rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5501/1:b..l P974/1:b..l P5190/1:b..l P20412/2:b..l rcu: (detected by 1, t=10503 jiffies, g=118553, q=132 ncpus=2) task:syz.5.3845 state:R running task stack:23896 pid:20412 tgid:20410 ppid:9317 task_flags:0x40044c flags:0x20004006 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7087 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:page_ref_add_unless include/linux/page_ref.h:237 [inline] RIP: 0010:folio_ref_add_unless include/linux/page_ref.h:248 [inline] RIP: 0010:folio_try_get+0xf6/0x350 include/linux/page_ref.h:264 Code: ff 49 83 c7 34 4c 89 ff be 04 00 00 00 e8 c2 5c 2e 00 4c 89 fd 48 c1 ed 03 42 0f b6 44 25 00 84 c0 0f 85 50 01 00 00 41 8b 1f <31> ff 89 de e8 31 24 c7 ff 85 db 0f 84 8c 00 00 00 4c 89 ff be 04 RSP: 0018:ffffc90004ed7088 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81fa9dee RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffea0001c643b4 RBP: 1ffffd400038c876 R08: ffffea0001c643b7 R09: 1ffffd400038c876 R10: dffffc0000000000 R11: fffff9400038c877 R12: dffffc0000000000 R13: fffffffffffffffe R14: ffffffff81fa9d2e R15: ffffea0001c643b4 find_get_entry mm/filemap.c:2029 [inline] find_lock_entries+0x2bf/0xbb0 mm/filemap.c:2119 shmem_undo_range+0x2d4/0x1820 mm/shmem.c:1094 shmem_truncate_range mm/shmem.c:1224 [inline] shmem_evict_inode+0x29b/0xa80 mm/shmem.c:1352 evict+0x4e8/0x9a0 fs/inode.c:796 __dentry_kill+0x20d/0x630 fs/dcache.c:643 dput+0x19f/0x2b0 fs/dcache.c:885 __fput+0x60b/0x9f0 fs/file_table.c:472 task_work_run+0x24f/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2a/0x28e0 kernel/exit.c:938 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x168c/0x1720 kernel/signal.c:3036 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 __do_fast_syscall_32+0xc4/0x110 arch/x86/entry/common.c:389 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7f17579 RSP: 002b:00000000f503655c EFLAGS: 00000206 ORIG_RAX: 00000000000000c0 RAX: 0000000080000000 RBX: 0000000080000000 RCX: 0000000000b36000 RDX: 0000000006ebbeee RSI: 0000000000008031 RDI: 00000000ffffffff RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 task:syslogd state:R running task stack:22848 pid:5190 tgid:5190 ppid:1 task_flags:0x400000 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6944 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6968 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 unwind_next_frame+0x18f8/0x22d0 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 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:2660 __slab_free+0x2c2/0x380 mm/slub.c:4520 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:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] __kmalloc_cache_noprof+0x1d9/0x390 mm/slub.c:4320 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] task_numa_work+0xad9/0x14b0 kernel/sched/fair.c:3405 task_work_run+0x24f/0x310 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f890f1dc9a4 RSP: 002b:00007ffe4b248690 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: 0000000000000003 RBX: 000055767d531910 RCX: 00007f890f1dc9a4 RDX: 0000000000000d41 RSI: 00007f890f37b443 RDI: 00000000ffffff9c RBP: 00007f890f37b443 R08: 0000000000000001 R09: 0000000000000000 R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000000d41 R13: 0000000067be6925 R14: 0000000000000003 R15: 000055767d531a60 task:kworker/0:2 state:R running task stack:20728 pid:974 tgid:974 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7087 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:seqcount_lockdep_reader_access+0x1e0/0x220 include/linux/seqlock.h:75 Code: f7 4d 85 ed 75 16 e8 5f f6 aa f7 eb 15 e8 58 f6 aa f7 e8 93 96 f1 01 4d 85 ed 74 ea e8 49 f6 aa f7 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00 RSP: 0018:ffffc900046af900 EFLAGS: 00000293 RAX: ffffffff8a16c7b7 RBX: 0000000000000000 RCX: ffff888026a6da00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900046af9b0 R08: ffffffff8a16c78d R09: 1ffffffff28a931c R10: dffffc0000000000 R11: fffffbfff28a931d R12: dffffc0000000000 R13: 0000000000000200 R14: 0000000000000046 R15: 1ffff920008d5f20 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:333 [inline] gc_worker+0x316/0x1400 net/netfilter/nf_conntrack_core.c:1534 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 task:dhcpcd state:R running task