rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5823/1:b..l P9061/1:b..l P9054/1:b..l rcu: (detected by 1, t=10503 jiffies, g=299805, q=664 ncpus=2) task:syz.3.5604 state:R running task stack:24432 pid:9054 tgid:9053 ppid:8726 task_flags:0x40044c flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6944 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6968 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:1772 [inline] zap_pmd_range mm/memory.c:1834 [inline] zap_pud_range mm/memory.c:1863 [inline] zap_p4d_range mm/memory.c:1884 [inline] unmap_page_range+0x3a0d/0x4510 mm/memory.c:1905 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1995 exit_mmap+0x283/0xd40 mm/mmap.c:1284 __mmput+0x115/0x420 kernel/fork.c:1356 exit_mm+0x220/0x310 kernel/exit.c:570 do_exit+0x9ad/0x28e0 kernel/exit.c:925 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x168c/0x1720 kernel/signal.c:3036 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1cd5d8d169 RSP: 002b:00007f1cd6b6a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: 0000400000000000 RBX: 00007f1cd5fa5fa0 RCX: 00007f1cd5d8d169 RDX: 000000000100000e RSI: 0000000000b36000 RDI: 0000400000000000 RBP: 00007f1cd5e0e2a0 R08: ffffffffffffffff R09: 0000000000000000 R10: 20c44fb6edc09a38 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f1cd5fa5fa0 R15: 00007f1cd60cfa28 task:sed state:R running task stack:22848 pid:9061 tgid:9061 ppid:9060 task_flags:0x400000 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6944 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6968 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 unwind_next_frame+0x18f8/0x22d0 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660 discard_slab mm/slub.c:2684 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3153 put_cpu_partial+0x17c/0x250 mm/slub.c:3228 __slab_free+0x290/0x380 mm/slub.c:4479 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x23/0xb0 mm/kasan/common.c:385 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4294 [inline] __kmalloc_noprof+0x285/0x4c0 mm/slub.c:4306 kmalloc_noprof include/linux/slab.h:905 [inline] tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x2c0/0x610 security/tomoyo/file.c:822 security_inode_getattr+0x130/0x330 security/security.c:2377 vfs_getattr fs/stat.c:243 [inline] vfs_fstat fs/stat.c:265 [inline] vfs_fstatat+0xa3/0x150 fs/stat.c:366 __do_sys_newfstatat fs/stat.c:532 [inline] __se_sys_newfstatat fs/stat.c:526 [inline] __x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:526 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: 0033:0x7f351b5355f4 RSP: 002b:00007fff17df5598 EFLAGS: 00000206 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007f351b60d460 RCX: 00007f351b5355f4 RDX: 00007fff17df55a0 RSI: 00007f351b5d2130 RDI: 0000000000000003 RBP: 000055ca94a802a0 R08: 0000000000000000 R09: 00007f351b610b70 R10: 0000000000001000 R11: 0000000000000206 R12: 00007fff17df5700 R13: 00007fff17df5700 R14: 000000000000000a R15: 0000000000000000 task:syz-executor state:R running task stack:20592 pid:5823 tgid:5823 ppid:5821 task_flags:0x400100 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7087 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:arch_stack_walk+0xf8/0x150 arch/x86/kernel/stacktrace.c:26 Code: eb 03 48 89 e9 48 8d bd 70 ff ff ff 4c 89 e6 4c 89 fa e8 db c8 09 00 83 bd 70 ff ff ff 00 74 37 48 8d 9d 70 ff ff ff 48 89 df 83 9f 09 00 48 85 c0 74 23 4c 89 f7 48 89 c6 4d 89 eb 41 ff d3 RSP: 0018:ffffc90003f0f760 EFLAGS: 00000202 RAX: 0000000080000001 RBX: ffffc90003f0f760 RCX: 0000000080000000 RDX: dffffc0000000000 RSI: ffffc90003f08000 RDI: ffffc90003f0f760 RBP: ffffc90003f0f7f0 R08: ffffc90003f0fee0 R09: 0000000000000000 R10: ffffc90003f0f7b0 R11: fffff520007e1ef8 R12: ffff88802d563c00 R13: ffffffff81ad4ae0 R14: ffffc90003f0f840 R15: 0000000000000000 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660 discard_slab mm/slub.c:2684 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3153 put_cpu_partial+0x17c/0x250 mm/slub.c:3228 __slab_free+0x290/0x380 mm/slub.c:4479 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] __kmalloc_cache_noprof+0x1d9/0x390 mm/slub.c:4320 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] alloc_pipe_info+0xeb/0x4d0 fs/pipe.c:799 get_pipe_inode fs/pipe.c:891 [inline] create_pipe_files+0x86/0x7d0 fs/pipe.c:923 __do_pipe_flags+0x48/0x2d0 fs/pipe.c:980 do_pipe2+0xd4/0x310 fs/pipe.c:1031 __do_sys_pipe2 fs/pipe.c:1049 [inline] __se_sys_pipe2 fs/pipe.c:1047 [inline] __x64_sys_pipe2+0x5a/0x70 fs/pipe.c:1047 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: 0033:0x7f3c2458be89 RSP: 002b:00007fff6ac62898 EFLAGS: 00000246 ORIG_RAX: 0000000000000125 RAX: ffffffffffffffda RBX: 000055555c74cc40 RCX: 00007f3c2458be89 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 00007fff6ac628a8 RBP: 00007fff6ac62c60 R08: 0000000000000007 R09: 000055555c7639c0 R10: 1023a9dab176f2be R11: 0000000000000246 R12: 000055555c750620 R13: 000055555c751380 R14: 00007fff6ac629e0 R15: 000055555c753298 rcu: rcu_preempt kthread starved for 7557 jiffies! g299805 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:25784 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 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 6.14.0-rc4-syzkaller-00295-gb91872c56940 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:unwind_next_frame+0x334/0x22d0 arch/x86/kernel/unwind_orc.c:505 Code: 00 00 00 00 fc ff df 0f b6 04 28 84 c0 0f 85 58 18 00 00 4c 89 f0 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 6a 18 00 00 0f b6 43 01 <83> e0 07 0f 84 ca 15 00 00 83 f8 01 4c 8b 6c 24 08 49 bc 00 00 00 RSP: 0018:ffffc90000a179f0 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffffffff914890a4 RCX: ffffffff90a65de0 RDX: ffffffff914890a0 RSI: ffffffff914890a0 RDI: 0000000000000001 RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffc90000a17bb0 R10: ffffc90000a17b10 R11: ffffffff81ad4ae0 R12: 0000000000000000 R13: ffffc90000a17ac0 R14: ffffffff914890a5 R15: ffffffff89cd886e FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f351b4b9897 CR3: 000000007d728000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000048e5c DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4171 skb_clone+0x20c/0x390 net/core/skbuff.c:1994 deliver_clone net/bridge/br_forward.c:125 [inline] maybe_deliver+0x96/0x150 net/bridge/br_forward.c:190 br_flood+0x2e4/0x680 net/bridge/br_forward.c:237 br_handle_frame_finish+0x18d2/0x2000 net/bridge/br_input.c:220 br_nf_hook_thresh+0x472/0x590 br_nf_pre_routing_finish_ipv6+0xaa0/0xdd0 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x379/0x770 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:282 [inline] br_handle_frame+0x9f3/0x1530 net/bridge/br_input.c:433 __netif_receive_skb_core+0x13e7/0x4540 net/core/dev.c:5787 __netif_receive_skb_one_core net/core/dev.c:5891 [inline] __netif_receive_skb+0x12f/0x650 net/core/dev.c:6006 process_backlog+0x662/0x15b0 net/core/dev.c:6354 __napi_poll+0xcb/0x490 net/core/dev.c:7188 napi_poll net/core/dev.c:7257 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7379 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 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 80 d6 03 00 48 f7 00 08 00 00 00 75 10 66 90 0f 00 2d 05 f2 81 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: ffff88801da88000 RBX: ffff888145280864 RCX: 0000000000501091 RDX: 0000000000000001 RSI: ffff888145280800 RDI: ffff888145280864 RBP: 000000000003aab8 R08: ffff8880b873799b R09: 1ffff110170e6f33 R10: dffffc0000000000 R11: ffffffff8c089010 R12: ffff8880203b0800 R13: 0000000000000001 R14: 0000000000000001 R15: ffffffff8f337da0 acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:699 cpuidle_enter_state+0x109/0x470 drivers/cpuidle/cpuidle.c:268 cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:389 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x372/0x5c0 kernel/sched/idle.c:325 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423 start_secondary+0x102/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147