rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13050/1:b..l P13255/1:b..l P13033/1:b..l rcu: (detected by 1, t=10502 jiffies, g=65985, q=897 ncpus=2) task:syz.0.1304 state:R running task stack:23320 pid:13033 tgid:13033 ppid:5870 task_flags:0x40064c flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288 irqentry_exit+0x36/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872 Code: 3d 3e 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 e2 08 14 0f 0f 82 74 02 00 00 8b 35 8a 3a 14 0f 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 39 3d 3e 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc9000b7f6f40 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e5c0fe0 RCX: 00000000ef9d33e4 RDX: 0000000000000000 RSI: ffffffff8de2654d RDI: ffffffff8c162900 RBP: 0000000000000002 R08: 0ac0d5affe09d4ff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] free_unref_folios+0xa61/0x16b0 mm/page_alloc.c:2952 folios_put_refs+0x56f/0x740 mm/swap.c:997 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x58f/0x1150 mm/shmem.c:1157 shmem_truncate_range mm/shmem.c:1269 [inline] shmem_evict_inode+0x3a1/0xbe0 mm/shmem.c:1397 evict+0x3e3/0x920 fs/inode.c:810 iput_final fs/inode.c:1897 [inline] iput fs/inode.c:1923 [inline] iput+0x521/0x880 fs/inode.c:1909 dentry_unlink_inode+0x29c/0x480 fs/dcache.c:466 __dentry_kill+0x1d0/0x600 fs/dcache.c:669 dput.part.0+0x4b1/0x9b0 fs/dcache.c:911 dput+0x1f/0x30 fs/dcache.c:901 __fput+0x51c/0xb70 fs/file_table.c:476 task_work_run+0x150/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x86f/0x2bf0 kernel/exit.c:961 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:40 [inline] exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] irqentry_exit_to_user_mode+0x12a/0x270 kernel/entry/common.c:73 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x0 RSP: 002b:000000000000000a EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007febcb1b6180 RCX: 00007febcaf8ebe9 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000020003b46 RBP: 00007febcb011e19 R08: 0000000000000002 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007febcb1b6218 R14: 00007febcb1b6180 R15: 00007fff3c8f4628 task:syz.2.1355 state:R running task stack:26888 pid:13255 tgid:13252 ppid:5874 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288 irqentry_exit+0x36/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872 Code: 3d 3e 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 e2 08 14 0f 0f 82 74 02 00 00 8b 35 8a 3a 14 0f 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 39 3d 3e 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc9001861edc0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e5c0fe0 RCX: 0000000030199c30 RDX: 0000000000000000 RSI: ffffffff8de2654d RDI: ffffffff8c162900 RBP: 0000000000000002 R08: b9cd42b6370c8f6b R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __set_page_owner+0x91/0x550 mm/page_owner.c:329 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline] alloc_pages_noprof+0x131/0x390 mm/mempolicy.c:2507 vm_area_alloc_pages mm/vmalloc.c:3642 [inline] __vmalloc_area_node mm/vmalloc.c:3720 [inline] __vmalloc_node_range_noprof+0x72f/0x14b0 mm/vmalloc.c:3893 __vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:3956 __snd_dma_alloc_pages+0x53/0x90 sound/core/memalloc.c:45 snd_dma_alloc_dir_pages+0x151/0x240 sound/core/memalloc.c:79 do_alloc_pages+0x136/0x2d0 sound/core/pcm_memory.c:69 snd_pcm_lib_malloc_pages+0x3df/0x980 sound/core/pcm_memory.c:455 snd_pcm_hw_params+0x1656/0x1ba0 sound/core/pcm_native.c:791 snd_pcm_kernel_ioctl+0x147/0x2e0 sound/core/pcm_native.c:3494 snd_pcm_oss_change_params_locked+0x1432/0x3a30 sound/core/oss/pcm_oss.c:965 snd_pcm_oss_make_ready_locked+0xb7/0x130 sound/core/oss/pcm_oss.c:1186 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1514 [inline] snd_pcm_oss_read+0x39b/0x760 