rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6199/1:b..l P1261/1:b..l P13/1:b..l rcu: (detected by 0, t=10506 jiffies, g=26989, q=690 ncpus=2) task:kworker/u8:1 state:R running task stack:20304 pid:13 tgid:13 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5521 [inline] __schedule+0x1b57/0x5bc0 kernel/sched/core.c:7272 preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7594 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x910 kernel/entry/common.c:167 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:679 RIP: 0010:lock_acquire+0x232/0x350 kernel/locking/lockdep.c:5913 Code: ff ff ff e8 40 c0 4a 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 92 1b 16 12 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 37 99 fb RSP: 0018:ffffc900001269e0 EFLAGS: 00000292 RAX: 9e0fe99c99b91500 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 0000000011bd6594 RSI: ffffffff8e80fd1e RDI: ffffffff8c6edc80 RBP: ffff88801dafddc0 R08: a700000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8ef5ca60 R12: ffffffff8ef5ca60 R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:309 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] class_rcu_constructor include/linux/rcupdate.h:1216 [inline] unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 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:5414 [inline] __kmalloc_noprof+0x36b/0x720 mm/slub.c:5439 _kmalloc_noprof include/linux/slab.h:995 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] cfg80211_inform_single_bss_data+0x990/0x1be0 net/wireless/scan.c:2382 cfg80211_inform_bss_data+0x263/0x3cc0 net/wireless/scan.c:3266 cfg80211_inform_bss_frame_data+0x3c7/0x840 net/wireless/scan.c:3358 ieee80211_bss_info_update+0x791/0xa50 net/mac80211/scan.c:230 ieee80211_rx_bss_info net/mac80211/ibss.c:1065 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1546 [inline] ieee80211_ibss_rx_queued_mgmt+0x1ce3/0x2c40 net/mac80211/ibss.c:1573 ieee80211_iface_process_skb net/mac80211/iface.c:1769 [inline] ieee80211_iface_work+0x78a/0x1010 net/mac80211/iface.c:1823 cfg80211_wiphy_work+0x29e/0x420 net/wireless/core.c:541 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:kworker/u8:9 state:R running task stack:24120 pid:1261 tgid:1261 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5521 [inline] __schedule+0x1b57/0x5bc0 kernel/sched/core.c:7272 preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7594 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x910 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:229 [inline] RIP: 0010:unwind_next_frame+0x205/0x2550 arch/x86/kernel/unwind_orc.c:510 Code: 6c 04 00 00 44 89 f8 4c 8d 2c 85 50 81 e5 91 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 4c 89 e3 0f 85 66 1d 00 00 45 8b 6d 00 <44> 89 f8 ff c0 4c 8d 24 85 50 81 e5 91 4c 89 e0 48 c1 e8 03 0f b6 RSP: 0018:ffffc900058bf560 EFLAGS: 00000246 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 8000000000000000 RDX: 00000000000af1fc RSI: ffffffff8c6edc60 RDI: ffffffff8c6edc20 RBP: ffffffff82376e5d R08: f200000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8ef5ca60 R12: dffffc0000000000 R13: 000000000003ea21 R14: ffffc900058bf608 R15: 000000000001376e arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 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+0x40/0x50 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:2748 [inline] slab_free mm/slub.c:6499 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6626 ieee80211_iface_work+0x259/0x1010 net/mac80211/iface.c:1825 cfg80211_wiphy_work+0x29e/0x420 net/wireless/core.c:541 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:syz-executor state:R running task stack:22384 pid:6199 tgid:6199 ppid:6196 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5521 [inline] __schedule+0x1b57/0x5bc0 kernel/sched/core.c:7272 preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7594 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x910 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x232/0x350 kernel/locking/lockdep.c:5913 Code: ff ff ff e8 40 c0 4a 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 92 1b 16 12 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 37 99 fb RSP: 0018:ffffc90003527860 EFLAGS: 00000296 RAX: 2b10411694b08500 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 00000000105209fd RSI: ffffffff8e80fd1e RDI: ffffffff8c6edc80 RBP: ffff88802f1f9f40 R08: 6f00000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8ef5ca60 R12: ffffffff8ef5ca60 R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:309 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] class_rcu_constructor include/linux/rcupdate.h:1216 [inline] unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 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+0x40/0x50 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:2748 [inline] slab_free mm/slub.c:6499 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6626 seq_release+0x63/0x70 fs/seq_file.c:357 kernfs_fop_release+0x2f8/0x440 fs/kernfs/file.c:777 __fput+0x418/0xa50 fs/file_table.c:512 fput_close_sync+0x11f/0x240 fs/file_table.c:617 __do_sys_close fs/open.c:1560 [inline] __se_sys_close fs/open.c:1545 [inline] __x64_sys_close+0x7e/0x110 fs/open.c:1545 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0d9d75b7ce RSP: 002b:00007fff87261408 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 000055557c748500 RCX: 00007f0d9d75b7ce RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fff87261a00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 R13: 00007fff87261490 R14: 00007fff872619c0 R15: 00007fff87261a00 rcu: rcu_preempt kthread starved for 10632 jiffies! g26989 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27656 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5521 [inline] __schedule+0x1b57/0x5bc0 kernel/sched/core.c:7272 __schedule_loop kernel/sched/core.c:7349 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7364 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: 6526 Comm: vhost-6524 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x80 kernel/kcov.c:206 Code: 89 fb e8 23 00 00 00 48 8b 3d f4 cf bd 0c 48 89 de 5b e9 b3 44 64 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0d 88 7f f1 11 65 48 8b 15 88 7f RSP: 0018:ffffc90003bb7478 EFLAGS: 00000a06 RAX: f3f3f3f8f1f1f1f1 RBX: ffff88807875e600 RCX: ffff888027a98000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88807875e600 RBP: ffffc90003bb7520 R08: ffffc90003bb7a00 R09: ffffc90003bb78d8 R10: dffffc0000000000 R11: ffffed100f0ebe19 R12: dffffc0000000000 R13: 1ffff92000776e90 R14: 0000000000000000 R15: 0000000000000000 FS: 00007ff840ec86c0(0000) GS:ffff88812488a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000002 CR3: 0000000036f52000 CR4: 00000000003526f0 Call Trace: find_vma+0x6b/0x160 mm/mmap.c:919 gup_vma_lookup mm/gup.c:1275 [inline] __get_user_pages+0x3bb/0x2750 mm/gup.c:1396 __get_user_pages_locked mm/gup.c:1692 [inline] __gup_longterm_locked+0xd52/0x15c0 mm/gup.c:2471 gup_fast_fallback+0x1d92/0x20e0 mm/gup.c:3209 set_bit_to_user drivers/vhost/vhost.c:2454 [inline] log_write+0xc2/0x3c0 drivers/vhost/vhost.c:2480 vhost_update_used_flags+0x1ed/0x2b0 drivers/vhost/vhost.c:2611 vhost_enable_notify+0xb7/0x640 drivers/vhost/vhost.c:3256 vhost_vsock_handle_tx_kick+0x2f0/0x10e0 drivers/vhost/vsock.c:556 vhost_run_work_list+0x14d/0x1e0 drivers/vhost/vhost.c:454 vhost_task_fn+0x2fc/0x4b0 kernel/vhost_task.c:49 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245