rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P212/2:b..l P1315/1:b..l P34/1:b..l P12/1:b..l P5198/1:b..l rcu: (detected by 0, t=10502 jiffies, g=15773, q=324 ncpus=2) task:udevd state:R running task stack:25160 pid:5198 tgid:5198 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2a6/0x3b0 kernel/locking/lockdep.c:5893 Code: 4d 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 52 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 fa 44 24 11 <48> 3b 44 24 28 75 75 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d c3 RSP: 0018:ffffc90003177850 EFLAGS: 00000206 RAX: cb4c9f17eb550300 RBX: 0000000000000202 RCX: cb4c9f17eb550300 RDX: 0000000000000000 RSI: ffffffff8dc8c9b6 RDI: ffffffff8be248e0 RBP: ffff888035a94830 R08: ffffc900031779e7 R09: 0000000000000000 R10: ffffc900031779d8 R11: fffff5200062ef3d R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8e3419e0 R15: ffff888035a93d00 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6668 [inline] kmem_cache_free+0x197/0x620 mm/slub.c:6779 file_free fs/file_table.c:71 [inline] __fput+0x6c2/0xa70 fs/file_table.c:481 fput_close_sync+0x113/0x220 fs/file_table.c:573 __do_sys_close fs/open.c:1573 [inline] __se_sys_close fs/open.c:1558 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1558 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f76e5115a67 RSP: 002b:00007ffe3acfb688 EFLAGS: 00000297 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000564611b3e730 RCX: 00007f76e5115a67 RDX: 00007f76e51efea0 RSI: 0000564611bccc60 RDI: 000000000000000c RBP: 00007f76e51efff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000 R13: 3d45505954564544 R14: 3d5845444e494649 R15: 3d454d414e564544 task:kworker/u8:0 state:R running task stack:24000 pid:12 tgid:12 ppid:2 task_flags:0x4208160 flags:0x00080000 Workqueue: events_unbound linkwatch_event Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x16c/0x340 kernel/locking/lockdep.c:5872 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 14 77 24 11 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc900001170b8 EFLAGS: 00000206 RAX: ff0fe53f874fc200 RBX: 0000000000000000 RCX: ff0fe53f874fc200 RDX: 00000000a47495a5 RSI: ffffffff8dc8c9b6 RDI: ffffffff8be248e0 RBP: ffffffff81747f85 R08: ffffffff81747f85 R09: ffffffff8e3419e0 R10: ffffc90000117278 R11: ffffffff81ade290 R12: 0000000000000002 R13: ffffffff8e3419e0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [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 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6668 [inline] kfree+0x1c0/0x660 mm/slub.c:6876 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1107 skb_release_all net/core/skbuff.c:1182 [inline] __kfree_skb net/core/skbuff.c:1196 [inline] consume_skb+0x9e/0xf0 net/core/skbuff.c:1428 netlink_broadcast_filtered+0xec7/0x1000 net/netlink/af_netlink.c:1535 nlmsg_multicast_filtered include/net/netlink.h:1165 [inline] nlmsg_multicast include/net/netlink.h:1184 [inline] nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2593 netif_state_change+0x289/0x380 net/core/dev.c:1586 linkwatch_do_dev+0x124/0x180 net/core/link_watch.c:186 __linkwatch_run_queue+0x56a/0x7e0 net/core/link_watch.c:244 linkwatch_event+0x4c/0x60 net/core/link_watch.c:304 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 task:kworker/u8:2 state:R running task stack:23864 pid:34 tgid:34 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:217 [inline] RIP: 0010:unwind_next_frame+0x214/0x2390 arch/x86/kernel/unwind_orc.c:494 Code: ef 08 8b 15 5e e2 57 0c 8d 42 ff 44 39 f8 0f 86 65 18 00 00 44 89 f8 4c 8d 2c 85 28 06 04 91 4c 89 e8 48 c1 e8 03 0f b6 04 28 <84> c0 48 89 eb 0f 85 1c 1c 00 00 45 8b 6d 00 44 89 f8 ff c0 48 8d RSP: 0018:ffffc90000aa6f98 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 6b422eee4ee70400 RDX: 00000000000a68ad RSI: ffffffff8be248c0 RDI: ffffffff8be24880 RBP: dffffc0000000000 R08: ffffffff81747f85 R09: ffffffff8e3419e0 R10: ffffc90000aa70b8 R11: ffffffff81ade290 R12: ffffffff8ab2da1a R13: ffffffff912ad190 R14: ffffc90000aa7068 R15: 000000000009b2da arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5657 [inline] __kmalloc_noprof+0x41d/0x800 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] ieee802_11_parse_elems_full+0x152/0x2ab0 net/mac80211/parse.c:1031 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2469 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1571 [inline] ieee80211_ibss_rx_queued_mgmt+0x48e/0x2af0 net/mac80211/ibss.c:1602 ieee80211_iface_process_skb net/mac80211/iface.c:1736 [inline] ieee80211_iface_work+0x85f/0x12d0 net/mac80211/iface.c:1790 cfg80211_wiphy_work+0x2ab/0x450 net/wireless/core.c:438 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 task:kworker/u8:10 state:R running task stack:22696 