rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P14816/1:b..l P16292/1:b..l P16301/1:b..l rcu: (detected by 1, t=10503 jiffies, g=77081, q=351 ncpus=2) task:syz.0.3122 state:R running task stack:23112 pid:16301 tgid:16298 ppid:5865 task_flags:0x400040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 bb 21 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc900208bf0f0 EFLAGS: 00000206 RAX: e7c5c28cfbefce00 RBX: 0000000000000000 RCX: e7c5c28cfbefce00 RDX: 0000000000000001 RSI: ffffffff8dba7696 RDI: ffffffff8be33880 RBP: ffffffff81cea4a6 R08: 0000000000000000 R09: ffffffff81cea4a6 R10: dffffc0000000000 R11: ffffffff81ac3aa0 R12: 0000000000000002 R13: ffffffff8e139f20 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] is_bpf_text_address+0x47/0x2b0 kernel/bpf/core.c:776 kernel_text_address+0xa5/0xe0 kernel/extable.c:125 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x71/0x1f0 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+0xdbd/0x1520 mm/page_alloc.c:2952 folios_put_refs+0x559/0x640 mm/swap.c:997 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1157 shmem_truncate_range mm/shmem.c:1269 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1397 evict+0x504/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 __fput+0x68e/0xa70 fs/file_table.c:476 fput_close_sync+0x119/0x200 fs/file_table.c:573 __do_sys_close fs/open.c:1587 [inline] __se_sys_close fs/open.c:1572 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1572 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa1ced8d84a RSP: 002b:00007fa1ccfcce00 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007fa1ced8d84a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000215 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000005 R13: 00007fa1ccfccef0 R14: 00007fa1ccfcceb0 R15: 00007fa1c4a00000 task:syz.3.3119 state:R running task stack:25736 pid:16292 tgid:16291 ppid:5867 task_flags:0x400040 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:-1 [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_acquire+0xd2/0x360 kernel/locking/lockdep.c:5864 Code: 00 65 48 8b 04 25 08 80 a0 92 83 b8 ec 0a 00 00 00 0f 85 d5 00 00 00 48 c7 44 24 30 00 00 00 00 9c 8f 44 24 30 4c 89 74 24 10 <4d> 89 fe 4c 8b 7c 24 30 fa 48 c7 c7 05 be 9c 8d e8 a9 84 dc 09 65 RSP: 0018:ffffc90020337868 EFLAGS: 00000246 RAX: ffff888067c28000 RBX: 0000000000000000 RCX: 3c8a02cae7ee7f00 RDX: 0000000000000000 RSI: ffffffff820ff2e5 RDI: 1ffffffff1c273e4 RBP: ffffffff820ff2c9 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed100cf85001 R12: 0000000000000002 R13: ffffffff8e139f20 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] ___pte_offset_map+0x45/0x250 mm/pgtable-generic.c:286 __pte_offset_map include/linux/mm.h:3014 [inline] __pte_offset_map_lock+0x46/0x210 mm/pgtable-generic.c:397 pte_offset_map_lock include/linux/mm.h:3029 [inline] follow_page_pte+0xc4/0x13e0 mm/gup.c:826 follow_pmd_mask mm/gup.c:-1 [inline] follow_pud_mask mm/gup.c:981 [inline] follow_p4d_mask mm/gup.c:998 [inline] follow_page_mask mm/gup.c:1041 [inline] __get_user_pages+0xa8e/0x2ce0 mm/gup.c:1444 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1880 __mm_populate+0x24c/0x380 mm/gup.c:1983 mm_populate include/linux/mm.h:3367 [inline] vm_mmap_pgoff+0x387/0x4d0 mm/util.c:585 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0d5598ebe9 RSP: 002b:00007f0d53bee038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f0d55bc5fa0 RCX: 00007f0d5598ebe9 RDX: 000000000300000e RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f0d55a11e19 R08: ffffffffffffffff R09: 0000000000000000 R10: 20c44fb6edc09a38 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0d55bc6038 R14: 00007f0d55bc5fa0 R15: 00007ffcc703d498 task:kworker/u8:18 state:R running task stack:22312 pid:14816 tgid:14816 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 bb 21 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9001f937910 EFLAGS: 00000206 RAX: 7cfed7e30b201400 RBX: 0000000000000000 RCX: 7cfed7e30b201400 RDX: 0000000000000000 RSI: ffffffff8dba7696 RDI: ffffffff8be33880 RBP: ffffffff8b47c4aa R08: 0000000000000000 R09: ffffffff8b47c4aa R10: dffffc0000000000 R11: fffffbfff1f47207 R12: 0000000000000002 R13: ffffffff8e139f20 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_nc_process_nc_paths+0xdb/0x3a0 net/batman-adv/network-coding.c:687 batadv_nc_worker+0x429/0x610 net/batman-adv/network-coding.c:728 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 7294 jiffies! g77081 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:26792 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 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 syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 3e 7d 96 f5 cc cc cc 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 73 67 0e 00 f3 0f 1e fa fb f4 13 7d 96 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c2 RAX: 68734d7b98678d00 RBX: ffffffff819683c8 RCX: 68734d7b98678d00 RDX: 0000000000000001 RSI: ffffffff8d9b8241 RDI: ffffffff8be33880 RBP: ffffc90000197f20 R08: ffff8880b8732f9b R09: 1ffff110170e65f3 R10: dffffc0000000000 R11: ffffed10170e65f4 R12: ffffffff8fa39030 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff1100395db40 FS: 0000000000000000(0000) GS:ffff888125d18000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000023000 CR3: 000000005659e000 CR4: 0000000000350ef0 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+0x74/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147 hrtimer: interrupt took 1744128001 ns