rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P23908/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=122157, q=673 ncpus=2)
task:syz.0.4381      state:R  running task     stack:24200 pid:23908 tgid:23901 ppid:19031  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1821/0x5740 kernel/sched/core.c:7189
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
 irqentry_exit+0x14f/0x760 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 f1 8d 08 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 db a8 98 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 40 81 0b 0a cc 48 8d 3d 88 c2 92
RSP: 0018:ffffc9000d70e678 EFLAGS: 00000286
RAX: 218f78e03433e200 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000cdac3f13 RSI: ffffffff8e2249cb RDI: ffffffff8c28afe0
RBP: ffffffff8176f256 R08: ffffffff8176f256 R09: ffffffff8e95cda0
R10: ffffc9000d70e7d8 R11: ffffffff81b0efc0 R12: 0000000000000002
R13: ffffffff8e95cda0 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 rcu_read_lock include/linux/rcupdate.h:838 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
 unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 save_stack+0x122/0x230 mm/page_owner.c:165
 __set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858
 prep_new_page mm/page_alloc.c:1866 [inline]
 get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226
 alloc_pages_mpol+0x235/0x490 mm/mempolicy.c:2490
 folio_alloc_mpol_noprof+0x39/0x160 mm/mempolicy.c:2509
 shmem_alloc_folio mm/shmem.c:1933 [inline]
 shmem_alloc_and_add_folio+0x442/0xf80 mm/shmem.c:1975
 shmem_get_folio_gfp+0x5a9/0x1670 mm/shmem.c:2564
 shmem_fault+0x179/0x390 mm/shmem.c:2765
 __do_fault+0x138/0x2a0 mm/memory.c:5458
 do_read_fault mm/memory.c:5893 [inline]
 do_fault mm/memory.c:6027 [inline]
 do_pte_missing+0x2093/0x33f0 mm/memory.c:4550
 handle_pte_fault mm/memory.c:6411 [inline]
 __handle_mm_fault mm/memory.c:6549 [inline]
 handle_mm_fault+0x1bd9/0x3170 mm/memory.c:6718
 do_user_addr_fault+0x75b/0x1340 arch/x86/mm/fault.c:1385
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0010:rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:74
Code: cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08 73 e8 eb c5 <f3> a4 c3 cc cc cc cc 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48
RSP: 0018:ffffc9000d70f5f8 EFLAGS: 00050206
RAX: 00007ffffffff001 RBX: dffffc0000000000 RCX: 00000000000006d4
RDX: 0000000000000001 RSI: 00002000004b7000 RDI: ffff88806690192c
RBP: ffffc9000d70f760 R08: ffff888066901fff R09: 1ffff1100cd203ff
R10: dffffc0000000000 R11: ffffed100cd20400 R12: ffffc9000d70fdf0
R13: 00000000004b64d4 R14: 0000000000001000 R15: 0000000000001000
 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
 raw_copy_from_user arch/x86/include/asm/uaccess_64.h:141 [inline]
 copy_from_user_iter lib/iov_iter.c:67 [inline]
 iterate_iovec include/linux/iov_iter.h:52 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:304 [inline]
 iterate_and_advance include/linux/iov_iter.h:330 [inline]
 __copy_from_iter lib/iov_iter.c:261 [inline]
 _copy_from_iter+0x408/0x1670 lib/iov_iter.c:272
 copy_page_from_iter+0x220/0x2d0 lib/iov_iter.c:434
 skb_copy_datagram_from_iter+0x306/0x710 net/core/datagram.c:581
 unix_stream_sendmsg+0x5f3/0xe80 net/unix/af_unix.c:2471
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
 __sys_sendmsg net/socket.c:2784 [inline]
 __do_sys_sendmsg net/socket.c:2789 [inline]
 __se_sys_sendmsg net/socket.c:2787 [inline]
 __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd1f219ce59
RSP: 002b:00007fd1f311e028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fd1f2416090 RCX: 00007fd1f219ce59