sound/core/oss/pcm_oss.c:2772 do_loop_readv_writev fs/read_write.c:847 [inline] do_loop_readv_writev fs/read_write.c:835 [inline] vfs_readv+0x5be/0x8b0 fs/read_write.c:1020 do_readv+0x132/0x340 fs/read_write.c:1080 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1dfd98ebe9 RSP: 002b:00007f1dfe851038 EFLAGS: 00000246 ORIG_RAX: 0000000000000013 RAX: ffffffffffffffda RBX: 00007f1dfdbb6180 RCX: 00007f1dfd98ebe9 RDX: 0000000000000001 RSI: 0000200000000a80 RDI: 0000000000000003 RBP: 00007f1dfda11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1dfdbb6218 R14: 00007f1dfdbb6180 R15: 00007ffeaede6158 task:syz.0.1306 state:R running task stack:23320 pid:13050 tgid:13050 ppid:5870 task_flags:0x400640 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288 irqentry_exit+0x36/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872 Code: 3d 3e 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 e2 08 14 0f 0f 82 74 02 00 00 8b 35 8a 3a 14 0f 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 39 3d 3e 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc9000b8060d0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e5c0fe0 RCX: 00000000bfab6211 RDX: 0000000000000000 RSI: ffffffff8de2654d RDI: ffffffff8c162900 RBP: 0000000000000002 R08: 61bb423fac2630d0 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __set_page_owner+0x91/0x550 mm/page_owner.c:329 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 folio_alloc_mpol_noprof+0x36/0x2f0 mm/mempolicy.c:2435 shmem_alloc_folio+0x135/0x160 mm/shmem.c:1908 shmem_alloc_and_add_folio+0x499/0xc20 mm/shmem.c:1947 shmem_get_folio_gfp+0x67f/0x1600 mm/shmem.c:2597 shmem_fault+0x1fe/0xa30 mm/shmem.c:2798 __do_fault+0x10a/0x490 mm/memory.c:5152 do_read_fault mm/memory.c:5573 [inline] do_fault mm/memory.c:5707 [inline] do_pte_missing+0xf50/0x3ba0 mm/memory.c:4234 handle_pte_fault mm/memory.c:6052 [inline] __handle_mm_fault+0x152a/0x2a50 mm/memory.c:6195 handle_mm_fault+0x589/0xd10 mm/memory.c:6364 faultin_page mm/gup.c:1144 [inline] __get_user_pages+0x551/0x34a0 mm/gup.c:1446 __get_user_pages_locked mm/gup.c:1712 [inline] get_dump_page+0x257/0x3d0 mm/gup.c:2212 dump_user_range+0x195/0xb70 fs/coredump.c:1364 elf_core_dump+0x2929/0x3b60 fs/binfmt_elf.c:2085 coredump_write fs/coredump.c:1049 [inline] vfs_coredump+0x2ba2/0x56d0 fs/coredump.c:1168 get_signal+0x22e3/0x26d0 kernel/signal.c:3019 arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:40 [inline] exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] irqentry_exit_to_user_mode+0x12a/0x270 kernel/entry/common.c:73 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621 RIP: 0033:0x0 RSP: 002b:000000000000000a EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007febcb1b6090 RCX: 00007febcaf8ebe9 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000020003b46 RBP: 00007febcb011e19 R08: 0000000000000002 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007febcb1b6128 R14: 00007febcb1b6090 R15: 00007fff3c8f4628 rcu: rcu_preempt kthread starved for 4229 jiffies! g65985 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-syzkaller-12250-gc30a13538d9f #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 5c 65 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d c3 d1 19 00 fb f4 3c 0d 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df8 EFLAGS: 000002c6 RAX: 000000000065ba0b RBX: 0000000000000001 RCX: ffffffff8b903bf9 RDX: 0000000000000000 RSI: ffffffff8de4b9c6 RDI: ffffffff8c162900 RBP: ffffed1003c57b40 R08: 0000000000000001 R09: ffffed10170a6655 R10: ffff8880b85332ab R11: 0000000000000000 R12: 0000000000000001 R13: ffff88801e2bda00 R14: ffffffff90ab6b90 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881247c6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb7a5266e80 CR3: 000000000e380000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148