rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4361/1:b..l P5009/1:b..l
	(detected by 0, t=10502 jiffies, g=12397, q=15)
task:syz.3.159       state:R  running task     stack:24984 pid: 5009 ppid:  4185 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777
 irqentry_exit+0x53/0x80 kernel/entry/common.c:432
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681
RIP: 0010:rcu_lockdep_current_cpu_online+0xfc/0x130 kernel/rcu/tree.c:1175
Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 2a 32 5f 00 49 f7 06 01 00 00 00 75 04 31 c0 eb 02 b0 01 65 ff 0d ec 33 97 7e <74> 08 5b 41 5c 41 5e 41 5f c3 e8 cd 50 95 ff eb f1 48 c7 c7 e0 44
RSP: 0018:ffffc9000341f698 EFLAGS: 00000286
RAX: 1ffffffff1964701 RBX: ffffffff8cb23cf0 RCX: 0000000080000000
RDX: ffff888026208000 RSI: ffffffff8af9f2a0 RDI: ffff8880b8f3b198
RBP: 0000000000000001 R08: ffffffff843aae37 R09: fffffbfff2131821
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000002
R13: ffff888070cf4002 R14: ffffffff8cb23c80 R15: dffffc0000000000
 rcu_read_lock_held_common kernel/rcu/update.c:112 [inline]
 rcu_read_lock_held+0x1a/0x40 kernel/rcu/update.c:309
 xa_head include/linux/xarray.h:1166 [inline]
 xas_start+0x2d7/0x7b0 lib/xarray.c:188
 xas_load+0x28/0x140 lib/xarray.c:233
 mapping_get_entry mm/filemap.c:1826 [inline]
 pagecache_get_page+0x20f/0x1010 mm/filemap.c:1894
 shmem_getpage_gfp+0x36c/0x3190 mm/shmem.c:1841
 shmem_getpage mm/shmem.c:151 [inline]
 shmem_write_begin+0xce/0x1a0 mm/shmem.c:2474
 generic_perform_write+0x2bf/0x5b0 mm/filemap.c:3785
 __generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3912
 generic_file_write_iter+0xa7/0x1b0 mm/filemap.c:3944
 call_write_iter include/linux/fs.h:2174 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0xacd/0xe50 fs/read_write.c:594
 ksys_write+0x1a2/0x2c0 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f820893cc1f
RSP: 002b:00007f82067a6df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f820893cc1f
RDX: 0000000001000000 RSI: 00007f81fe387000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000009654
R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000003
R13: 00007f82067a6ef0 R14: 00007f82067a6eb0 R15: 00007f81fe387000
 </TASK>
task:kworker/u4:9    state:R  running task     stack:21144 pid: 4361 ppid:     2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777
 irqentry_exit+0x53/0x80 kernel/entry/common.c:432
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681
RIP: 0010:batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:413 [inline]
RIP: 0010:batadv_nc_worker+0x154/0x5b0 net/batman-adv/network-coding.c:723
Code: be e5 02 00 00 48 c7 c2 20 8b bf 8b e8 05 06 47 f7 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 0f 47 ae f7 48 8b 1b <48> 85 db 74 50 48 81 c3 38 fe ff ff 74 47 4c 89 f7 48 89 de 48 c7
RSP: 0018:ffffc90003dafbf8 EFLAGS: 00000246
RAX: 1ffff1100fcaf970 RBX: 0000000000000000 RCX: ffff88802a703b80
RDX: 0000000000000000 RSI: ffffffff8af9f2a0 RDI: ffffffff8af9f260
RBP: 0000000000000001 R08: ffffffff8a1c2661 R09: fffffbfff2131821
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000170
R13: dffffc0000000000 R14: ffff88802a350c80 R15: ffff888021ae7ac0
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: rcu_preempt kthread starved for 10563 jiffies! g12397 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:27064 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 5019 Comm: syz.2.164 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619
 update_process_times+0x196/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1688 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__syscall_enter_from_user_work kernel/entry/common.c:93 [inline]
RIP: 0010:syscall_enter_from_user_mode+0x37/0x240 kernel/entry/common.c:114
Code: 49 89 fe 48 8b 7c 24 30 e8 46 f6 ff ff e9 8d 01 00 00 e9 91 01 00 00 e8 87 ab 47 f7 e8 72 a9 47 f7 fb 65 4c 8b 3d 39 15 c3 75 <49> 8b 5f 08 f6 c3 3f 0f 84 ce 00 00 00 f6 c3 20 74 17 4c 89 f7 e8
RSP: 0018:ffffc900031afef8 EFLAGS: 00000282
RAX: 3217a11a0b306100 RBX: ffffc900031aff30 RCX: ffffffff96a92f03
RDX: dffffc0000000000 RSI: ffffffff8aab2b80 RDI: ffffffff8af9f2c0
RBP: ffffc900031aff48 R08: ffffffff81870420 R09: fffffbfff1c150ee
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: 0000000000000027 R14: ffffc900031aff58 R15: ffff888074420000
 do_syscall_64+0x1e/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f97c0daa127
Code: 0b e9 68 fe ff ff 48 83 c4 18 48 8d 3d 72 87 d5 00 5b 5d 41 5c 41 5d 41 5e 41 5f e9 13 f8 fb ff 0f 1f 00 b8 27 00 00 00 0f 05 <c3> 0f 1f 84 00 00 00 00 00 b8 6e 00 00 00 0f 05 c3 0f 1f 84 00 00
RSP: 002b:00007f97bec1bb08 EFLAGS: 00000202 ORIG_RAX: 0000000000000027
RAX: ffffffffffffffda RBX: 00007f97bec1bc70 RCX: 00007f97c0daa127
RDX: 00007f97bec1bb40 RSI: 00007f97bec1bc70 RDI: 0000000000000021
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007f97c0fcbfac
R13: 0000000000000000 R14: 00007ffe4d78b600 R15: 00007ffe4d78b6e8
 </TASK>