rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10187/1:b..l P5957/1:b..l rcu: (detected by 1, t=10502 jiffies, g=33521, q=2217500 ncpus=2) task:udevd state:R running task stack:21632 pid:5957 tgid:5957 ppid:5204 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5371 [inline] __schedule+0x189f/0x4c80 kernel/sched/core.c:6758 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7080 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5853 Code: 2b 00 74 08 4c 89 f7 e8 6a 21 8b 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:ffffc9000463f440 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920008c7e94 RCX: ffff888032cee4e0 RDX: dffffc0000000000 RSI: ffffffff8c0aa440 RDI: ffffffff8c5fbe80 RBP: ffffc9000463f598 R08: ffffffff942b2847 R09: 1ffffffff2856508 R10: dffffc0000000000 R11: fffffbfff2856509 R12: 1ffff920008c7e90 R13: dffffc0000000000 R14: ffffc9000463f4a0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] page_ext_get+0x3d/0x2a0 mm/page_ext.c:525 __reset_page_owner+0x30/0x430 mm/page_owner.c:290 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2658 discard_slab mm/slub.c:2673 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3142 put_cpu_partial+0x17c/0x250 mm/slub.c:3217 __slab_free+0x290/0x380 mm/slub.c:4468 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4104 [inline] slab_alloc_node mm/slub.c:4153 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4160 alloc_empty_file+0x9e/0x1d0 fs/file_table.c:228 path_openat+0x107/0x3590 fs/namei.c:3973 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1395 do_sys_open fs/open.c:1410 [inline] __do_sys_openat fs/open.c:1426 [inline] __se_sys_openat fs/open.c:1421 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1421 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: 0033:0x7ff0b358e9a4 RSP: 002b:00007ffc84c09820 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000055ff348f6a40 RCX: 00007ff0b358e9a4 RDX: 00000000000a0800 RSI: 000055ff348e8be0 RDI: 00000000ffffff9c RBP: 000055ff348e8be0 R08: 00000000ffffffff R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000a0800 R13: 000055ff348e7070 R14: 0000000000000001 R15: 000055ff348d6910 task:syz.0.731 state:R running task stack:24992 pid:10187 tgid:10186 ppid:5842 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5371 [inline] __schedule+0x189f/0x4c80 kernel/sched/core.c:6758 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7080 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:5853 Code: 2b 00 74 08 4c 89 f7 e8 6a 21 8b 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:ffffc90016aaf080 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92002d55e1c RCX: ffff88802dd10ae0 RDX: dffffc0000000000 RSI: ffffffff8c0aa440 RDI: ffffffff8c5fbe80 RBP: ffffc90016aaf1d8 R08: ffffffff942b2847 R09: 1ffffffff2856508 R10: dffffc0000000000 R11: fffffbfff2856509 R12: 1ffff92002d55e18 R13: dffffc0000000000 R14: ffffc90016aaf0e0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] page_ext_get+0x3d/0x2a0 mm/page_ext.c:525 __set_page_owner+0x9e/0x800 mm/page_owner.c:322 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1549 prep_new_page mm/page_alloc.c:1557 [inline] get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3475 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4752 alloc_pages_mpol+0x30e/0x550 mm/mempolicy.c:2270 folio_alloc_mpol_noprof+0x36/0x70 mm/mempolicy.c:2288 shmem_alloc_folio mm/shmem.c:1858 [inline] shmem_alloc_and_add_folio+0x4a0/0x1090 mm/shmem.c:1897 shmem_get_folio_gfp+0x621/0x1840 mm/shmem.c:2419 shmem_get_folio mm/shmem.c:2525 [inline] shmem_write_begin+0x165/0x350 mm/shmem.c:3181 generic_perform_write+0x346/0x990 mm/filemap.c:4036 shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3357 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xaeb/0xd30 fs/read_write.c:679 ksys_write+0x18f/0x2b0 fs/read_write.c:731 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: 0033:0x7f14f017e9cf RSP: 002b:00007f14f0f41e10 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f14f017e9cf RDX: 0000000001000000 RSI: 00007f14e5a00000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000005598 R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000003 R13: 00007f14f0f41f10 R14: 00007f14f0f41ed0 R15: 00007f14e5a00000 rcu: rcu_preempt kthread starved for 6517 jiffies! g33521 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:26104 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5371 [inline] __schedule+0x189f/0x4c80 kernel/sched/core.c:6758 __schedule_loop kernel/sched/core.c:6835 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6850 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.13.0-rc1-next-20241205-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:unwind_next_frame+0x18dc/0x22d0 arch/x86/kernel/unwind_orc.c:672 Code: 3d 3f 33 b8 0e 00 0f 84 9b 07 00 00 80 3d 65 ee e2 0c 01 75 40 80 3d a2 d0 cf 11 00 75 37 c6 05 99 d0 cf 11 01 e9 21 fa ff ff 01 00 00 00 e8 1a ab 21 00 65 8b 0d 8b 05 b8 7e b0 01 85 c9 75 RSP: 0018:ffffc90000155e90 EFLAGS: 00000206 RAX: ffffc90000158000 RBX: ffffc90000155fd0 RCX: ffffc90000155fc8 RDX: dffffc0000000000 RSI: ffffc90000150000 RDI: ffffc90000155fc8 RBP: ffffc90000155fc0 R08: ffffc90000155fb0 R09: 0000000000000000 R10: ffffc90000156010 R11: fffff5200002ac04 R12: dffffc0000000000 R13: ffffc90000155fc0 R14: ffffc90000150000 R15: ffffc90000155fc0 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3031fffc CR3: 000000002f096000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __unwind_start+0x59a/0x740 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe5/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __set_page_owner+0x92/0x800 mm/page_owner.c:320 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1549 prep_new_page mm/page_alloc.c:1557 [inline] get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3475 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4752 alloc_pages_mpol+0x30e/0x550 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2408 [inline] allocate_slab+0x8f/0x3a0 mm/slub.c:2574 new_slab mm/slub.c:2627 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3815 __slab_alloc+0x58/0xa0 mm/slub.c:3905 __slab_alloc_node mm/slub.c:3980 [inline] slab_alloc_node mm/slub.c:4141 [inline] kmem_cache_alloc_noprof+0x268/0x380 mm/slub.c:4160 dst_alloc+0x12b/0x190 net/core/dst.c:89 rt_dst_alloc net/ipv4/route.c:1625 [inline] __mkroute_output net/ipv4/route.c:2617 [inline] ip_route_output_key_hash_rcu+0x13cc/0x2390 net/ipv4/route.c:2839 ip_route_output_key_hash+0x193/0x2b0 net/ipv4/route.c:2668 __ip_route_output_key include/net/route.h:141 [inline] ip_route_output_flow+0x29/0x140 net/ipv4/route.c:2896 ip_route_output_key include/net/route.h:151 [inline] ip_route_me_harder+0x877/0x1360 net/ipv4/netfilter.c:53 synproxy_send_tcp+0x356/0x6c0 net/netfilter/nf_synproxy_core.c:431 synproxy_send_client_synack+0x8a4/0xe20 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4+0x3ca/0x610 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x362/0xa60 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161 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 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5672 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5785 process_backlog+0x662/0x15b0 net/core/dev.c:6117 __napi_poll+0xcb/0x490 net/core/dev.c:6883 napi_poll net/core/dev.c:6952 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7074 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 run_ksoftirqd+0xca/0x130 kernel/softirq.c:950 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