rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=d314/1/0x4000000000000000 softirq=90298/90309 fqs=0
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P20025/1:b..l
rcu: 	(detected by 0, t=10506 jiffies, g=82537, q=75 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 36 Comm: kworker/u8:2 Not tainted 6.15.0-syzkaller-09161-g0f70f5b08a47 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:enqueue_hrtimer+0xab/0x3b0 kernel/time/hrtimer.c:1089
Code: 89 e6 e8 c8 45 13 00 45 84 e4 0f 85 38 02 00 00 e8 da 4a 13 00 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 <0f> 85 cc 02 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 23 49 8d 7c
RSP: 0018:ffffc90000a08e18 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffff8880b8527e40 RCX: ffffffff81a8a30f
RDX: 1ffff110170a4fc8 RSI: ffffffff81a8a0c6 RDI: 0000000000000001
RBP: ffff88805e35d340 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffffffff9afe2c60 R12: 0000000000000001
R13: 0000000000000000 R14: ffff88805e35d340 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88812486e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c391f68 CR3: 000000003445f000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __run_hrtimer kernel/time/hrtimer.c:1778 [inline]
 __hrtimer_run_queues+0x8ff/0xad0 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
 __sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1056
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_release+0x183/0x2f0 kernel/locking/lockdep.c:5896
Code: 0f c1 05 a8 ed 32 12 83 f8 01 0f 85 1d 01 00 00 9c 58 f6 c4 02 0f 85 08 01 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 fd ab 32 12 0f 85 58 01 00 00 48 83 c4 18 5b 41 5c 41
RSP: 0018:ffffc90000ac7a70 EFLAGS: 00000206
RAX: 17b0fd8ba3880a00 RBX: ffffffff8e5c4780 RCX: ffffc90000ac7a7c
RDX: 0000000000000002 RSI: ffffffff8dde1904 RDI: ffffffff8c153200
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff8b49a125
R13: 0000000000000206 R14: ffff88801eefa440 R15: 0000000000000003
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:871 [inline]
 batadv_nc_process_nc_paths.part.0+0x21a/0x3e0 net/batman-adv/network-coding.c:699
 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:679 [inline]
 batadv_nc_worker+0xcd3/0x1030 net/batman-adv/network-coding.c:728
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
task:syz.2.4027      state:R  running task     stack:26056 pid:20025 tgid:20016 ppid:15975  task_flags:0x400040 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5392 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6781
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7104
 irqentry_exit+0x36/0x90 kernel/entry/common.c:307
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5875
Code: a6 32 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 d2 0d 0f 0f 0f 82 74 02 00 00 8b 35 ba 3f 0f 0f 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 69 a6 32 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0000:ffffc9000b7f6b20 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e5c4780 RCX: 000000009c22ba9f
RDX: 0000000000000000 RSI: ffffffff8dde1904 RDI: ffffffff8c153200
RBP: 0000000000000002 R08: 437f0b3048eb3a99 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x160/0x1f0 mm/page_owner.c:156
 __set_page_owner+0x91/0x550 mm/page_owner.c:329
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1710
 prep_new_page mm/page_alloc.c:1718 [inline]
 get_page_from_freelist+0x135c/0x3950 mm/page_alloc.c:3680
 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4970
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301
 folio_alloc_mpol_noprof+0x36/0x2f0 mm/mempolicy.c:2320
 vma_alloc_folio_noprof+0xed/0x1e0 mm/mempolicy.c:2355
 folio_prealloc mm/memory.c:1054 [inline]
 wp_page_copy mm/memory.c:3478 [inline]
 do_wp_page+0x1130/0x4f80 mm/memory.c:3939
 handle_pte_fault mm/memory.c:6013 [inline]
 __handle_mm_fault+0x2226/0x5450 mm/memory.c:6140
 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6309
 do_user_addr_fault+0x7a6/0x1370 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x5c/0xb0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:74
Code: cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08 73 e8 eb c5 <f3> a4 c3 cc cc cc cc 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48
RSP: 0000:ffffc9000b7f78f8 EFLAGS: 00050206
RAX: 0000000000000001 RBX: 0000000000001000 RCX: 0000000000000078
RDX: 0000000000000000 RSI: ffff88804e45cf88 RDI: 00002000003cb000
RBP: 0000000000001000 R08: 0000000000000000 R09: ffffed1009c8b9ff
R10: ffff88804e45cfff R11: 0000000000000000 R12: 00000000003c9ff8
R13: ffff888028a9b000 R14: ffff88804e45c000 R15: 00002000003ca078
 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline]
 copy_to_user_iter lib/iov_iter.c:25 [inline]
 iterate_iovec include/linux/iov_iter.h:52 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:302 [inline]
 iterate_and_advance include/linux/iov_iter.h:328 [inline]
 _copy_to_iter+0x4eb/0x16f0 lib/iov_iter.c:185
 copy_page_to_iter lib/iov_iter.c:362 [inline]
 copy_page_to_iter+0x12a/0x1e0 lib/iov_iter.c:349
 copy_folio_to_iter include/linux/uio.h:204 [inline]
 shmem_file_read_iter+0x467/0xac0 mm/shmem.c:3408
 do_iter_readv_writev+0x637/0x820 fs/read_write.c:825
 vfs_readv+0x4cb/0x8b0 fs/read_write.c:1018
 do_preadv+0x1a6/0x270 fs/read_write.c:1132
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3f2898e969
RSP: 002b:00007f3f267f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00007f3f28bb6160 RCX: 00007f3f2898e969
RDX: 0000000000000018 RSI: 00002000000015c0 RDI: 0000000000000005
RBP: 00007f3f28a10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f3f28bb6160 R15: 00007ffdf2a73f98
 </TASK>
rcu: rcu_preempt kthread starved for 10506 jiffies! g82537 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:28376 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5392 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6781
 __schedule_loop kernel/sched/core.c:6859 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6874
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 16426 Comm: kworker/u8:11 Not tainted 6.15.0-syzkaller-09161-g0f70f5b08a47 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xd0b/0x1490 kernel/smp.c:885
Code: e8 8a 12 0c 00 45 85 ed 74 46 48 8b 14 24 49 89 d6 49 89 d5 49 c1 ee 03 41 83 e5 07 4d 01 e6 41 83 c5 03 e8 27 17 0c 00 f3 90 <41> 0f b6 06 41 38 c5 7c 08 84 c0 0f 85 6f 05 00 00 8b 43 08 31 ff
RSP: 0018:ffffc9000ff378a0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b85416a0 RCX: ffffffff81afd49d
RDX: ffff888078242440 RSI: ffffffff81afd479 RDI: 0000000000000005
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000
R13: 0000000000000003 R14: ffffed10170a82d5 R15: ffff8880b843cfc0
FS:  0000000000000000(0000) GS:ffff88812476e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000d29000 CR3: 000000000e382000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052
 on_each_cpu include/linux/smp.h:71 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2660 [inline]
 smp_text_poke_batch_finish+0x27b/0xdb0 arch/x86/kernel/alternative.c:2870
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 jump_label_update+0x376/0x550 kernel/jump_label.c:919
 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate mm/kfence/core.c:850 [inline]
 toggle_allocation_gate+0xfa/0x280 mm/kfence/core.c:842
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>