rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P21800/1:b..l (detected by 1, t=10502 jiffies, g=222605, q=288 ncpus=2) task:syz.2.4067 state:R running task stack:25232 pid:21800 ppid:16852 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_acquire+0x225/0x4a0 kernel/locking/lockdep.c:5666 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04 RSP: 0018:ffffc900066bf420 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 30441bb2843f1a00 RDX: 0000000000000000 RSI: ffffffff8a8c23a0 RDI: ffffffff8adf0c20 RBP: ffffc900066bf530 R08: dffffc0000000000 R09: 1ffffffff215e648 R10: dffffc0000000000 R11: fffffbfff215e649 R12: 0000000000000001 R13: 1ffff92000cd7e90 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] get_mem_cgroup_from_mm+0x50/0x290 mm/memcontrol.c:1036 __mem_cgroup_charge+0x11/0x80 mm/memcontrol.c:6943 mem_cgroup_charge include/linux/memcontrol.h:672 [inline] shmem_add_to_page_cache+0x90d/0x1c50 mm/shmem.c:708 shmem_get_folio_gfp+0x158e/0x3400 mm/shmem.c:1971 shmem_fault+0x1b6/0x780 mm/shmem.c:2156 __do_fault+0x13b/0x4e0 mm/memory.c:4278 do_read_fault mm/memory.c:4629 [inline] do_fault mm/memory.c:4758 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x2407/0x3ee0 mm/memory.c:5292 faultin_page mm/gup.c:1026 [inline] __get_user_pages+0x40d/0xec0 mm/gup.c:1250 populate_vma_page_range+0x214/0x2b0 mm/gup.c:1607 __mm_populate+0x25c/0x380 mm/gup.c:1721 mm_populate include/linux/mm.h:2891 [inline] vm_mmap_pgoff+0x212/0x2d0 mm/util.c:525 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa08cb9aeb9 RSP: 002b:00007fa08db16028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fa08ce16090 RCX: 00007fa08cb9aeb9 RDX: 0000000000000003 RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007fa08cc08c1f R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa08ce16128 R14: 00007fa08ce16090 R15: 00007ffdb991ddc8 rcu: rcu_preempt kthread starved for 9754 jiffies! g222605 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:27608 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742 Code: 48 89 df e8 a7 10 9d f7 e9 44 ff ff ff e8 7d 07 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d 87 5d 50 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48 RSP: 0018:ffffc90000177de8 EFLAGS: 000002c6 RAX: 59eddb7a74c52c00 RBX: ffffffff8a3651a7 RCX: 59eddb7a74c52c00 RDX: 0000000000000001 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0c20 RBP: ffffc90000177f20 R08: ffff8880b8f3580b R09: 1ffff110171e6b01 R10: dffffc0000000000 R11: ffffed10171e6b02 R12: 1ffff9200002efc8 R13: dffffc0000000000 R14: ffff88813fed9dc0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff1bfed82c9 CR3: 000000002e2be000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 000000000000c280 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: default_idle_call+0x84/0xc0 kernel/sched/idle.c:109 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x20d/0x5a0 kernel/sched/idle.c:303 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401 start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281 secondary_startup_64_no_verify+0xcf/0xdb