rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (119 ticks this GP) idle=763/1/0x4000000000000002 softirq=21544/21544 fqs=0 
	(detected by 1, t=10505 jiffies, g=27049, q=1406)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9646 Comm: syz.1.1504 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__unwind_start+0x5bb/0x740 arch/x86/kernel/unwind_orc.c:-1
Code: 80 3c 30 00 4c 8b 64 24 18 74 08 4c 89 e7 e8 9c fb 88 00 48 8b 44 24 10 49 39 04 24 0f 87 14 fb ff ff 48 89 df e8 95 db ff ff <48> be 00 00 00 00 00 fc ff df 48 8b 04 24 0f b6 04 30 84 c0 75 0e
RSP: 0000:ffffc90000007040 EFLAGS: 00000082
RAX: 0000000000000101 RBX: ffffc90000007100 RCX: 0000000000000101
RDX: ffffc90000007101 RSI: ffffc90000007530 RDI: 00000000ffffffff
RBP: 1ffff92000000e21 R08: ffffc9000000715f R09: ffffc90000007150
R10: dffffc0000000000 R11: fffff52000000e2c R12: ffffc90000007138
R13: ffffc90000007110 R14: 1ffff92000000e22 R15: ffffc90000007108
FS:  00007f39afbc36c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000066b6c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 unwind_start arch/x86/include/asm/unwind.h:60 [inline]
 perf_callchain_kernel+0x2f0/0x720 arch/x86/events/core.c:-1
 get_perf_callchain+0x356/0x460 kernel/events/callchain.c:200
 perf_callchain kernel/events/core.c:7606 [inline]
 perf_prepare_sample+0x352/0x1cd0 kernel/events/core.c:7633
 __perf_event_output kernel/events/core.c:7802 [inline]
 perf_event_output_forward+0x185/0x2e0 kernel/events/core.c:7822
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
 perf_tp_event+0x383/0xbf0 kernel/events/core.c:10047
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
 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+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 12 f2 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0000:ffffc900000079e0 EFLAGS: 00000206
RAX: eda30c2118555200 RBX: 1ffff92000000f40 RCX: eda30c2118555200
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f980
RBP: ffffc90000007ac0 R08: ffffffff901d41bf R09: 1ffffffff203a837
R10: dffffc0000000000 R11: fffffbfff203a838 R12: ffffffff8c322f00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 hsr_announce+0x29a/0x310 net/hsr/hsr_device.c:410
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x53e/0x800 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x339/0x830 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_release+0x5ac/0x8a0 kernel/locking/lockdep.c:5647
Code: 00 00 00 00 02 00 00 43 c6 44 2c 04 f8 75 6f 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 4b c7 04 2c 00 00 00 00 <43> c7 44 2c 08 00 00 00 00 65 48 8b 04 25 28 00 00 00 48 3b 84 24
RSP: 0000:ffffc9000303f3e0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: f379362011fcc2ad RCX: eda30c2118555200
RDX: 0000000000000004 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f980
RBP: ffffc9000303f4f8 R08: ffffffff8d89e36f R09: 1ffffffff1b13c6d
R10: dffffc0000000000 R11: fffffbfff1b13c6e R12: 1ffff92000607e88
R13: dffffc0000000000 R14: ffff888026284660 R15: 0000000000000246
 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/0x290 mm/slub.c:3238
 ptlock_alloc+0x1c/0x60 mm/memory.c:5556
 ptlock_init include/linux/mm.h:2241 [inline]
 pgtable_pte_page_ctor include/linux/mm.h:2268 [inline]
 __pte_alloc_one include/asm-generic/pgalloc.h:66 [inline]
 pte_alloc_one+0xc0/0x310 arch/x86/mm/pgtable.c:33
 __pte_alloc+0x21/0x150 mm/memory.c:439
 copy_pte_range mm/memory.c:1032 [inline]
 copy_pmd_range mm/memory.c:1167 [inline]
 copy_pud_range mm/memory.c:1204 [inline]
 copy_p4d_range mm/memory.c:1228 [inline]
 copy_page_range+0x29c2/0x3230 mm/memory.c:1301
 dup_mmap kernel/fork.c:615 [inline]
 dup_mm kernel/fork.c:1466 [inline]
 copy_mm+0xc86/0x13f0 kernel/fork.c:1518
 copy_process+0x17eb/0x3e20 kernel/fork.c:2290
 kernel_clone+0x23f/0x990 kernel/fork.c:2679
 __do_sys_clone kernel/fork.c:2796 [inline]
 __se_sys_clone kernel/fork.c:2780 [inline]
 __x64_sys_clone+0x19a/0x210 kernel/fork.c:2780
 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: 0033:0x7f39b1969799
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:00007f39afbc2fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f39b1be2fa0 RCX: 00007f39b1969799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000061000600
RBP: 00007f39b19ffbd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f39b1be3038 R14: 00007f39b1be2fa0 R15: 00007fff3458da88
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10504 jiffies! g27049 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=23463