pid:1315 tgid:1315 ppid:2 task_flags:0x24248060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2a6/0x3b0 kernel/locking/lockdep.c:5893 Code: 4d 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 52 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 fa 44 24 11 <48> 3b 44 24 28 75 75 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d c3 RSP: 0018:ffffc900045de0d0 EFLAGS: 00000206 RAX: c8bb483edab66700 RBX: 0000000000000202 RCX: c8bb483edab66700 RDX: 0000000000000006 RSI: ffffffff8dc8c9b6 RDI: ffffffff8be248e0 RBP: ffff8880286ae7a0 R08: ffffc900045de610 R09: 0000000000000000 R10: ffffc900045de258 R11: fffff520008bbc4d R12: 0000000000000006 R13: 0000000000000006 R14: ffffffff8e3419e0 R15: ffff8880286adb80 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270 ext4_mb_new_blocks+0x546/0x46a0 fs/ext4/mballoc.c:6297 ext4_ext_map_blocks+0x18bd/0x6c80 fs/ext4/extents.c:4414 ext4_map_create_blocks fs/ext4/inode.c:613 [inline] ext4_map_blocks+0x82c/0x16f0 fs/ext4/inode.c:816 mpage_map_one_extent fs/ext4/inode.c:2380 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2474 [inline] ext4_do_writepages+0x222f/0x4500 fs/ext4/inode.c:2932 ext4_writepages+0x203/0x350 fs/ext4/inode.c:3026 do_writepages+0x32e/0x550 mm/page-writeback.c:2598 __writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737 writeback_sb_inodes+0x93a/0x1870 fs/fs-writeback.c:2030 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2107 wb_writeback+0x43f/0xaa0 fs/fs-writeback.c:2218 wb_check_old_data_flush fs/fs-writeback.c:2322 [inline] wb_do_writeback fs/fs-writeback.c:2375 [inline] wb_workfn+0xad2/0xed0 fs/fs-writeback.c:2403 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 task:kworker/u8:8 state:R running task stack:23112 pid:212 tgid:212 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 RIP: 0010:lock_is_held_type+0x137/0x190 kernel/locking/lockdep.c:5945 Code: 01 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 05 a9 4a 5e 07 <48> 3b 44 24 08 75 43 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc90002fb74f8 EFLAGS: 00000206 RAX: fd27794f6a8a9e00 RBX: 0000000000000001 RCX: fd27794f6a8a9e00 RDX: ffff88801eb08000 RSI: ffffffff8dc8c9b6 RDI: ffffffff8be248e0 RBP: 00000000ffffffff R08: ffffffff8ad2d62f R09: ffffffff8e3419e0 R10: dffffc0000000000 R11: fffff520005f6e80 R12: 0000000000000246 R13: ffff88801eb08000 R14: ffffffff8e3419e0 R15: 0000000000000003 lock_is_held include/linux/lockdep.h:249 [inline] rcu_read_lock_any_held+0x89/0x120 kernel/rcu/update.c:386 __rhashtable_lookup include/linux/rhashtable.h:626 [inline] rhltable_lookup include/linux/rhashtable.h:731 [inline] sta_info_hash_lookup+0x8a/0x610 net/mac80211/sta_info.c:199 sta_info_get+0xf4/0x300 net/mac80211/sta_info.c:211 ieee80211_update_sta_info net/mac80211/ibss.c:979 [inline] ieee80211_rx_bss_info net/mac80211/ibss.c:1092 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1575 [inline] ieee80211_ibss_rx_queued_mgmt+0x12d5/0x2af0 net/mac80211/ibss.c:1602 ieee80211_iface_process_skb net/mac80211/iface.c:1736 [inline] ieee80211_iface_work+0x85f/0x12d0 net/mac80211/iface.c:1790 cfg80211_wiphy_work+0x2ab/0x450 net/wireless/core.c:438 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: rcu_preempt kthread starved for 10722 jiffies! g15773 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 6092 Comm: vhost-6089 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__get_user_pages+0x267/0x29f0 mm/gup.c:1374 Code: b6 ff 31 ff 44 89 7c 24 58 44 89 fe e8 72 50 b6 ff 49 8d 8c 24 b8 00 00 00 48 8b 44 24 38 48 83 c0 18 48 89 84 24 e0 00 00 00 <48> c7 c0 14 d5 cb 8d 48 c1 e8 03 48 89 84 24 d0 00 00 00 48 c7 c0 RSP: 0018:ffffc900030774f0 EFLAGS: 00000286 RAX: ffffc90003077a18 RBX: 0000000000000015 RCX: ffff88801f34bdf8 RDX: ffff888011885b80 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffc90003077a00 R09: ffffc90003077898 R10: dffffc0000000000 R11: ffffed1003e698ed R12: ffff88801f34bd40 R13: 0000000000290001 R14: 00000000ffffffff R15: 0000000000000001 FS: 00007f29d91f66c0(0000) GS:ffff8881259ed000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3b930c7f98 CR3: 000000001e2e8000 CR4: 00000000003526f0 Call Trace: __get_user_pages_locked mm/gup.c:1692 [inline] __gup_longterm_locked+0xde4/0x1660 mm/gup.c:2476 gup_fast_fallback+0x1d6b/0x22d0 mm/gup.c:3220 set_bit_to_user drivers/vhost/vhost.c:2425 [inline] log_write+0xc3/0x390 drivers/vhost/vhost.c:2451 vhost_update_used_flags+0x1ed/0x2b0 drivers/vhost/vhost.c:2582 vhost_disable_notify+0xad/0x1e0 drivers/vhost/vhost.c:3263 vhost_vsock_handle_tx_kick+0x156/0xfe0 drivers/vhost/vsock.c:500 vhost_run_work_list+0x14e/0x1e0 drivers/vhost/vhost.c:454 vhost_task_fn+0x27c/0x430 kernel/vhost_task.c:49 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246