rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=1264/1/0x4000000000000000 softirq=36703/36703 fqs=0 rcu: (detected by 0, t=10502 jiffies, g=47297, q=345 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10232 Comm: syz-executor.1 Not tainted 6.10.0-rc4-syzkaller-00301-g5f583a3162ff #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:__kasan_check_write+0xa/0x20 mm/kasan/shadow.c:37 Code: ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 89 f6 48 8b 0c 24 01 00 00 00 e9 3c e6 ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 RSP: 0018:ffffc90000a18a78 EFLAGS: 00000097 RAX: 0000000000000004 RBX: dffffc0000000000 RCX: ffffffff8173c902 RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffffffff9492ef40 RBP: ffffc90000a18b50 R08: ffffffff92f71587 R09: 1ffffffff25ee2b0 R10: dffffc0000000000 R11: fffffbfff25ee2b1 R12: ffffffff9492ef40 R13: 1ffff9200014315c R14: ffffc90000a18ae0 R15: 1ffffffff2925de9 FS: 00007f16c23ab6c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000080 CR3: 000000005851a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1300 [inline] queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] do_raw_spin_lock+0x142/0x370 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xe1/0x120 kernel/locking/spinlock.c:162 debug_object_activate+0x16d/0x510 lib/debugobjects.c:708 debug_hrtimer_activate kernel/time/hrtimer.c:423 [inline] debug_activate kernel/time/hrtimer.c:478 [inline] enqueue_hrtimer+0x30/0x3c0 kernel/time/hrtimer.c:1085 __run_hrtimer kernel/time/hrtimer.c:1704 [inline] __hrtimer_run_queues+0x6cb/0xd50 kernel/time/hrtimer.c:1751 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1813 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x110/0x3f0 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch+0x1ea/0x870 kernel/sched/core.c:5282 Code: c9 50 e8 99 c9 0b 00 48 83 c4 08 4c 89 f7 e8 cd 38 00 00 e9 de 04 00 00 4c 89 f7 e8 00 51 21 0a e8 fb ed 36 00 fb 48 8b 5d c0 <48> 8d bb f8 15 00 00 48 89 f8 48 c1 e8 03 49 be 00 00 00 00 00 fc RSP: 0018:ffffc9000ed7f648 EFLAGS: 00000286 RAX: 10996b79bd5c2000 RBX: ffff88807a471e00 RCX: ffffffff8172d71a RDX: dffffc0000000000 RSI: ffffffff8bcabb80 RDI: ffffffff8c1f1800 RBP: ffffc9000ed7f690 R08: ffffffff92f715b7 R09: 1ffffffff25ee2b6 R10: dffffc0000000000 R11: fffffbfff25ee2b7 R12: 1ffff110172a7e97 R13: dffffc0000000000 R14: ffff8880b943e740 R15: ffff8880b953f4b8 context_switch kernel/sched/core.c:5411 [inline] __schedule+0x179e/0x49d0 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6894 rwsem_down_read_slowpath kernel/locking/rwsem.c:1086 [inline] __down_read_common kernel/locking/rwsem.c:1250 [inline] __down_read_killable kernel/locking/rwsem.c:1273 [inline] down_read_killable+0x880/0xd30 kernel/locking/rwsem.c:1551 mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:153 get_mmap_lock_carefully mm/memory.c:5724 [inline] lock_mm_and_find_vma+0x29c/0x2f0 mm/memory.c:5775 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+0x33/0x70 arch/x86/lib/copy_user_64.S:58 Code: 40 83 f9 08 73 21 85 c9 74 0f 8a 06 88 07 48 ff c7 48 ff c6 48 ff c9 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 RSP: 0018:ffffc9000ed7fbb0 EFLAGS: 00050246 RAX: 0000000000000000 RBX: 0000000020022008 RCX: 0000000000000008 RDX: 0000000000000000 RSI: ffffc9000ed7fc20 RDI: 0000000020022000 RBP: ffffc9000ed7fc90 R08: ffffc9000ed7fc27 R09: 1ffff92001daff84 R10: dffffc0000000000 R11: fffff52001daff85 R12: 0000000000000008 R13: 0000000000018fe8 R14: 0000000020022000 R15: ffffc9000ed7fc20 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] _copy_to_user+0x86/0xb0 lib/usercopy.c:46 copy_to_user include/linux/uaccess.h:191 [inline] msr_read+0x187/0x260 arch/x86/kernel/msr.c:69 vfs_read+0x204/0xbd0 fs/read_write.c:474 ksys_read+0x1a0/0x2c0 fs/read_write.c:619 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: 0033:0x7f16c167d0a9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f16c23ab0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f16c17b3f80 RCX: 00007f16c167d0a9 RDX: 0000000000018ff0 RSI: 0000000020019680 RDI: 0000000000000003 RBP: 00007f16c16ec074 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f16c17b3f80 R15: 00007ffda01aa458 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g47297 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=22018 rcu: rcu_preempt kthread starved for 10502 jiffies! g47297 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:25232 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x1796/0x49d0 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2000 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2202 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244