rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (2 ticks this GP) idle=9a5/1/0x4000000000000000 softirq=9340/9340 fqs=0 (detected by 1, t=10502 jiffies, g=11117, q=1147) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5240 Comm: syz.0.210 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:172 [inline] RIP: 0010:write_comp_data kernel/kcov.c:227 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0xc/0x80 kernel/kcov.c:293 Code: 44 02 08 03 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 48 8b 04 24 65 48 8b 0d b4 5c 89 7e <65> 8b 15 b5 5c 89 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 RSP: 0018:ffffc90000007a10 EFLAGS: 00000046 RAX: ffffffff817f39eb RBX: 0000000000000000 RCX: ffff888020ea5940 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000100 R08: ffffffff8d8b0eef R09: 1ffffffff1b161dd R10: dffffc0000000000 R11: fffffbfff1b161de R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff89e00e46 R15: 0000000000000000 FS: 00007ff7d53716c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2b2138 CR3: 000000005b31c000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: trace_irq_enable_rcuidle+0x9b/0x180 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x57/0x4a0 kernel/rcu/tree_plugin.h:625 Code: 00 00 00 fc ff df 48 c7 44 24 20 b3 8a b5 41 48 c7 44 24 28 76 85 c0 8b 48 c7 44 24 30 60 5f 65 81 48 8d 5c 24 20 48 c1 eb 03 <48> b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 RSP: 0018:ffffc90000007b00 EFLAGS: 00000a02 RAX: f0185bbbcc627e00 RBX: 1ffff92000000f64 RCX: ffff888020ea5940 RDX: 0000000000000100 RSI: ffffffff8a7a43a0 RDI: ffff888020ea5940 RBP: ffffc90000007bd8 R08: ffffffff8d8b0eef R09: 1ffffffff1b161dd R10: dffffc0000000000 R11: fffffbfff1b161de R12: 1ffff110041d4baf R13: dffffc0000000000 R14: ffff888020ea5d80 R15: dffffc0000000000 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] ieee80211_iterate_active_interfaces_atomic+0x132/0x140 net/mac80211/util.c:831 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4ea/0xb60 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766 handle_softirqs+0x336/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04 RSP: 0018:ffffc9000328f9e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: f0185bbbcc627e00 RDX: 0000000000000000 RSI: ffffffff8a2b3e80 RDI: ffffffff8a7a43c0 RBP: ffffc9000328faf0 R08: dffffc0000000000 R09: 1ffffffff203de1a R10: dffffc0000000000 R11: fffffbfff203de1b R12: ffffffff8c3decc0 R13: 1ffff92000651f48 R14: 0000000000000246 R15: dffffc0000000000 __fs_reclaim_acquire mm/page_alloc.c:4580 [inline] fs_reclaim_acquire+0x6d/0x100 mm/page_alloc.c:4594 might_alloc include/linux/sched/mm.h:206 [inline] slab_pre_alloc_hook+0x20/0xc0 mm/slab.h:492 slab_alloc_node mm/slub.c:3139 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x3d/0x280 mm/slub.c:3238 kmem_cache_zalloc include/linux/slab.h:728 [inline] lsm_file_alloc security/security.c:578 [inline] security_file_alloc+0x30/0x110 security/security.c:1592 __alloc_file+0xc2/0x240 fs/file_table.c:137 alloc_empty_file+0x90/0x180 fs/file_table.c:181 alloc_file+0x5c/0x510 fs/file_table.c:223 alloc_file_pseudo+0x180/0x200 fs/file_table.c:263 __anon_inode_getfile fs/anon_inodes.c:109 [inline] anon_inode_getfile+0xc1/0x1a0 fs/anon_inodes.c:147 __do_sys_perf_event_open kernel/events/core.c:12623 [inline] __se_sys_perf_event_open+0xc02/0x1bb0 kernel/events/core.c:12397 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff7d7119159 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:00007ff7d5371028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007ff7d73a0fa0 RCX: 00007ff7d7119159 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000d00 RBP: 00007ff7d71b0024 R08: 0000000000000009 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff7d73a1038 R14: 00007ff7d73a0fa0 R15: 00007ffdbb8c3e38 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g11117 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=5112 rcu: rcu_preempt kthread starved for 10502 jiffies! g11117 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28112 