rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5792/1:b..l rcu: (detected by 1, t=10503 jiffies, g=8841, q=23 ncpus=2) task:syz-executor401 state:R running task stack:28680 pid:5792 ppid:5770 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:lock_is_held_type+0x13e/0x190 kernel/locking/lockdep.c:5830 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc90004787940 EFLAGS: 00000206 RAX: 9b955fa08a09f200 RBX: ffff888024ec0000 RCX: 9b955fa08a09f200 RDX: 0000000000000000 RSI: ffffffff8acadb60 RDI: ffffffff8b1c89a0 RBP: 0000000000000000 R08: dffffc0000000000 R09: 1ffffffff22386a0 R10: dffffc0000000000 R11: fffffbfff22386a1 R12: 0000000000000002 R13: 0000000000000246 R14: ffffffff8d15bb78 R15: ffff888024ec0b30 lock_is_held include/linux/lockdep.h:288 [inline] task_css include/linux/cgroup.h:436 [inline] mem_cgroup_from_task+0x77/0x110 mm/memcontrol.c:1038 get_mem_cgroup_from_mm+0xd6/0x290 mm/memcontrol.c:1091 __mem_cgroup_charge+0x15/0x80 mm/memcontrol.c:7110 mem_cgroup_charge include/linux/memcontrol.h:686 [inline] wp_page_copy mm/memory.c:3118 [inline] do_wp_page+0x14b0/0x35f0 mm/memory.c:3469 handle_pte_fault mm/memory.c:5063 [inline] __handle_mm_fault mm/memory.c:5188 [inline] handle_mm_fault+0x135d/0x4c00 mm/memory.c:5353 do_user_addr_fault+0x730/0x12c0 arch/x86/mm/fault.c:1371 handle_page_fault arch/x86/mm/fault.c:1463 [inline] exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0010:__put_user_4+0x11/0x20 arch/x86/lib/putuser.S:89 Code: 01 ca c3 90 90 90 90 90 90 f3 0f 1e fa 0f 01 cb 66 89 01 31 c9 0f 01 ca c3 f3 0f 1e fa 48 89 cb 48 c1 fb 3f 48 09 d9 0f 01 cb <89> 01 31 c9 0f 01 ca c3 90 90 90 90 90 90 90 f3 0f 1e fa 0f 01 cb RSP: 0018:ffffc90004787ef8 EFLAGS: 00050206 RAX: 0000000000000003 RBX: 0000000000000000 RCX: 0000555578759690 RDX: 0000000000000000 RSI: ffffffff8acadb60 RDI: ffffffff8b1c89a0 RBP: 0000000000000000 R08: ffffffff8e8b02af R09: 1ffffffff1d16055 R10: dffffc0000000000 R11: fffffbfff1d16056 R12: 1ffff110049d80d2 R13: 0000000000000000 R14: ffff888024ec0000 R15: dffffc0000000000 schedule_tail+0x93/0xb0 kernel/sched/core.c:5316 ret_from_fork+0x24/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: rcu_preempt kthread starved for 10533 jiffies! g8841 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:27656 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 5791 Comm: syz-executor401 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 00 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 5a fd d8 f6 48 89 df e8 12 d2 d9 f6 e8 dd e2 fd f6 fb bf 01 00 00 00 f2 d8 cc f6 65 8b 05 63 06 74 75 85 c0 74 02 5b c3 e8 e0 ed 70 RSP: 0018:ffffc90004777c78 EFLAGS: 00000286 RAX: bd3287ca134bc100 RBX: ffff88802abedc80 RCX: bd3287ca134bc100 RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: 0000000000000001 RBP: ffff88802abee118 R08: ffffffff8e8b02af R09: 1ffffffff1d16055 R10: dffffc0000000000 R11: fffffbfff1d16056 R12: 1ffff1100557dc23 R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000 FS: 00005555787593c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000bbdffc CR3: 000000002eab7000 CR4: 00000000003506e0 Call Trace: spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x11f5/0x13f0 kernel/signal.c:2905 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fbc211c6bee Code: 08 0f 85 45 e1 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 90 41 57 41 56 4d 89 c6 41 55 4d 89 cd 41 54 55 53 48 83 ec 08 RSP: 002b:00007ffd512d1f98 EFLAGS: 00000246 RAX: fffffffffffffff7 RBX: 00005555787593c0 RCX: 00007fbc211c6bee RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000013 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbc212300b2 R13: 00007fbc2122e12a R14: 00007ffd512d2030 R15: 0000000000000000