rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5194/1:b..l P7362/1:b..l rcu: (detected by 1, t=10502 jiffies, g=25477, q=389 ncpus=2) task:syz.2.391 state:R running task stack:24104 pid:7362 tgid:7360 ppid:5851 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090 task:syslogd state:R running task stack:23624 pid:5194 tgid:5194 ppid:1 task_flags:0x400000 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_notrace+0x103/0x140 kernel/sched/core.c:7040 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x7e/0xb0 kernel/rcu/tree.c:737 rcu_read_lock include/linux/rcupdate.h:842 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xe7/0x23b0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x11a/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:4161 [inline] slab_alloc_node mm/slub.c:4210 [inline] kmem_cache_alloc_noprof+0x1e1/0x390 mm/slub.c:4217 kmem_alloc_batch lib/debugobjects.c:371 [inline] fill_pool+0x262/0x690 lib/debugobjects.c:403 debug_objects_fill_pool lib/debugobjects.c:725 [inline] debug_object_activate+0x4c1/0x5c0 lib/debugobjects.c:814 debug_rcu_head_queue kernel/rcu/rcu.h:224 [inline] __call_rcu_common kernel/rcu/tree.c:3067 [inline] call_rcu+0x99/0xad0 kernel/rcu/tree.c:3202 __slab_free+0x2c6/0x390 mm/slub.c:4567 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:4341 [inline] __kmalloc_noprof+0x28e/0x4d0 mm/slub.c:4353 kmalloc_noprof include/linux/slab.h:909 [inline] tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x2be/0x640 security/tomoyo/file.c:822 security_inode_getattr+0x130/0x330 security/security.c:2377 vfs_getattr fs/stat.c:256 [inline] vfs_fstat fs/stat.c:278 [inline] vfs_fstatat+0xa5/0x150 fs/stat.c:370 __do_sys_newfstatat fs/stat.c:536 [inline] __se_sys_newfstatat fs/stat.c:530 [inline] __x64_sys_newfstatat+0x11f/0x1a0 fs/stat.c:530 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3046dc25f4 RSP: 002b:00007ffc04bacfc8 EFLAGS: 00000206 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 000056167fe6f910 RCX: 00007f3046dc25f4 RDX: 00007ffc04bacff0 RSI: 00007f3046e5f130 RDI: 0000000000000003 RBP: 00007ffc04bad0d0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000001000 R11: 0000000000000206 R12: 000056167fe6fc50 R13: 000000006805c051 R14: 0000000000000004 R15: 000056167fe6fa60 rcu: rcu_preempt kthread starved for 5446 jiffies! g25477 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:26376 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 7385 Comm: syz-executor Not tainted 6.15.0-rc2-syzkaller-00488-g6fea5fabd332 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:32 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline] RIP: 0010:lock_release+0xb0/0x3e0 kernel/locking/lockdep.c:5883 Code: bd ec 0a 00 00 00 0f 85 ae 01 00 00 48 c7 c0 d0 f6 2b 94 49 39 07 0f 84 9e 01 00 00 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 <4c> 8b 74 24 20 fa 48 c7 c7 f8 56 50 8e e8 0e 47 91 0a 65 ff 05 47 RSP: 0018:ffffc90000006ad8 EFLAGS: 00000206 RAX: ffffffff942bf6d0 RBX: ffffffff93686020 RCX: ffff8880213cbc00 RDX: 0000000000000100 RSI: ffffffff8ca1b660 RDI: ffffffff8ca1b620 RBP: ffffffff8af71fb3 R08: ffffffff8af72521 R09: ffffffff8a35dd8c R10: 0000000000000004 R11: ffff8880213cbc00 R12: ffffffff93686020 R13: ffff8880213cbc00 R14: 0000000000000001 R15: ffffffff8ed3df20 FS: 00005555847ea500(0000) GS:ffff888124f9a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000001dc030 CR3: 000000007e50e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] nf_hook include/linux/netfilter.h:271 [inline] NF_HOOK+0x68c/0x780 include/linux/netfilter.h:312 br_nf_forward_ip+0x61e/0x7b0 net/bridge/br_netfilter_hooks.c:719 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc8/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x2ac/0x460 