rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P17706/1:b..l P17701/1:b..l rcu: (detected by 0, t=10502 jiffies, g=109777, q=880 ncpus=2) task:syz.1.2998 state:R running task stack:24968 pid:17701 tgid:17699 ppid:17463 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 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 3b bd fe 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90004aae8f8 EFLAGS: 00000206 RAX: 03da78adabdfed00 RBX: 0000000000000000 RCX: 03da78adabdfed00 RDX: 0000000000000000 RSI: ffffffff8db6ec2e RDI: ffffffff8be28ac0 RBP: ffffffff81729af5 R08: 0000000000000000 R09: ffffffff81729af5 R10: ffffc90004aaeab8 R11: ffffffff81acf6c0 R12: 0000000000000002 R13: ffffffff8e13eda0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 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:156 __set_page_owner+0x8d/0x4a0 mm/page_owner.c:329 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 folio_alloc_mpol_noprof mm/mempolicy.c:2438 [inline] vma_alloc_folio_noprof+0xe4/0x200 mm/mempolicy.c:2473 folio_prealloc+0x30/0x180 mm/memory.c:-1 wp_page_copy mm/memory.c:3569 [inline] do_wp_page+0x1231/0x5800 mm/memory.c:4030 handle_pte_fault mm/memory.c:6105 [inline] __handle_mm_fault+0x1144/0x5620 mm/memory.c:6232 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6401 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1387 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: 0010:__put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:104 Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca e9 d7 31 03 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 01 cb <89> 01 31 c9 0f 01 ca c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90004aaf8b8 EFLAGS: 00050202 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000200000103030 RDX: ffff88802c9abc00 RSI: 0000000000000002 RDI: 00000000ffffffff RBP: ffffc90004aafa30 R08: ffffc90004aaf667 R09: 1ffff92000955ecc R10: dffffc0000000000 R11: fffff52000955ecd R12: 0000000000000002 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000200000103000 ____sys_recvmsg+0x2ab/0x460 net/socket.c:2799 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2828 do_recvmmsg+0x307/0x770 net/socket.c:2923 __sys_recvmmsg net/socket.c:2997 [inline] __do_sys_recvmmsg net/socket.c:3020 [inline] __se_sys_recvmmsg net/socket.c:3013 [inline] __x64_sys_recvmmsg+0x190/0x240 net/socket.c:3013 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: 0033:0x7f1525d8e929 RSP: 002b:00007f1526b8a038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f1525fb6080 RCX: 00007f1525d8e929 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004 RBP: 00007f1525e10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f1525fb6080 R15: 00007f15260dfa28 task:sed state:R running task stack:24104 pid:17706 tgid:17706 ppid:17705 task_flags:0x40000c flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:latch_tree_find include/linux/rbtree_latch.h:210 [inline] RIP: 0010:bpf_ksym_find kernel/bpf/core.c:740 [inline] RIP: 0010:is_bpf_text_address+0xd6/0x2b0 kernel/bpf/core.c:773 Code: 01 48 c7 c7 a0 d9 90 8b be 4b 03 00 00 48 c7 c2 e0 d9 90 8b e8 6b 16 cf ff 49 bd 00 00 00 00 00 fc ff df 44 8b 25 6a cd 11 0c <44> 89 e3 83 e3 01 4c 8d 3c dd f0 13 e1 8d 4c 89 f8 48 c1 e8 03 42 RSP: 0018:ffffc90004b275d0 EFLAGS: 00000293 RAX: ffffffff81cf45ed RBX: 00007f96f47096c5 RCX: ffff8880460a0000 RDX: 0000000000000000 RSI: ffffffff8be28aa0 RDI: ffffffff8be28a60 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81cf45a6 R10: ffffc90004b276b8 R11: ffffffff81acf6c0 R12: 0000000000000004 R13: dffffc0000000000 R14: 00007f96f47096c5 R15: 1ffff92000964ed6 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+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4643 [inline] kmem_cache_free+0x2f6/0x400 mm/slub.c:4745 exit_mmap+0x53f/0xb50 mm/mmap.c:1309 __mmput+0x118/0x420 kernel/fork.c:1121 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x640/0x22e0 kernel/exit.c:943 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 __do_sys_exit_group kernel/exit.c:1115 [inline] __se_sys_exit_group kernel/exit.c:1113 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1113 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7f96f47096c5 RSP: 002b:00007ffcff555828 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f96f480afe8 RCX: 00007f96f47096c5 RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f96f4809680 R15: 00007f96f480b000 rcu: rcu_preempt kthread timer wakeup didn't happen for 10616 jiffies! g109777 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=54325 rcu: rcu_preempt kthread starved for 10617 jiffies! g109777 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 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:I stack:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 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+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 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: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.16.0-rc2-syzkaller-00318-g739a6c93cc75 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: mld mld_ifc_work RIP: 0010:find_entry_to_transmit+0x65b/0x8d0 net/sched/sch_taprio.c:380 Code: 24 40 80 3c 01 00 4c 8b 7c 24 30 4c 8b 6c 24 20 74 08 4c 89 ff e8 25 fc 9d f8 48 8b 44 24 28 48 8b 4c 24 10 48 01 c1 49 89 0f <4c> 8d 3c 03 b0 01 48 89 44 24 48 48 8b 6c 24 18 eb 7b e8 ee 7c 3a RSP: 0018:ffffc900000f6fd8 EFLAGS: 00000202 RAX: 0000000000008001 RBX: 184bbd2a2d1ea7f1 RCX: 184bbd2a2d1ea7f1 RDX: 0000000000000000 RSI: 184bbd2a2d1e53ee RDI: 184bbd2a2d1e27f0 RBP: 184bbd2a2d1e27f0 R08: ffff8880288772e7 R09: 1ffff1100510ee5c R10: dffffc0000000000 R11: ffffed100510ee5d R12: 184bbd2a2d1da701 R13: ffff888030048d40 R14: ffff888030048940 R15: ffffc900000f7170 FS: 0000000000000000(0000) GS:ffff888125c51000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555587dbe808 CR3: 000000005b284000 CR4: 00000000003526f0 Call Trace: get_packet_txtime net/sched/sch_taprio.c:497 [inline] taprio_enqueue_one+0xb66/0x1650 net/sched/sch_taprio.c:566 dev_qdisc_enqueue+0x4b/0x260 net/core/dev.c:4068 __dev_xmit_skb net/core/dev.c:4164 [inline] __dev_queue_xmit+0xe0e/0x3a70 net/core/dev.c:4679 neigh_output include/net/neighbour.h:539 [inline] ip6_finish_output2+0x11fb/0x16a0 net/ipv6/ip6_output.c:141 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:226 NF_HOOK+0x9e/0x380 include/linux/netfilter.h:317 mld_sendpack+0x800/0xd80 net/ipv6/mcast.c:1868 mld_send_cr net/ipv6/mcast.c:2169 [inline] mld_ifc_work+0x835/0xde0 net/ipv6/mcast.c:2702 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245