rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5444/1:b..l rcu: (detected by 0, t=10503 jiffies, g=6545, q=2652627 ncpus=2) task:syz.0.35 state:R running task stack:23168 pid:5444 tgid:5442 ppid:5227 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6997 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5829 Code: 2b 00 74 08 4c 89 f7 e8 aa 46 8e 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90008be6f40 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200117cdf4 RCX: 3adf4414babd8e00 RDX: dffffc0000000000 RSI: ffffffff8c0adc40 RDI: ffffffff8c60f860 RBP: ffffc90008be7088 R08: ffffffff942c5807 R09: 1ffffffff2858b00 R10: dffffc0000000000 R11: fffffbfff2858b01 R12: 1ffff9200117cdf0 R13: dffffc0000000000 R14: ffffc90008be6fa0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] __pte_offset_map+0x9e/0x380 mm/pgtable-generic.c:287 __pte_offset_map_lock+0xc7/0x300 mm/pgtable-generic.c:371 pte_offset_map_lock include/linux/mm.h:3014 [inline] finish_fault+0x79d/0x1480 mm/memory.c:5129 do_read_fault mm/memory.c:5286 [inline] do_fault mm/memory.c:5416 [inline] do_pte_missing mm/memory.c:3965 [inline] handle_pte_fault+0x2d44/0x6800 mm/memory.c:5751 __handle_mm_fault mm/memory.c:5894 [inline] handle_mm_fault+0x1106/0x1bb0 mm/memory.c:6062 faultin_page mm/gup.c:1187 [inline] __get_user_pages+0x1b16/0x48d0 mm/gup.c:1485 populate_vma_page_range+0x264/0x330 mm/gup.c:1923 __mm_populate+0x27a/0x460 mm/gup.c:2026 mm_populate include/linux/mm.h:3371 [inline] vm_mmap_pgoff+0x2c3/0x3d0 mm/util.c:593 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8ce4d7dff9 RSP: 002b:00007f8ce5b8c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f8ce4f36058 RCX: 00007f8ce4d7dff9 RDX: 0000000000000003 RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 00007f8ce4df0296 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f8ce4f36058 R15: 00007ffe54ade278 rcu: rcu_preempt kthread starved for 6795 jiffies! g6545 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:24912 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-rc1-syzkaller-00238-g8b641b5e4c78 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:unwind_next_frame+0x5/0x22d0 arch/x86/kernel/unwind_orc.c:469 Code: 80 e1 07 80 c1 03 38 c1 7c 91 4c 89 f7 e8 a3 36 bd 00 eb 87 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 <41> 57 41 56 41 55 41 54 53 48 81 ec 98 00 00 00 49 89 fd 49 bc 00 RSP: 0018:ffffc90000156a70 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffc90000156a80 RCX: ffffffff917b9000 RDX: dffffc0000000000 RSI: ffffffff89dc921d RDI: ffffc90000156a80 RBP: ffffc90000156b10 R08: 0000000000000007 R09: ffffc90000156b70 R10: ffffc90000156ad0 R11: ffffffff81808f50 R12: ffff88801ceb5a00 R13: ffffffff81808f50 R14: ffffc90000156b60 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9e4bdd8d58 CR3: 0000000063ea4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4142 fill_pool lib/debugobjects.c:168 [inline] debug_objects_fill_pool+0x4cf/0x9f0 lib/debugobjects.c:615 debug_object_activate+0x135/0x510 lib/debugobjects.c:704 debug_rcu_head_queue kernel/rcu/rcu.h:224 [inline] __call_rcu_common kernel/rcu/tree.c:3071 [inline] call_rcu+0x97/0xa70 kernel/rcu/tree.c:3190 slab_free_hook mm/slub.c:2307 [inline] slab_free mm/slub.c:4580 [inline] kmem_cache_free+0x2fc/0x420 mm/slub.c:4682 nf_conntrack_free+0x2fd/0x390 net/netfilter/nf_conntrack_core.c:1735 nf_ct_put include/net/netfilter/nf_conntrack.h:186 [inline] nf_conntrack_in+0xb51/0x1890 net/netfilter/nf_conntrack_core.c:2061 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 __netif_receive_skb_one_core net/core/dev.c:5666 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5779 process_backlog+0x662/0x15b0 net/core/dev.c:6111 __napi_poll+0xcb/0x490 net/core/dev.c:6775 napi_poll net/core/dev.c:6844 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6966 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:927 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244