2c/1/0x4000000000000000 softirq=35280/35281 fqs=2 rcu: (detected by 1, t=10502 jiffies, g=28125, q=119 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5497 Comm: dhcpcd Not tainted 6.16.0-rc5-syzkaller-00224-g379f604cc3dc #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:86 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x146/0x1b0 mm/kasan/generic.c:189 Code: 83 c0 01 49 89 d3 48 39 d0 74 11 80 38 00 74 ef 4d 8d 1c 2c 48 89 c2 48 85 c0 75 ad 48 89 da 4c 89 d8 4c 29 da e9 46 ff ff ff <48> 85 d2 74 18 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 0a 80 38 00 RSP: 0018:ffffc90000007cd8 EFLAGS: 00000083 RAX: fffff52000000fa4 RBX: fffff52000000fa5 RCX: ffffffff8198d8bc RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000007d20 RBP: fffff52000000fa4 R08: 0000000000000001 R09: fffff52000000fa4 R10: ffffc90000007d23 R11: 0000000000000001 R12: ffff8880316002f0 R13: ffff8880316002f8 R14: ffff888031600340 R15: ffffffff899adeb0 FS: 00007f77fb6a6740(0000) GS:ffff888124713000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c315faa CR3: 000000007598b000 CR4: 00000000003526f0 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1301 [inline] queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] do_raw_spin_lock+0x12c/0x2b0 kernel/locking/spinlock_debug.c:116 spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xd9/0xc80 net/sched/sch_taprio.c:924 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x202/0xad0 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:slab_update_freelist mm/slub.c:728 [inline] RIP: 0010:__slab_free+0xbc/0x500 mm/slub.c:4495 Code: 44 89 7c 24 68 66 45 85 ff 74 07 45 31 f6 84 c0 74 0e 45 31 f6 80 7c 24 38 00 0f 84 0c 01 00 00 48 8b 44 24 30 48 8b 4c 24 68 40 0a 20 74 64 4c 89 e0 48 8b 5c 24 08 f0 49 0f c7 4d 20 0f 94 RSP: 0018:ffffc9000479f7a0 EFLAGS: 00000246 RAX: ffff88801ce8e280 RBX: ffff88801ce8e280 RCX: 000000000024001f RDX: 0000000000240020 RSI: ffff8880583740e0 RDI: ffffc9000479f820 RBP: ffffc9000479f850 R08: 0000000000000001 R09: ffffffff8222e5a8 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888058374150 R13: ffffea000160dd00 R14: 0000000000000000 R15: 000000000024001f qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_node_noprof+0x1d5/0x3b0 mm/slub.c:4249 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1336 [inline] alloc_skb_with_frags+0xe0/0x860 net/core/skbuff.c:6665 sock_alloc_send_pskb+0x7fb/0x990 net/core/sock.c:2999 unix_dgram_sendmsg+0x41a/0x1840 net/unix/af_unix.c:2083 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] __sys_sendto+0x4a0/0x520 net/socket.c:2180 __do_sys_sendto net/socket.c:2187 [inline] __se_sys_sendto net/socket.c:2183 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2183 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f77fb730407 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:00007ffce006efd0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f77fb6a6740 RCX: 00007f77fb730407 RDX: 000000000000003f RSI: 00007ffce006f110 RDI: 0000000000000003 RBP: 00007ffce006f540 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffce006f990 R13: 00007ffce006f110 R14: 000000000000001d R15: 00007ffce006f110 rcu: rcu_preempt kthread starved for 10498 jiffies! g28125 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6790 __schedule_loop kernel/sched/core.c:6868 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6883 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 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: 1101 Comm: kworker/u8:6 Not tainted 6.16.0-rc5-syzkaller-00224-g379f604cc3dc #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xd7b/0x1510 kernel/smp.c:885 Code: e8 6a 19 0c 00 45 85 ed 74 46 48 8b 14 24 49 89 d6 49 89 d5 49 c1 ee 03 41 83 e5 07 4d 01 e6 41 83 c5 03 e8 07 1e 0c 00 f3 90 <41> 0f b6 06 41 38 c5 7c 08 84 c0 0f 85 6f 05 00 00 8b 43 08 31 ff RSP: 0018:ffffc90003c8f8a0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b84421e0 RCX: ffffffff81afd92d RDX: ffff8880281c0000 RSI: ffffffff81afd909 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000 R13: 0000000000000003 R14: ffffed101708843d R15: ffff8880b853b580 FS: 0000000000000000(0000) GS:ffff888124813000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000021a030 CR3: 000000000e382000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2691 [inline] smp_text_poke_batch_finish+0x27b/0xdb0 arch/x86/kernel/alternative.c:2901 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x376/0x550 kernel/jump_label.c:919 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate mm/kfence/core.c:850 [inline] toggle_allocation_gate+0xfa/0x280 mm/kfence/core.c:842 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245