rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=b894/1/0x4000000000000000 softirq=20849/20849 fqs=30
rcu: 	(detected by 1, t=10502 jiffies, g=21817, q=495 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6867 Comm: syz.1.308 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:num_possible_cpus include/linux/cpumask.h:1222 [inline]
RIP: 0010:mm_get_cid kernel/sched/sched.h:3839 [inline]
RIP: 0010:sched_mm_cid_fork+0x56c/0xc80 kernel/sched/core.c:10704
Code: 00 00 0f b6 c0 41 29 c6 4c 89 e3 e9 64 ff ff ff 49 c7 c5 98 fe 2c 8e 49 c1 ed 03 eb 0b 44 89 e0 f7 d8 0f 81 2a fd ff ff f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 50 44 8b
RSP: 0018:ffffc900030d7c78 EFLAGS: 00000887
RAX: 0000000080000000 RBX: 0000000000000002 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: 0000000000000002 RDI: ffff888021f62410
RBP: ffff888021f62410 R08: 1ffff110043ec331 R09: 0000000000000000
R10: ffff888021f61acc R11: fffff5200061af80 R12: 0000000080000000
R13: 1ffffffff1c59fd3 R14: 0000000000000002 R15: ffff888021f61880
FS:  00007fe7ae7136c0(0000) GS:ffff888124fff000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f899d217dac CR3: 0000000036ab2000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 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: 0033:0x7fe7ad79c629
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:00007fe7ae713028 EFLAGS: 00000246 ORIG_RAX: 0000000000000142
RAX: ffffffffffffffda RBX: 00007fe7ada16090 RCX: 00007fe7ad79c629
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007fe7ad832b39 R08: 0000000000001000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe7ada16128 R14: 00007fe7ada16090 R15: 00007ffe8f272108
 </TASK>
rcu: rcu_preempt kthread starved for 10442 jiffies! g21817 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:
 <TASK>
 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
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 6874 Comm: syz.2.312 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:194
Code: f7 e8 ed 02 e5 f5 f7 c3 00 02 00 00 74 05 e8 d0 57 10 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 34 c9 d6 f5 65 8b 05 9d 8f 84 07 85 c0 74 18 5b 41 5e e9 81 48
RSP: 0018:ffffc90000a08a88 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000246 RCX: 0000000000000104
RDX: 0000000000000002 RSI: ffffffff8e0150a1 RDI: 0000000000000001
RBP: ffffc90000a08d70 R08: ffffffff9033cab7 R09: 1ffffffff2067956
R10: dffffc0000000000 R11: fffffbfff2067957 R12: dffffc0000000000
R13: 000000000000d000 R14: ffff888029fdc000 R15: ffff88802a0dd470
FS:  00007f899df296c0(0000) GS:ffff8881250ff000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001148 CR3: 000000007b818000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 spin_unlock_irqrestore include/linux/spinlock.h:407 [inline]
 dummy_timer+0x44a2/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:-1
 __run_hrtimer kernel/time/hrtimer.c:1785 [inline]
 __hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849
 hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1866
 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
 </IRQ>
 <TASK>
 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:ffffc900025ef2a0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff11017088515 RCX: 0000000000080000
RDX: ffffc9000d8db000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc900025ef3c8 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
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:57 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
 flush_tlb_mm_range+0x5c3/0x10c0 arch/x86/mm/tlb.c:1472
 pmdp_invalidate+0x262/0x2d0 mm/pgtable-generic.c:204
 __split_huge_pmd_locked mm/huge_memory.c:3124 [inline]
 split_huge_pmd_locked+0x12d0/0x3720 mm/huge_memory.c:3273
 __split_huge_pmd+0x202/0x2e0 mm/huge_memory.c:3287
 split_huge_pmd_address mm/huge_memory.c:3300 [inline]
 split_huge_pmd_if_needed mm/huge_memory.c:3312 [inline]
 vma_adjust_trans_huge+0x269/0x370 mm/huge_memory.c:3324
 __split_vma+0x7ce/0xa40 mm/vma.c:554
 split_vma mm/vma.c:596 [inline]
 vma_modify+0x91b/0x2060 mm/vma.c:1672
 vma_modify_flags+0x24b/0x330 mm/vma.c:1700
 mprotect_fixup+0x47a/0xa80 mm/mprotect.c:756
 do_mprotect_pkey+0x8ab/0xcd0 mm/mprotect.c:930
 __do_sys_mprotect mm/mprotect.c:951 [inline]
 __se_sys_mprotect mm/mprotect.c:948 [inline]
 __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:948
 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: 0033:0x7f899cf9c629
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:00007f899df29028 EFLAGS: 00000246 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 00007f899d215fa0 RCX: 00007f899cf9c629
RDX: 0000000000000002 RSI: 0000000000004000 RDI: 0000200000293000
RBP: 00007f899d032b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f899d216038 R14: 00007f899d215fa0 R15: 00007ffedece3a28
 </TASK>