include/linux/netfilter.h:312 __br_forward+0x46a/0x640 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xb3/0x150 net/bridge/br_forward.c:190 br_flood+0x2e4/0x680 net/bridge/br_forward.c:237 br_handle_frame_finish+0x185b/0x1f60 net/bridge/br_input.c:220 br_nf_hook_thresh+0x482/0x5a0 net/bridge/br_netfilter_hooks.c:1170 br_nf_pre_routing_finish_ipv6+0xaa3/0xdd0 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x397/0x790 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+0x9fa/0x1530 net/bridge/br_input.c:433 __netif_receive_skb_core+0x155a/0x4bb0 net/core/dev.c:5773 __netif_receive_skb_one_core net/core/dev.c:5885 [inline] __netif_receive_skb+0x130/0x670 net/core/dev.c:6000 process_backlog+0x664/0x15c0 net/core/dev.c:6352 __napi_poll+0xcb/0x480 net/core/dev.c:7324 napi_poll net/core/dev.c:7388 [inline] net_rx_action+0x89d/0x1240 net/core/dev.c:7510 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xfb/0x220 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 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:__rcu_read_unlock+0x75/0x110 kernel/rcu/tree_plugin.h:441 Code: 85 ed 75 21 4d 8d be 48 04 00 00 4c 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 88 00 00 00 41 83 3f 00 75 29 42 0f b6 04 23 <84> c0 75 62 41 8b 45 00 3d 00 00 00 40 73 0f 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90003567530 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff11004279808 RCX: 0000000000000003 RDX: dffffc0000000000 RSI: ffffffff8e4db4c4 RDI: ffffffff8ca1b680 RBP: 0000000000000000 R08: ffffc90003567cb0 R09: 0000000000000000 R10: ffffc90003567690 R11: fffff520006aced4 R12: dffffc0000000000 R13: ffff8880213cc044 R14: ffff8880213cbc00 R15: ffff8880213cc048 rcu_read_unlock include/linux/rcupdate.h:873 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x1aa4/0x23b0 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122 save_stack+0xfc/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x1e0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] __free_frozen_pages+0xde8/0x10a0 mm/page_alloc.c:2725 discard_slab mm/slub.c:2730 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3199 put_cpu_partial+0x17e/0x250 mm/slub.c:3274 __slab_free+0x294/0x390 mm/slub.c:4526 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:4341 [inline] __kmalloc_noprof+0x28e/0x4d0 mm/slub.c:4353 kmalloc_noprof include/linux/slab.h:909 [inline] kmalloc_array_noprof include/linux/slab.h:948 [inline] security_inode_init_security+0x12e/0x490 security/security.c:1829 shmem_symlink+0x169/0x610 mm/shmem.c:4099 vfs_symlink+0x137/0x2e0 fs/namei.c:4723 do_symlinkat+0x228/0x3d0 fs/namei.c:4749 __do_sys_symlinkat fs/namei.c:4765 [inline] __se_sys_symlinkat fs/namei.c:4762 [inline] __x64_sys_symlinkat+0x95/0xb0 fs/namei.c:4762 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f78dc18d6e7 Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0a 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f78dc4dfda8 EFLAGS: 00000202 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f78dc18d6e7 RDX: 00007f78dc2122c8 RSI: 00000000ffffff9c RDI: 00007f78dc4dfe40 RBP: 00007f78dc4dfdec R08: 0000000000000017 R09: 00007f78dc4dfaf7 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000053 R13: 00000000000927c0 R14: 0000000000036abd R15: 00007f78dc4dfe40 net_ratelimit: 8507 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:78:4d:36:78:3b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:78:4d:36:78:3b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 12134 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:78:4d:36:78:3b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ea:78:4d:36:78:3b, vlan:0)