rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7868/1:b..l rcu: (detected by 1, t=10502 jiffies, g=95785, q=247 ncpus=2) task:syz.4.537 state:R running task stack:24680 pid:7868 tgid:7867 ppid:7192 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5239 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6603 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6925 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:mte_parent lib/maple_tree.c:545 [inline] RIP: 0010:mte_dead_node lib/maple_tree.c:577 [inline] RIP: 0010:mas_start+0x312/0x5a0 lib/maple_tree.c:1369 Code: 00 00 48 8b 04 24 c6 00 00 49 81 e4 00 ff ff ff 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 22 28 73 f6 49 8b 04 24 <48> c7 c1 00 ff ff ff 48 21 c8 4c 39 e0 0f 85 fb 00 00 00 e8 c6 a1 RSP: 0018:ffffc90012d57718 EFLAGS: 00000246 RAX: ffff88807f688041 RBX: ffff88807d57901c RCX: ffff88801bac9e00 RDX: ffffc9000deb5000 RSI: 0000000000000002 RDI: 0000000000000002 RBP: ffffc90012d57820 R08: ffffffff8b882871 R09: 1ffffffff1f5ffad R10: dffffc0000000000 R11: fffffbfff1f5ffae R12: ffff88807d579000 R13: dffffc0000000000 R14: ffffc90012d57858 R15: ffffc90012d57838 mas_state_walk lib/maple_tree.c:3671 [inline] mt_find+0x2dc/0x850 lib/maple_tree.c:6932 find_vma+0xf9/0x170 mm/mmap.c:2019 lock_mm_and_find_vma+0x5f/0x2f0 mm/memory.c:5931 do_user_addr_fault arch/x86/mm/fault.c:1361 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x1bf/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:rep_movs_alternative+0x4a/0x70 arch/x86/lib/copy_user_64.S:71 Code: 75 f1 c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 df 83 f9 08 73 e8 eb c9 a4 c3 cc cc cc cc 48 89 c8 48 c1 e9 03 83 e0 07 f3 48 a5 89 c1 RSP: 0018:ffffc90012d57ad0 EFLAGS: 00050246 RAX: ffffffff84b11e01 RBX: 00000000200e2040 RCX: 0000000000000040 RDX: 0000000000000000 RSI: ffffc90012d57b60 RDI: 00000000200e2000 RBP: ffffc90012d57c10 R08: ffffc90012d57b9f R09: 1ffff920025aaf73 R10: dffffc0000000000 R11: fffff520025aaf74 R12: 0000000000000040 R13: 00000000000ae580 R14: 00000000200e2000 R15: ffffc90012d57b60 copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:131 [inline] _inline_copy_to_user include/linux/uaccess.h:181 [inline] _copy_to_user+0x86/0xb0 lib/usercopy.c:26 copy_to_user include/linux/uaccess.h:209 [inline] rng_dev_read+0x3be/0x6d0 drivers/char/hw_random/core.c:251 do_loop_readv_writev fs/read_write.c:761 [inline] vfs_readv+0x6c2/0xa90 fs/read_write.c:934 do_preadv fs/read_write.c:1049 [inline] __do_sys_preadv fs/read_write.c:1099 [inline] __se_sys_preadv fs/read_write.c:1094 [inline] __x64_sys_preadv+0x1c7/0x2d0 fs/read_write.c:1094 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbb88975bd9 RSP: 002b:00007fbb89688048 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007fbb88b03f60 RCX: 00007fbb88975bd9 RDX: 0000000000000001 RSI: 0000000020000240 RDI: 0000000000000003 RBP: 00007fbb889e4e60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fbb88b03f60 R15: 00007ffd718c0f28 rcu: rcu_preempt kthread starved for 10524 jiffies! g95785 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:25816 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5239 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6603 __schedule_loop kernel/sched/core.c:6680 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6695 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:144 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.10.0-rc7-next-20240712-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline] RIP: 0010:acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:112 Code: 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 40 d7 03 00 48 f7 00 08 00 00 00 75 10 66 90 0f 00 2d 85 07 96 00 f3 0f 1e fa fb f4 c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 RSP: 0018:ffffc900001a7d08 EFLAGS: 00000246 RAX: ffff8880176f0000 RBX: ffff88801b6d3864 RCX: 00000000055e4cc9 RDX: 0000000000000001 RSI: ffff88801b6d3800 RDI: ffff88801b6d3864 RBP: 000000000003a6b8 R08: ffff8880b9537c7b R09: 1ffff110172a6f8f R10: dffffc0000000000 R11: ffffffff8b9437f0 R12: ffff888019bb3800 R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8eadca80 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002006b000 CR3: 0000000068c52000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:702 cpuidle_enter_state+0x112/0x480 drivers/cpuidle/cpuidle.c:267 cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:388 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x375/0x5d0 kernel/sched/idle.c:326 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:424 start_secondary+0x100/0x100 arch/x86/kernel/smpboot.c:313 common_startup_64+0x13e/0x147