rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9296/1:b..l P6044/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=34129, q=803 ncpus=2)
task:kworker/u8:19 state:R running task stack:21080 pid:6044 tgid:6044 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:895 [inline]
RIP: 0010:batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:778 [inline]
RIP: 0010:batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:833 [inline]
RIP: 0010:batadv_iv_ogm_schedule+0x663/0xf00 net/batman-adv/bat_iv_ogm.c:873
Code: 08 4c 89 ef e8 fe 81 03 f7 4d 8b 6d 00 4d 85 ed 74 13 49 81 c5 38 fe ff ff 74 0a e8 a7 25 9d f6 e9 ab fe ff ff e8 9d 25 9d f6 a8 2b 37 00 89 c3 31 ff 89 c6 e8 cd 29 9d f6 85 db 4c 8b a4 24
RSP: 0018:ffffc900051e7840 EFLAGS: 00000293
RAX: ffffffff8b248b54 RBX: 0000000000000001 RCX: ffff8880303d0000
RDX: 0000000000000000 RSI: ffffffff8bc08340 RDI: ffffffff8bc08300
RBP: ffffc900051e7990 R08: ffffffff8b248a80 R09: ffffffff8df41a20
R10: dffffc0000000000 R11: ffffed100d5f9b17 R12: ffff888078d188c0
R13: fffffffffffffe38 R14: dffffc0000000000 R15: ffff8880559e8dd8
batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0 net/batman-adv/bat_iv_ogm.c:1709
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
task:syz.6.925 state:R running task stack:25592 pid:9296 tgid:9291 ppid:6290 task_flags:0x400140 flags:0x00080006
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:118 [inline]
RIP: 0010:lock_acquire+0x8b/0x340 kernel/locking/lockdep.c:5844
Code: 0f 84 d7 01 00 00 83 3d 52 d9 e3 0d 00 0f 84 f0 00 00 00 48 8b b4 24 90 00 00 00 4c 89 ef e8 ac 6d 89 00 83 3d 35 d9 e3 0d 00 <0f> 84 fa 00 00 00 65 8b 05 38 7f e0 10 85 c0 0f 85 eb 00 00 00 65
RSP: 0018:ffffc9000ea9f2b8 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 5f6cfb4c3292cf00
RDX: 0000000000000000 RSI: ffffffff81743fa2 RDI: 1ffffffff1be8344
RBP: ffffffff81743f85 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff81ada120 R12: 0000000000000002
R13: ffffffff8df41a20 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
__call_rcu_common kernel/rcu/tree.c:3119 [inline]
call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3239
slab_free_hook mm/slub.c:2504 [inline]
slab_free mm/slub.c:6668 [inline]
kmem_cache_free+0x488/0x620 mm/slub.c:6779
__io_req_caches_free+0x1c1/0x270 io_uring/io_uring.c:2826
io_queue_deferred+0x81/0x400 io_uring/io_uring.c:520
io_drain_req+0x395/0x550 io_uring/io_uring.c:1753
io_submit_sqe io_uring/io_uring.c:2315 [inline]
io_submit_sqes+0x13a1/0x2140 io_uring/io_uring.c:2434
__do_sys_io_uring_enter io_uring/io_uring.c:3280 [inline]
__se_sys_io_uring_enter+0x2e0/0x2b60 io_uring/io_uring.c:3219
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff1f798f749
RSP: 002b:00007ff1f8834038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007ff1f7be6180 RCX: 00007ff1f798f749
RDX: 0000000000000000 RSI: 00000000000047f6 RDI: 0000000000000009
RBP: 00007ff1f7a13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff1f7be6218 R14: 00007ff1f7be6180 R15: 00007ffc80f9e3c8
rcu: rcu_preempt kthread starved for 10441 jiffies! g34129 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:27152 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
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+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 5e 93 b4 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 93 a0 0c 00 f3 0f 1e fa fb f4 33 93 b4 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8dc07d80 EFLAGS: 000002c6
RAX: 6f16603358650500 RBX: ffffffff81978fda RCX: 6f16603358650500
RDX: 0000000000000001 RSI: ffffffff8d7922ac RDI: ffffffff8bc08360
RBP: ffffffff8dc07ea8 R08: ffff8880b86336db R09: 1ffff110170c66db
R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8f821f70
R13: 1ffffffff1b92a68 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125e35000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2758202043 CR3: 0000000026f6d000 CR4: 0000000000350ef0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1ea/0x520 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
rest_init+0x2de/0x300 init/main.c:757
start_kernel+0x3a7/0x400 init/main.c:1206
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147