rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4439/1:b..l P5407/1:b..l (detected by 1, t=10502 jiffies, g=14869, q=227) task:syz.9.240 state:R running task stack:25056 pid: 5407 ppid: 5071 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6780 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627 Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b RSP: 0018:ffffc9000396eac0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: de21a96b8d3c9b00 RDX: 0000000000000000 RSI: ffffffff8a0b2460 RDI: ffffffff8a59a700 RBP: ffffc9000396ebe0 R08: dffffc0000000000 R09: fffffbfff1ff3619 R10: fffffbfff1ff3619 R11: 1ffffffff1ff3618 R12: ffffffff8c11c060 R13: 1ffff9200072dd64 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] is_bpf_text_address+0x1d/0x270 kernel/bpf/core.c:725 kernel_text_address kernel/extable.c:151 [inline] __kernel_text_address+0x9a/0x100 kernel/extable.c:105 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 save_stack+0xf3/0x1e0 mm/page_owner.c:119 __set_page_owner+0x41/0x2d0 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5466 alloc_pages_vma+0x393/0x7c0 mm/mempolicy.c:2146 shmem_alloc_page mm/shmem.c:1586 [inline] shmem_alloc_and_acct_page+0x427/0xb70 mm/shmem.c:1611 shmem_getpage_gfp+0x14f4/0x2d40 mm/shmem.c:1906 shmem_fault+0x1a9/0x520 mm/shmem.c:2118 __do_fault+0x141/0x330 mm/memory.c:3928 do_read_fault mm/memory.c:4264 [inline] do_fault mm/memory.c:4392 [inline] handle_pte_fault mm/memory.c:4650 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x2949/0x43c0 mm/memory.c:4883 faultin_page mm/gup.c:976 [inline] __get_user_pages+0x93e/0x11c0 mm/gup.c:1197 populate_vma_page_range+0x213/0x290 mm/gup.c:1529 __mm_populate+0x26f/0x3a0 mm/gup.c:1638 mm_populate include/linux/mm.h:2632 [inline] vm_mmap_pgoff+0x203/0x2b0 mm/util.c:556 ksys_mmap_pgoff+0x140/0x780 mm/mmap.c:1623 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fce3ab40969 RSP: 002b:00007fce389a8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fce3ad67fa0 RCX: 00007fce3ab40969 RDX: b635773f06ebbeef RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007fce3abc2ab1 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fce3ad67fa0 R15: 00007ffe93993798 task:kworker/u4:13 state:R running task stack:23584 pid: 4439 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6780 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681 RIP: 0010:rcu_is_watching+0x63/0xa0 kernel/rcu/tree.c:1124 Code: 89 f7 e8 00 9b 59 00 48 c7 c3 c8 b2 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 2b 8b 03 65 ff 0d 95 d3 9e 7e <74> 08 24 01 5b 41 5e 41 5f c3 e8 56 de 9c ff eb f1 48 c7 c7 e0 0c RSP: 0000:ffffc900031df8e0 EFLAGS: 00000286 RAX: 00000000001b23f9 RBX: ffff8880b903b2c8 RCX: 1edc81d5baffb100 RDX: 0000000000000000 RSI: ffffffff8a59a6e0 RDI: ffffffff8a59a6a0 RBP: ffffc900031dfa20 R08: dffffc0000000000 R09: fffffbfff1ad1556 R10: fffffbfff1ad1556 R11: 1ffffffff1ad1555 R12: ffffffff8c11c060 R13: 1ffff9200063bf2c R14: ffffffff8bbaf810 R15: dffffc0000000000 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0xcd/0x3f0 kernel/locking/lockdep.c:5594 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:754 [inline] batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:825 [inline] batadv_iv_ogm_schedule+0x432/0xe90 net/batman-adv/bat_iv_ogm.c:868 batadv_iv_send_outstanding_bat_ogm_packet+0x72d/0x840 net/batman-adv/bat_iv_ogm.c:1712 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: rcu_preempt kthread timer wakeup didn't happen for 10586 jiffies! g14869 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=9305 rcu: rcu_preempt kthread starved for 10592 jiffies! g14869 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27848 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5403 Comm: syz.7.238 Not tainted 5.15.184-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__unsafe_setup_sigcontext arch/x86/kernel/signal.c:184 [inline] RIP: 0010:__setup_rt_frame arch/x86/kernel/signal.c:485 [inline] RIP: 0010:setup_rt_frame arch/x86/kernel/signal.c:780 [inline] RIP: 0010:handle_signal arch/x86/kernel/signal.c:824 [inline] RIP: 0010:arch_do_signal_or_restart+0xc4e/0x1300 arch/x86/kernel/signal.c:869 Code: 08 00 74 08 4c 89 ef e8 70 db 93 00 49 8b 45 00 49 89 87 b8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 40 80 3c 01 00 <4c> 8b 6c 24 30 74 08 4c 89 ef e8 43 db 93 00 41 0f b7 45 00 66 41 RSP: 0018:ffffc9000391fcc0 EFLAGS: 00040246 RAX: dffffc0000000000 RBX: ffffc9000391ff58 RCX: 1ffff92000723ffc RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000391fec0 R08: 0000000000000000 R09: fffffbfff1775e66 R10: fffffbfff1775e66 R11: 1ffffffff1775e60 R12: 0000000000000000 R13: ffffc9000391ffe8 R14: ffffc9000391ffd8 R15: 00007fdbaa50eb38 FS: 00007fdbaa50f6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdbaa50f650 CR3: 00000000561aa000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fdbac9e9967 Code: ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 <0f> 05 48 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 RSP: 002b:00007fdbaa50f0e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007fdbacc11088 RCX: 00007fdbac9e9969 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fdbacc11088 RBP: 00007fdbacc11080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdbacc1108c R13: 0000000000000000 R14: 00007ffd6795cbd0 R15: 00007ffd6795ccb8