rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P145/1:b..l P13465/1:b..l P7368/1:b..l P135/1:b..l rcu: (detected by 0, t=10503 jiffies, g=85853, q=338 ncpus=2) task:kworker/u8:6 state:R running task stack:22568 pid:135 tgid:135 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5030 kernel/sched/core.c:6864 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7191 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_acquire+0x16c/0x350 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 c9 d7 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90002ea6978 EFLAGS: 00000206 RAX: 81bb2a7b3e441000 RBX: 0000000000000000 RCX: 81bb2a7b3e441000 RDX: 0000000000000000 RSI: ffffffff8d9760ce RDI: ffffffff8bbf81e0 RBP: ffffffff81745035 R08: 0000000000000000 R09: ffffffff81745035 R10: ffffc90002ea6b38 R11: ffffffff81adcc20 R12: 0000000000000002 R13: ffffffff8df3d980 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:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5652 [inline] __kmalloc_noprof+0x41d/0x800 mm/slub.c:5664 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] cfg80211_inform_single_bss_data+0x8dc/0x1aa0 net/wireless/scan.c:2345 cfg80211_inform_bss_data+0x203/0x3b40 net/wireless/scan.c:3228 cfg80211_inform_bss_frame_data+0x3c7/0x730 net/wireless/scan.c:3319 ieee80211_bss_info_update+0x749/0x9e0 net/mac80211/scan.c:230 ieee80211_rx_bss_info net/mac80211/ibss.c:1094 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1575 [inline] ieee80211_ibss_rx_queued_mgmt+0xa5d/0x2b10 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/0x470 net/wireless/core.c:438 process_one_work+0x93a/0x15e0 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:udevd state:R running task stack:23136 pid:7368 tgid:7368 ppid:5201 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5030 kernel/sched/core.c:6864 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7048 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7072 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] fast_dput+0x233/0x430 fs/dcache.c:-1 dput+0xe8/0x1a0 fs/dcache.c:924 path_put+0x39/0x60 fs/namei.c:665 vfs_statx+0x36e/0x550 fs/stat.c:357 vfs_fstatat+0x118/0x170 fs/stat.c:375 __do_sys_newfstatat fs/stat.c:542 [inline] __se_sys_newfstatat fs/stat.c:536 [inline] __x64_sys_newfstatat+0x116/0x190 fs/stat.c:536 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f53e1311b0a RSP: 002b:00007ffc2ee75858 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f53e1311b0a RDX: 00007ffc2ee75860 RSI: 00007ffc2ee75930 RDI: 00000000ffffff9c RBP: 00007ffc2ee76970 R08: 0000000000000075 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc2ee77350 R13: 0000000000000000 R14: 00005597237ca6d7 R15: 000055974d0db640 task:syz.0.1561 state:R running task stack:26888 pid:13465 tgid:13465 ppid:12222 task_flags:0x40044c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5030 kernel/sched/core.c:6864 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7048 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7072 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1882 [inline] zap_pmd_range mm/memory.c:1944 [inline] zap_pud_range mm/memory.c:1973 [inline] zap_p4d_range mm/memory.c:1994 [inline] unmap_page_range+0x38bc/0x4170 mm/memory.c:2015 unmap_single_vma mm/memory.c:2057 [inline] unmap_vmas+0x399/0x580 mm/memory.c:2099 exit_mmap+0x239/0xb40 mm/mmap.c:1277 __mmput+0x118/0x430 kernel/fork.c:1173 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x658/0x2310 kernel/exit.c:959 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2e9/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f08ceb8f749 RSP: 002b:00007ffecc11be48 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000000 RBX: 00000000000be713 RCX: 00007f08ceb8f749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f08cede5fac RBP: 0000000000000032 R08: 3fffffffffffffff R09: 00000001cc11c13f R10: 00007ffecc11bf40 R11: 0000000000000246 R12: 00007f08cede5fac R13: 00007ffecc11bf40 R14: 00000000000be745 R15: 00007ffecc11bf60 task:kworker/u8:7 state:R running task stack:21976 pid:145 tgid:145 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5030 kernel/sched/core.c:6864 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7191 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:arch_static_branch arch/x86/include/asm/jump_label.h:37 [inline] RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline] RIP: 0010:lock_acquire+0x39/0x350 kernel/locking/lockdep.c:5831 Code: 83 ec 60 4d 89 ce 45 89 c7 41 89 cc 89 54 24 04 89 f3 49 89 fd 48 8b ac 24 98 00 00 00 65 48 8b 05 4c ca d7 10 48 89 44 24 58 <0f> 1f 44 00 00 65 8b 05 4f ca d7 10 83 f8 08 0f 83 af 01 00 00 89 RSP: 0018:ffffc90002e77138 EFLAGS: 00000282 RAX: 57d267eb521a3100 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8df3d980 RBP: ffffffff81745035 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90002e772f8 R11: ffffffff81adcc20 R12: 0000000000000002 R13: ffffffff8df3d980 R14: 0000000000000000 R15: 0000000000000000 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:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6663 [inline] kfree+0x1c0/0x680 mm/slub.c:6871 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1576 [inline] ieee80211_ibss_rx_queued_mgmt+0x1206/0x2b10 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/0x470 net/wireless/core.c:438 process_one_work+0x93a/0x15e0 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 10651 jiffies! g85853 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:27168 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5030 kernel/sched/core.c:6864 __schedule_loop kernel/sched/core.c:6946 [inline] schedule+0x165/0x360 kernel/sched/core.c:6961 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 13459 Comm: syz.4.1557 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x83/0x90 kernel/kcov.c:316 Code: 8d 52 28 4d 39 ca 77 22 89 ff 89 f6 49 ff c0 4c 89 01 48 c7 44 11 08 05 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 cc cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc9000c127aa0 EFLAGS: 00000097 RAX: ffffffff81b34ecf RBX: 000000cec4783687 RCX: 0000000000000002 RDX: ffff8880305f8000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffff88823bf3412f R09: 0000000000000000 R10: ffff88823bf34118 R11: ffffed10477e6826 R12: 7fffffffffffffff R13: dffffc0000000000 R14: ffff8880b8723e40 R15: 0000000000000003 FS: 00007f68d5df66c0(0000) GS:ffff888125fba000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3362488fe8 CR3: 00000000453bc000 CR4: 00000000003526f0 Call Trace: tick_program_event+0x8f/0x120 kernel/time/tick-oneshot.c:48 hrtimer_start_range_ns+0xd8a/0x1080 kernel/time/hrtimer.c:1323 __posixtimer_deliver_signal kernel/time/posix-timers.c:321 [inline] posixtimer_deliver_signal+0x1cf/0x410 kernel/time/posix-timers.c:347 dequeue_signal+0x24a/0x370 kernel/signal.c:660 get_signal+0x55e/0x1340 kernel/signal.c:2914 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2e9/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f68d7b8f747 Code: ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 <0f> 05 48 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 RSP: 002b:00007f68d5df6038 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 00007f68d7de5fa0 RCX: 00007f68d7b8f749 RDX: 0000000000000005 RSI: 0000200000000100 RDI: 0000000000000004 RBP: 00007f68d7c13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f68d7de6038 R14: 00007f68d7de5fa0 R15: 00007ffda0e9aef8