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117 rcu_gp_fqs_loop+0x2be/0x11f0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5240 Comm: syz.0.210 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:55 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x57/0x290 mm/kasan/generic.c:189 Code: 0f 82 fa 01 00 00 49 bc 01 00 00 00 00 fc ff df 49 89 fe 49 c1 ee 03 49 ba 00 00 00 00 00 fc ff df 4f 8d 1c 16 4c 8d 44 3e ff <4d> 89 c1 49 c1 e9 03 4b 8d 1c 21 49 89 df 4d 29 df 49 83 ff 10 7f RSP: 0018:ffffc90000007670 EFLAGS: 00000802 RAX: 0000000000000001 RBX: 0000000000000010 RCX: ffffffff81656286 RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffff8880b903b1f0 RBP: 0000000000000000 R08: ffff8880b903b1ff R09: 1ffffffff1b161dd R10: dffffc0000000000 R11: ffffed101720763e R12: dffffc0000000001 R13: dffffc0000000000 R14: 1ffff1101720763e R15: 1ffff11017207641 FS: 00007ff7d53716c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2b2138 CR3: 000000005b31c000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: memset+0x1e/0x40 mm/kasan/shadow.c:44 init_irq_work include/linux/irq_work.h:36 [inline] rcu_read_unlock_special+0x326/0x4a0 kernel/rcu/tree_plugin.h:665 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] BPF_PROG_RUN_ARRAY include/linux/bpf.h:1445 [inline] trace_call_bpf+0x4f9/0x5b0 kernel/trace/bpf_trace.c:127 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10026 perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x57/0x4a0 kernel/rcu/tree_plugin.h:625 Code: 00 00 00 fc ff df 48 c7 44 24 20 b3 8a b5 41 48 c7 44 24 28 76 85 c0 8b 48 c7 44 24 30 60 5f 65 81 48 8d 5c 24 20 48 c1 eb 03 <48> b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 RSP: 0018:ffffc90000007b00 EFLAGS: 00000a02 RAX: f0185bbbcc627e00 RBX: 1ffff92000000f64 RCX: ffff888020ea5940 RDX: 0000000000000100 RSI: ffffffff8a7a43a0 RDI: ffff888020ea5940 RBP: ffffc90000007bd8 R08: ffffffff8d8b0eef R09: 1ffffffff1b161dd R10: dffffc0000000000 R11: fffffbfff1b161de R12: 1ffff110041d4baf R13: dffffc0000000000 R14: ffff888020ea5d80 R15: dffffc0000000000 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] ieee80211_iterate_active_interfaces_atomic+0x132/0x140 net/mac80211/util.c:831 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4ea/0xb60 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766 handle_softirqs+0x336/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04 RSP: 0018:ffffc9000328f9e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: f0185bbbcc627e00 RDX: 0000000000000000 RSI: ffffffff8a2b3e80 RDI: ffffffff8a7a43c0 RBP: ffffc9000328faf0 R08: dffffc0000000000 R09: 1ffffffff203de1a R10: dffffc0000000000 R11: fffffbfff203de1b R12: ffffffff8c3decc0 R13: 1ffff92000651f48 R14: 0000000000000246 R15: dffffc0000000000 __fs_reclaim_acquire mm/page_alloc.c:4580 [inline] fs_reclaim_acquire+0x6d/0x100 mm/page_alloc.c:4594 might_alloc include/linux/sched/mm.h:206 [inline] slab_pre_alloc_hook+0x20/0xc0 mm/slab.h:492 slab_alloc_node mm/slub.c:3139 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x3d/0x280 mm/slub.c:3238 kmem_cache_zalloc include/linux/slab.h:728 [inline] lsm_file_alloc security/security.c:578 [inline] security_file_alloc+0x30/0x110 security/security.c:1592 __alloc_file+0xc2/0x240 fs/file_table.c:137 alloc_empty_file+0x90/0x180 fs/file_table.c:181 alloc_file+0x5c/0x510 fs/file_table.c:223 alloc_file_pseudo+0x180/0x200 fs/file_table.c:263 __anon_inode_getfile fs/anon_inodes.c:109 [inline] anon_inode_getfile+0xc1/0x1a0 fs/anon_inodes.c:147 __do_sys_perf_event_open kernel/events/core.c:12623 [inline] __se_sys_perf_event_open+0xc02/0x1bb0 kernel/events/core.c:12397 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff7d7119159 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:00007ff7d5371028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007ff7d73a0fa0 RCX: 00007ff7d7119159 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000d00 RBP: 00007ff7d71b0024 R08: 0000000000000009 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff7d73a1038 R14: 00007ff7d73a0fa0 R15: 00007ffdbb8c3e38