rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9145/1:b..l P10345/1:b..l rcu: (detected by 1, t=10502 jiffies, g=48901, q=281 ncpus=2) task:syz.3.1328 state:R running task stack:26288 pid:10345 tgid:10344 ppid:8856 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5239 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6603 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6782 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6806 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1688 [inline] zap_pmd_range mm/memory.c:1736 [inline] zap_pud_range mm/memory.c:1765 [inline] zap_p4d_range mm/memory.c:1786 [inline] unmap_page_range+0x3818/0x42c0 mm/memory.c:1807 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1897 exit_mmap+0x264/0xc80 mm/mmap.c:3412 __mmput+0x115/0x390 kernel/fork.c:1347 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x27f0 kernel/exit.c:869 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 get_signal+0x16a1/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x830 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9e71375a99 RSP: 002b:00007f9e721f30f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f9e71503f68 RCX: 00007f9e71375a99 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f9e71503f68 RBP: 00007f9e71503f60 R08: 00007f9e721f36c0 R09: 00007f9e721f36c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9e71503f6c R13: 000000000000000b R14: 00007ffd5cb8ee60 R15: 00007ffd5cb8ef48 task:syz.4.1003 state:R running task stack:24872 pid:9145 tgid:9144 ppid:8409 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:lock_is_held_type+0x13b/0x190 Code: 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 42 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc9000321f2f8 EFLAGS: 00000206 RAX: 314361a533134600 RBX: 0000000000000001 RCX: 0000000080000000 RDX: ffff88806dd98000 RSI: ffffffff8bcae740 RDI: ffffffff8c20a0e0 RBP: 0000000000000002 R08: ffffffff8b8f9337 R09: 1ffffffff2601f00 R10: dffffc0000000000 R11: fffffbfff2601f01 R12: 0000000000000246 R13: ffff88806dd98000 R14: 00000000ffffffff R15: ffffffff8e337aa0 xa_entry include/linux/xarray.h:1220 [inline] xas_descend lib/xarray.c:207 [inline] xas_load+0x478/0x5c0 lib/xarray.c:245 filemap_get_entry+0x1f0/0x3b0 mm/filemap.c:1840 __filemap_get_folio+0x79/0xc10 mm/filemap.c:1885 __find_get_block_slow fs/buffer.c:203 [inline] __find_get_block+0x28a/0x1150 fs/buffer.c:1408 __getblk_slow fs/buffer.c:1135 [inline] bdev_getblk+0x18d/0x550 fs/buffer.c:1441 __bread_gfp+0x86/0x400 fs/buffer.c:1495 sb_bread include/linux/buffer_head.h:347 [inline] get_branch+0x2c3/0x6e0 fs/sysv/itree.c:102 get_block+0x180/0x16d0 fs/sysv/itree.c:222 block_read_full_folio+0x418/0xcd0 fs/buffer.c:2406 filemap_read_folio+0x1a0/0x790 mm/filemap.c:2355 do_read_cache_folio+0x134/0x820 mm/filemap.c:3789 do_read_cache_page+0x30/0x200 mm/filemap.c:3855 read_mapping_page include/linux/pagemap.h:907 [inline] dir_get_page fs/sysv/dir.c:64 [inline] sysv_readdir+0x190/0x3e0 fs/sysv/dir.c:92 iterate_dir+0x57a/0x810 fs/readdir.c:108 __do_sys_getdents64 fs/readdir.c:407 [inline] __se_sys_getdents64+0x20d/0x4f0 fs/readdir.c:392 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: 0033:0x7f0cc9775a99 RSP: 002b:00007f0cca4db048 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00007f0cc9903f60 RCX: 00007f0cc9775a99 RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007f0cc97e4e5d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f0cc9903f60 R15: 00007fff066742c8 rcu: rcu_preempt kthread starved for 10248 jiffies! g48901 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:25200 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-next-20240717-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 b5 89 95 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: ffff88801cec8864 RCX: 0000000001331209 RDX: 0000000000000001 RSI: ffff88801cec8800 RDI: ffff88801cec8864 RBP: 000000000003a6b8 R08: ffff8880b9537c7b R09: 1ffff110172a6f8f R10: dffffc0000000000 R11: ffffffff8b94b7e0 R12: ffff88801cf29000 R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8eadce40 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d11eff8 CR3: 000000002bad8000 CR4: 00000000003506f0 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