rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12897/1:b..l rcu: (detected by 0, t=10502 jiffies, g=109961, q=759 ncpus=2) task:syz.4.874 state:R running task stack:21528 pid:12897 tgid:12897 ppid:11114 task_flags:0x40064c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7370 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] zap_pte_range mm/memory.c:1964 [inline] zap_pmd_range mm/memory.c:2020 [inline] zap_pud_range mm/memory.c:2048 [inline] zap_p4d_range mm/memory.c:2069 [inline] __zap_vma_range+0x3d26/0x4b50 mm/memory.c:2109 unmap_vmas+0x379/0x530 mm/memory.c:2178 exit_mmap+0x280/0x9e0 mm/mmap.c:1300 __mmput+0x118/0x430 kernel/fork.c:1178 exit_mm+0x1f6/0x2d0 kernel/exit.c:582 do_exit+0x6a2/0x22c0 kernel/exit.c:964 do_group_exit+0x21b/0x2d0 kernel/exit.c:1119 get_signal+0x1284/0x1330 kernel/signal.c:3037 arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop kernel/entry/common.c:98 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline] irqentry_exit+0x289/0x760 kernel/entry/common.c:162 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7fa01f19ce61 RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fa01f416090 RCX: 00007fa01f19ce59 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007fa01f232d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fa01f416128 R14: 00007fa01f416090 R15: 00007ffe215e9ff8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10498 jiffies! g109961 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=58156 rcu: rcu_preempt kthread starved for 10499 jiffies! g109961 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 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+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 13033 Comm: modprobe Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:rb_erase_linked+0x17b/0x190 lib/rbtree.c:462 Code: ef 31 f6 e8 67 97 8c f6 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 81 94 8c f6 48 83 3b 00 0f 95 c0 48 83 c4 10 5b <41> 5c 41 5d 41 5e 41 5f 5d e9 c2 d2 6b f5 cc 66 0f 1f 44 00 00 90 RSP: 0018:ffffc90000a08d60 EFLAGS: 00000082 RAX: 1ffff110170e5001 RBX: 1ffff1100f2ef467 RCX: 0000000000000000 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffff88807977a328 RBP: ffff88807977a318 R08: ffff88807977a327 R09: ffff88807977a318 R10: dffffc0000000000 R11: ffffed100f2ef465 R12: ffffffff9a493258 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88807977a300 FS: 0000000000000000(0000) GS:ffff888125389000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a0ae778008 CR3: 00000000202f2000 CR4: 0000000000350ef0 Call Trace: timerqueue_linked_del include/linux/timerqueue.h:66 [inline] __remove_hrtimer+0xf7/0x3e0 kernel/time/hrtimer.c:1155 __run_hrtimer kernel/time/hrtimer.c:1910 [inline] __hrtimer_run_queues+0x299/0xa20 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:vm_area_alloc+0x27/0x140 mm/vma_init.c:33 Code: 90 90 90 0f 1f 40 d6 41 57 41 56 41 54 53 49 89 ff e8 dd dc af ff 48 8b 3d b6 81 34 18 be c0 0c 00 00 e8 6c 6d 0f 00 48 89 c3 <48> 85 c0 0f 84 d9 00 00 00 49 89 c6 49 bc 00 00 00 00 00 fc ff df RSP: 0018:ffffc90004a9f038 EFLAGS: 00000296 RAX: ffff8880784fb8c0 RBX: ffff8880784fb8c0 RCX: 0000000080000001 RDX: ffff88801bef1b40 RSI: ffffffff8c28b640 RDI: ffffffff8c28b600 RBP: ffffc90004a9f690 R08: 00000000ffffffff R09: 00000000b974602b R10: 000000000000000f R11: ffffffff81b0f020 R12: dffffc0000000000 R13: 1ffff92000953e60 R14: ffffc90004a9f550 R15: ffff888035471880 __mmap_new_vma mm/vma.c:2547 [inline] __mmap_region mm/vma.c:2771 [inline] mmap_region+0x11c6/0x22a0 mm/vma.c:2857 do_mmap+0xc39/0x10c0 mm/mmap.c:560 vm_mmap_pgoff+0x2c9/0x4f0 mm/util.c:581 elf_map fs/binfmt_elf.c:400 [inline] elf_load+0x247/0x6b0 fs/binfmt_elf.c:423 load_elf_interp+0x4ce/0xb60 fs/binfmt_elf.c:689 load_elf_binary+0x1b2f/0x2980 fs/binfmt_elf.c:1254 search_binary_handler fs/exec.c:1664 [inline] exec_binprm fs/exec.c:1696 [inline] bprm_execve+0x94a/0x1510 fs/exec.c:1748 kernel_execve+0x844/0x930 fs/exec.c:1892 call_usermodehelper_exec_async+0x20f/0x360 kernel/umh.c:109 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245