stack:21856 pid:5501 tgid:5501 ppid:1 task_flags:0x400140 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6944 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6968 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 unwind_next_frame+0x18f8/0x22d0 arch/x86/kernel/unwind_orc.c:672 __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 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 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:2660 discard_slab mm/slub.c:2684 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3153 put_cpu_partial+0x17c/0x250 mm/slub.c:3228 __slab_free+0x290/0x380 mm/slub.c:4479 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_kmalloc+0x23/0xb0 mm/kasan/common.c:385 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4294 [inline] __kmalloc_node_track_caller_noprof+0x28b/0x4c0 mm/slub.c:4313 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:537 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:606 alloc_skb include/linux/skbuff.h:1331 [inline] alloc_skb_with_frags+0xc3/0x820 net/core/skbuff.c:6522 sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2897 unix_dgram_sendmsg+0x5e8/0x1df0 net/unix/af_unix.c:2017 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:733 sock_write_iter+0x2d7/0x3f0 net/socket.c:1137 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xacf/0xd10 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: 0033:0x7fcbef018bf2 RSP: 002b:00007fff9d529f98 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000055e0f8710d40 RCX: 00007fcbef018bf2 RDX: 0000000000000047 RSI: 00007fff9d529fb0 RDI: 0000000000000005 RBP: 00007fff9d529fb0 R08: 0000000000000008 R09: 0000000000000036 R10: 0000000000000000 R11: 0000000000000246 R12: 000055e0c6727efc R13: 00007fff9d52a3e0 R14: 000055e0f86e8d80 R15: 0000000000000001 rcu: rcu_preempt kthread starved for 5477 jiffies! g118553 f0x0 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:25520 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 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: 3398 Comm: kworker/R-bat_e Not tainted 6.14.0-rc4-syzkaller-00015-g2a1944bff549 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: bat_events batadv_tt_purge RIP: 0010:lockdep_hardirqs_on_prepare+0x12d/0x780 kernel/locking/lockdep.c:4389 Code: c7 44 24 40 00 00 00 00 9c 8f 44 24 40 80 3c 13 00 74 12 4c 89 f7 e8 62 84 8c 00 48 ba 00 00 00 00 00 fc ff df f6 44 24 41 02 <0f> 85 8a 03 00 00 48 c7 c0 80 09 65 9a 48 c1 e8 03 0f b6 04 10 84 RSP: 0018:ffffc90000006f60 EFLAGS: 00000046 RAX: 0000000000000004 RBX: 1ffff92000000df4 RCX: ffffffff9a650903 RDX: dffffc0000000000 RSI: ffffffff8c80eee0 RDI: ffffffff8c80eea0 RBP: ffffc90000007008 R08: ffffffff903cec77 R09: 1ffffffff2079d8e R10: dffffc0000000000 R11: fffffbfff2079d8f R12: ffffea0001edaf00 R13: ffff88807b6bc000 R14: ffffc90000006fa0 R15: 1ffff92000000df0 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000f750ed1c CR3: 0000000027f66000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:78 kasan_quarantine_put+0xdc/0x230 mm/kasan/quarantine.c:234 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4609 [inline] kmem_cache_free+0x195/0x410 mm/slub.c:4711 skb_kfree_head net/core/skbuff.c:994 [inline] skb_free_head net/core/skbuff.c:1008 [inline] skb_release_data+0x677/0x8a0 net/core/skbuff.c:1035 skb_release_all net/core/skbuff.c:1100 [inline] __kfree_skb net/core/skbuff.c:1114 [inline] consume_skb+0x9f/0xf0 net/core/skbuff.c:1346 nft_synproxy_eval_v4+0x3d2/0x610 net/netfilter/nft_synproxy.c:60 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:5899 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:6012 process_backlog+0x662/0x15b0 net/core/dev.c:6360 __napi_poll+0xcb/0x490 net/core/dev.c:7194 napi_poll net/core/dev.c:7263 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7385 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 do_softirq+0x11b/0x1e0 kernel/softirq.c:462 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:389 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_local_purge+0x2a0/0x340 net/batman-adv/translation-table.c:1315 batadv_tt_purge+0x35/0xa40 net/batman-adv/translation-table.c:3509 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317 rescuer_thread+0x650/0xf90 kernel/workqueue.c:3494 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244