rcu: rcu_preempt kthread starved for 10505 jiffies! g27049 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:26960 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 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/0x11d0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
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: 9646 Comm: syz.1.1504 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:perf_callchain_kernel+0x342/0x720 arch/x86/events/core.c:2784
Code: e7 49 c1 ef 03 48 89 54 24 10 48 c1 ea 03 48 89 54 24 20 48 89 74 24 18 48 c1 ee 03 48 89 74 24 38 48 c1 e8 03 48 89 44 24 30 <48> 8d 7c 24 60 e8 54 13 34 00 49 89 c6 31 ff 48 89 c6 e8 d7 2c 78
RSP: 0000:ffffc900000070a0 EFLAGS: 00000046
RAX: ffffffff8100f919 RBX: ffff88805c2604e0 RCX: ffff888026283b80
RDX: 0000000000000100 RSI: ffffc9000303f648 RDI: 00000000ffffffff
RBP: ffffc900000071d0 R08: ffffc9000000715f R09: ffffc90000007150
R10: dffffc0000000000 R11: fffff52000000e2c R12: ffffc9000000722c
R13: dffffc0000000000 R14: ffffffff8135dc10 R15: 1ffff92000000e45
FS:  00007f39afbc36c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000066b6c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 get_perf_callchain+0x356/0x460 kernel/events/callchain.c:200
 perf_callchain kernel/events/core.c:7606 [inline]
 perf_prepare_sample+0x352/0x1cd0 kernel/events/core.c:7633
 __perf_event_output kernel/events/core.c:7802 [inline]
 perf_event_output_forward+0x185/0x2e0 kernel/events/core.c:7822
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
 perf_tp_event+0x383/0xbf0 kernel/events/core.c:10047
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
 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+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 12 f2 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0000:ffffc900000079e0 EFLAGS: 00000206
RAX: eda30c2118555200 RBX: 1ffff92000000f40 RCX: eda30c2118555200
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f980
RBP: ffffc90000007ac0 R08: ffffffff901d41bf R09: 1ffffffff203a837
R10: dffffc0000000000 R11: fffffbfff203a838 R12: ffffffff8c322f00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 hsr_announce+0x29a/0x310 net/hsr/hsr_device.c:410
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x53e/0x800 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x339/0x830 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_release+0x5ac/0x8a0 kernel/locking/lockdep.c:5647
Code: 00 00 00 00 02 00 00 43 c6 44 2c 04 f8 75 6f 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 4b c7 04 2c 00 00 00 00 <43> c7 44 2c 08 00 00 00 00 65 48 8b 04 25 28 00 00 00 48 3b 84 24
RSP: 0000:ffffc9000303f3e0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: f379362011fcc2ad RCX: eda30c2118555200
RDX: 0000000000000004 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f980
RBP: ffffc9000303f4f8 R08: ffffffff8d89e36f R09: 1ffffffff1b13c6d
R10: dffffc0000000000 R11: fffffbfff1b13c6e R12: 1ffff92000607e88
R13: dffffc0000000000 R14: ffff888026284660 R15: 0000000000000246
 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/0x290 mm/slub.c:3238
 ptlock_alloc+0x1c/0x60 mm/memory.c:5556
 ptlock_init include/linux/mm.h:2241 [inline]
 pgtable_pte_page_ctor include/linux/mm.h:2268 [inline]
 __pte_alloc_one include/asm-generic/pgalloc.h:66 [inline]
 pte_alloc_one+0xc0/0x310 arch/x86/mm/pgtable.c:33
 __pte_alloc+0x21/0x150 mm/memory.c:439
 copy_pte_range mm/memory.c:1032 [inline]
 copy_pmd_range mm/memory.c:1167 [inline]
 copy_pud_range mm/memory.c:1204 [inline]
 copy_p4d_range mm/memory.c:1228 [inline]
 copy_page_range+0x29c2/0x3230 mm/memory.c:1301
 dup_mmap kernel/fork.c:615 [inline]
 dup_mm kernel/fork.c:1466 [inline]
 copy_mm+0xc86/0x13f0 kernel/fork.c:1518
 copy_process+0x17eb/0x3e20 kernel/fork.c:2290
 kernel_clone+0x23f/0x990 kernel/fork.c:2679
 __do_sys_clone kernel/fork.c:2796 [inline]
 __se_sys_clone kernel/fork.c:2780 [inline]
 __x64_sys_clone+0x19a/0x210 kernel/fork.c:2780
 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: 0033:0x7f39b1969799
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:00007f39afbc2fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f39b1be2fa0 RCX: 00007f39b1969799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000061000600
RBP: 00007f39b19ffbd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f39b1be3038 R14: 00007f39b1be2fa0 R15: 00007fff3458da88
 </TASK>