rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3919/1:b..l P5472/1:b..l P5943/1:b..l (detected by 1, t=10503 jiffies, g=21385, q=45 ncpus=2) task:syz.6.266 state:R running task stack:24864 pid:5943 ppid:5040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_is_held_type+0x13a/0x190 kernel/locking/lockdep.c:5710 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc9000346f030 EFLAGS: 00000206 RAX: 0150386b181be300 RBX: ffff888052ef5940 RCX: 0150386b181be300 RDX: 0000000000000000 RSI: ffffffff8a6c1180 RDI: ffffffff8abf1260 RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff2117049 R10: fffffbfff2117049 R11: 1ffffffff2117048 R12: 0000000000000000 R13: 0000000000000246 R14: ffffffff8c92ab20 R15: ffff888052ef6420 lookup_page_ext mm/page_ext.c:277 [inline] page_ext_get+0x18f/0x2a0 mm/page_ext.c:158 __reset_page_owner+0x31/0x1a0 mm/page_owner.c:144 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384 free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3525 release_pages+0x1f92/0x2200 mm/swap.c:1035 __pagevec_release+0x6d/0xe0 mm/swap.c:1055 pagevec_release include/linux/pagevec.h:71 [inline] folio_batch_release include/linux/pagevec.h:135 [inline] shmem_undo_range+0x75b/0x2050 mm/shmem.c:946 shmem_truncate_range mm/shmem.c:1062 [inline] shmem_evict_inode+0x248/0xa40 mm/shmem.c:1171 evict+0x485/0x870 fs/inode.c:705 __dentry_kill+0x431/0x650 fs/dcache.c:611 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xfa/0x1d0 fs/dcache.c:918 __fput+0x5e0/0x920 fs/file_table.c:328 task_work_run+0x1ca/0x250 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x936/0x2400 kernel/exit.c:871 do_group_exit+0x217/0x2d0 kernel/exit.c:1021 get_signal+0x1272/0x1350 kernel/signal.c:2871 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f9b5d38e969 RSP: 002b:00007f9b5e149038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: 0000000000010106 RBX: 00007f9b5d5b6080 RCX: 00007f9b5d38e969 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000007 RBP: 00007f9b5d410ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f9b5d5b6080 R15: 00007ffc63786f38 task:kworker/u4:21 state:R running task stack:26208 pid:5472 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696 RIP: 0010:debug_lockdep_rcu_enabled+0xb/0x30 kernel/rcu/update.c:280 Code: 6b 8a 48 c7 c6 80 22 6c 8a e8 11 b1 3d f7 0f 0b eb d1 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 31 c0 83 3d 77 4a ef 03 00 74 1d <83> 3d 02 7e ef 03 00 74 14 65 48 8b 0d 54 38 f3 75 31 c0 83 b9 dc RSP: 0018:ffffc90004607bd8 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffff88802eeb05c0 RCX: 6cbfc346a9aa6900 RDX: 0000000000000000 RSI: ffffffff8a6c1180 RDI: ffffffff8abf1260 RBP: ffff888059a8caf0 R08: dffffc0000000000 R09: fffffbfff2117049 R10: fffffbfff2117049 R11: 1ffffffff2117048 R12: dffffc0000000000 R13: ffffffff89d935ce R14: ffff88807c87cc80 R15: 000000000000015e rcu_read_lock include/linux/rcupdate.h:792 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xf4/0x600 net/batman-adv/network-coding.c:719 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 task:dhcpcd state:R running task stack:20960 pid:3919 ppid:3918 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6730 preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6754 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 unwind_next_frame+0x1892/0x20b0 arch/x86/kernel/unwind_orc.c:629 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 save_stack+0xf3/0x1e0 mm/page_owner.c:127 __reset_page_owner+0x51/0x1a0 mm/page_owner.c:148 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479 free_slab mm/slub.c:2031 [inline] discard_slab mm/slub.c:2037 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2586 put_cpu_partial+0x17c/0x250 mm/slub.c:2662 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x123/0x2f0 mm/slub.c:3422 copy_fs_struct+0x4b/0x270 fs/fs_struct.c:114 copy_fs+0x6c/0x140 kernel/fork.c:1614 copy_process+0x1829/0x4060 kernel/fork.c:2257 kernel_clone+0x225/0x8b0 kernel/fork.c:2681 __do_sys_clone kernel/fork.c:2822 [inline] __se_sys_clone kernel/fork.c:2806 [inline] __x64_sys_clone+0x17c/0x1d0 kernel/fork.c:2806 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f6ac2c3d636 RSP: 002b:00007ffd92ade9f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffd92ade9f8 RCX: 00007f6ac2c3d636 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffd92afef40 R08: 0000000000000000 R09: 0000000000000001 R10: 00007f6ac2b69a10 R11: 0000000000000246 R12: 00007ffd92adeb30 R13: 0000000000000000 R14: 0000000000000000 R15: 000055fcda56bac0 rcu: rcu_preempt kthread starved for 10615 jiffies! g21385 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:26912 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 5993 Comm: syz.4.279 Not tainted 6.1.140-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:207 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:147 [inline] RIP: 0010:wrmsr arch/x86/include/asm/msr.h:254 [inline] RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:206 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 df 65 f8 02 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc9000349fcb0 EFLAGS: 00000246 RAX: 00000000000000f6 RBX: ffffffff8c3d0b78 RCX: 000000000000083f RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f RBP: 0000000000000000 R08: dffffc0000000000 R09: fffff52000693f85 R10: fffff52000693f85 R11: 1ffff92000693f84 R12: ffff8880b8f33e01 R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000020 FS: 00007f13b2c376c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c41443d CR3: 0000000041938000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_irq_work_raise+0x82/0xd0 arch/x86/kernel/irq_work.c:31 irq_work_queue+0x95/0x140 kernel/irq_work.c:114 bpf_send_signal_common+0x2b2/0x420 kernel/trace/bpf_trace.c:879 ____bpf_send_signal kernel/trace/bpf_trace.c:888 [inline] bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:886 bpf_prog_7ba5217f62dcd359+0x38/0x3c bpf_dispatcher_nop_func include/linux/bpf.h:1001 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline] bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2324 __bpf_trace_sys_enter+0x60/0x70 include/trace/events/syscalls.h:18 trace_sys_enter+0x6b/0x80 include/trace/events/syscalls.h:18 syscall_trace_enter+0xf0/0x150 kernel/entry/common.c:81 do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:77 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f13b1d2ab39 Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25 RSP: 002b:00007f13b2c36b40 EFLAGS: 00000246 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007f13b1fb5fa8 RCX: 00007f13b1d2ab39 RDX: 00007f13b2c36b40 RSI: 00007f13b2c36c70 RDI: 0000000000000011 RBP: 00007f13b1fb5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f13b1fb5fac R13: 0000000000000000 R14: 00007fffaf0dbfd0 R15: 00007fffaf0dc0b8