RDX: 0000000000000000 RSI: 0000200000001580 RDI: 0000000000000008
RBP: 00007fd1f2232d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd1f2416128 R14: 00007fd1f2416090 R15: 00007ffce5c2b638
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g122157 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=46079
rcu: rcu_preempt kthread starved for 10502 jiffies! g122157 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:
 <TASK>
 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
 </TASK>
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: 23929 Comm: syz.1.4388 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4882 [inline]
RIP: 0010:__lock_acquire+0x56f/0x2cf0 kernel/locking/lockdep.c:5187
Code: 85 c0 74 1c 83 3d 64 90 8f 0e 00 75 13 48 8d 3d f7 bb 92 0e 48 c7 c6 f0 ed 0c 8e 67 48 0f b9 3a 90 31 c9 0f b6 81 c4 00 00 00 <84> c0 0f 84 77 ff ff ff 41 0f b6 f4 0f b6 d0 40 38 c6 0f 42 d6 80
RSP: 0018:ffffc90000a08b80 EFLAGS: 00000006
RAX: 0000000000000002 RBX: ffff88802ed5aae8 RCX: ffffffff93e38e10
RDX: 0000000000000002 RSI: 0000000000004000 RDI: 0000000000000000
RBP: ffff88802ed5aaf0 R08: ffffffff84bca7fc R09: ffffffff9a6aed40
R10: ffff888034c65308 R11: ffffed100698ca63 R12: 0000000000000002
R13: ffff88802ed5aaf0 R14: ffff88802ed59ec0 R15: 0000000000000003
FS:  0000000000000000(0000) GS:ffff88812537a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3281e2 CR3: 000000000e74a000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
 _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166
 debug_object_deactivate+0x6c/0x3a0 lib/debugobjects.c:890
 debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1898 [inline]
 __hrtimer_run_queues+0x23a/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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__sanitizer_cov_trace_pc+0x5c/0x70 kernel/kcov.c:235
Code: b0 16 00 00 83 fa 02 75 21 48 8b 91 b8 16 00 00 48 8b 32 48 8d 7e 01 8b 89 b4 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 <c3> cc cc cc cc cc 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90
RSP: 0018:ffffc9000d6af378 EFLAGS: 00000293
RAX: ffffffff8178c0d4 RBX: 800000009e17e007 RCX: ffff88802ed59ec0
RDX: 0000000000000000 RSI: 800000009e17e007 RDI: ffff888075200c80
RBP: ffffc9000d6af690 R08: ffffea0002785f87 R09: 1ffffd40004f0bf0
R10: dffffc0000000000 R11: fffff940004f0bf1 R12: dffffc0000000000
R13: 800000009e17e007 R14: ffff888075200c80 R15: ffffea0002785f80
 arch_check_zapped_pte+0x14/0xb0 arch/x86/mm/pgtable.c:823
 zap_present_folio_ptes mm/memory.c:1649 [inline]
 zap_present_ptes mm/memory.c:1714 [inline]
 do_zap_pte_range mm/memory.c:1816 [inline]
 zap_pte_range mm/memory.c:1918 [inline]
 zap_pmd_range mm/memory.c:2004 [inline]
 zap_pud_range mm/memory.c:2032 [inline]
 zap_p4d_range mm/memory.c:2053 [inline]
 __zap_vma_range+0x1fd8/0x4b40 mm/memory.c:2093
 unmap_vmas+0x379/0x530 mm/memory.c:2162
 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+0x8c/0x4d0 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdb4c59ce59
Code: Unable to access opcode bytes at 0x7fdb4c59ce2f.
RSP: 002b:00007fdb4d5060e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fdb4c815fa8 RCX: 00007fdb4c59ce59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fdb4c815fa8
RBP: 00007fdb4c815fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdb4c816038 R14: 00007ffdcc84f080 R15: 00007ffdcc84f168
 </TASK>