rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=a55c/1/0x4000000000000000 softirq=148864/148864 fqs=3 rcu: (detected by 1, t=10502 jiffies, g=156653, q=264 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 23895 Comm: syz.9.4817 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:_find_first_zero_bit+0x0/0xb0 lib/find_bit.c:148 Code: fc ff df 80 3c 08 00 74 86 e8 7c b1 76 fd e9 7c ff ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 57 41 56 41 55 41 54 53 48 85 f6 74 46 48 89 f3 49 RSP: 0018:ffffc90003457c70 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000002 RCX: dffffc0000000000 RDX: dffffc0000000000 RSI: 0000000000000002 RDI: ffff888068ef97d0 RBP: ffff888068ef97d0 R08: 1ffff1100d1df1a9 R09: 0000000000000000 R10: ffff888068ef8e8c R11: fffff5200068af80 R12: 0000000080000000 R13: 1ffffffff1c59fd3 R14: 0000000000000002 R15: ffff888068ef8c40 FS: 00007f652bbf66c0(0000) GS:ffff888124fff000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f652bbd4ff8 CR3: 000000008f37c000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: find_first_zero_bit include/linux/find.h:393 [inline] __mm_get_cid kernel/sched/sched.h:3824 [inline] mm_get_cid kernel/sched/sched.h:3839 [inline] sched_mm_cid_fork+0x592/0xc80 kernel/sched/core.c:10704 bprm_execve+0xda1/0x1460 fs/exec.c:1771 do_execveat_common+0x50d/0x690 fs/exec.c:1846 __do_sys_execveat fs/exec.c:1941 [inline] __se_sys_execveat fs/exec.c:1934 [inline] __x64_sys_execveat+0xc7/0xf0 fs/exec.c:1934 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f652d99c629 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f652bbf6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000142 RAX: ffffffffffffffda RBX: 00007f652dc15fa0 RCX: 00007f652d99c629 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000005 RBP: 00007f652da32b39 R08: 0000000000001000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f652dc16038 R14: 00007f652dc15fa0 R15: 00007fffc12e0528 rcu: rcu_preempt kthread starved for 10496 jiffies! g156653 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:27664 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 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: 1 UID: 0 PID: 23000 Comm: kworker/u8:2 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline] RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline] RIP: 0010:unwind_next_frame+0xd6d/0x23c0 arch/x86/kernel/unwind_orc.c:600 Code: 00 fc ff df 48 8b 4c 24 20 0f b6 04 01 84 c0 0f 85 51 11 00 00 41 83 3e 00 0f 95 c0 49 39 df 0f 96 c1 20 c1 49 39 dc 0f 97 c0 <20> c8 3c 01 75 18 48 8d 43 08 4c 39 f8 0f 97 c1 4c 39 e0 0f 96 c0 RSP: 0018:ffffc90000a07a98 EFLAGS: 00000216 RAX: 0000000000000001 RBX: ffffc90000a08fd8 RCX: 1ffff92000140f01 RDX: ffffffff90c9d5b2 RSI: 0000000000000002 RDI: ffffffff8c2a0aa0 RBP: 1ffff92000140f6e R08: 0000000000000001 R09: ffffffff8e9602e0 R10: ffffc90000a07bb8 R11: ffffffff81b11670 R12: ffffc90000a09000 R13: 1ffff92000140f6f R14: ffffc90000a07b68 R15: ffffc90000a01000 FS: 0000000000000000(0000) GS:ffff8881250ff000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f652d9e9d40 CR3: 000000000e74c000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: 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:5219 [inline] __kmalloc_noprof+0x35c/0x760 mm/slub.c:5231 kmalloc_noprof include/linux/slab.h:966 [inline] kzalloc_noprof include/linux/slab.h:1204 [inline] ieee802_11_parse_elems_full+0x159/0x2ab0 net/mac80211/parse.c:1051 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2480 [inline] ieee80211_inform_bss+0x161/0x1160 net/mac80211/scan.c:79 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline] cfg80211_inform_single_bss_data+0xd08/0x1b70 net/wireless/scan.c:2373 cfg80211_inform_bss_data+0x266/0x3c40 net/wireless/scan.c:3228 cfg80211_inform_bss_frame_data+0x3c7/0x760 net/wireless/scan.c:3319 ieee80211_bss_info_update+0x794/0xa40 net/mac80211/scan.c:230 ieee80211_scan_rx+0x552/0xa40 net/mac80211/scan.c:364 __ieee80211_rx_handle_packet net/mac80211/rx.c:5305 [inline] ieee80211_rx_list+0x29e5/0x3710 net/mac80211/rx.c:5588 ieee80211_rx_napi+0x1b1/0x3e0 net/mac80211/rx.c:5611 ieee80211_rx include/net/mac80211.h:5267 [inline] ieee80211_handle_queued_frames+0xe8/0x1e0 net/mac80211/main.c:452 tasklet_action_common+0x2da/0x4b0 kernel/softirq.c:929 handle_softirqs+0x22a/0x870 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:727 irq_exit_rcu+0x9/0x30 kernel/softirq.c:743 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xcea/0x12c0 kernel/smp.c:877 Code: 89 ee 83 e6 01 31 ff e8 04 e5 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 af e0 0b 00 eb 38 f3 90 42 0f b6 04 2b <84> c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 93 e0 0b 00 eb e4 44 RSP: 0018:ffffc900056bf760 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff11017088515 RCX: ffff88807ae5bc80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900056bf8a0 R08: ffffffff9033cab7 R09: 1ffffffff2067956 R10: dffffc0000000000 R11: fffffbfff2067957 R12: ffff8880b84428a8 R13: dffffc0000000000 R14: ffff8880b853bf80 R15: 0000000000000000 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 on_each_cpu include/linux/smp.h:72 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2746 [inline] smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2956 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:900 process_one_work+0x949/0x1650 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0xb46/0x1140 kernel/workqueue.c:3443 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245