rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4496/1:b..l P11/1:b..l
(detected by 1, t=10502 jiffies, g=15953, q=106 ncpus=2)
task:kworker/u4:1 state:R running task stack:23248 pid:11 ppid:2 flags:0x00004000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x225/0x4a0 kernel/locking/lockdep.c:5666
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f0 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 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc90000107920 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 9766b587aedbc700
RDX: 0000000000000000 RSI: ffffffff8a8c23a0 RDI: ffffffff8adf0c20
RBP: ffffc90000107a28 R08: dffffc0000000000 R09: 1ffffffff215e648
R10: dffffc0000000000 R11: fffffbfff215e649 R12: 0000000000000001
R13: 1ffff92000020f30 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [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+0x407/0xf10 net/batman-adv/bat_iv_ogm.c:868
batadv_iv_send_outstanding_bat_ogm_packet+0x72f/0x840 net/batman-adv/bat_iv_ogm.c:1712
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
task:udevd state:R running task stack:24912 pid:4496 ppid:3637 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6731
preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6755
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
_raw_spin_unlock_irq+0x3c/0x40 kernel/locking/spinlock.c:202
spin_unlock_irq include/linux/spinlock.h:401 [inline]
loop_queue_work drivers/block/loop.c:894 [inline]
loop_queue_rq+0x9d9/0xac0 drivers/block/loop.c:1874
__blk_mq_issue_directly block/blk-mq.c:2643 [inline]
__blk_mq_try_issue_directly+0x46d/0x7f0 block/blk-mq.c:2696
blk_mq_request_issue_directly block/blk-mq.c:2730 [inline]
blk_mq_plug_issue_direct+0x233/0x620 block/blk-mq.c:2750
blk_mq_flush_plug_list+0x6d8/0xc50 block/blk-mq.c:2850
__blk_flush_plug+0x3e0/0x460 block/blk-core.c:1179
blk_finish_plug+0x59/0x80 block/blk-core.c:1203
read_pages+0x658/0x850 mm/readahead.c:184
page_cache_ra_unbounded+0x690/0x770 mm/readahead.c:270
do_page_cache_ra mm/readahead.c:300 [inline]
force_page_cache_ra mm/readahead.c:331 [inline]
page_cache_sync_ra+0x3d7/0x490 mm/readahead.c:713
page_cache_sync_readahead include/linux/pagemap.h:1250 [inline]
filemap_get_pages mm/filemap.c:2665 [inline]
filemap_read+0x646/0x3020 mm/filemap.c:2759
blkdev_read_iter+0x42d/0x570 block/fops.c:668
call_read_iter include/linux/fs.h:2259 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x4a7/0xa00 fs/read_write.c:470
ksys_read+0x14c/0x250 fs/read_write.c:613
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fea028a7407
RSP: 002b:00007ffc5cc84240 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fea03051880 RCX: 00007fea028a7407
RDX: 0000000000000200 RSI: 00007fea03045000 RDI: 0000000000000009
RBP: 0000561b9811d050 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000fb6200 R14: 0000561b981256f8 R15: 00007fea0317839c
rcu: rcu_preempt kthread starved for 10563 jiffies! g15953 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:28016 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742
Code: 48 89 df e8 a7 10 9d f7 e9 44 ff ff ff e8 7d 07 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d 87 5d 50 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffc90000177de8 EFLAGS: 000002c6
RAX: 90cb5dbc3212c600 RBX: ffffffff8a3651a7 RCX: 90cb5dbc3212c600
RDX: 0000000000000001 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0c20
RBP: ffffc90000177f20 R08: ffff8880b8f3580b R09: 1ffff110171e6b01
R10: dffffc0000000000 R11: ffffed10171e6b02 R12: 1ffff9200002efc8
R13: dffffc0000000000 R14: ffff888017739dc0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fea03046000 CR3: 000000005b8eb000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
default_idle_call+0x84/0xc0 kernel/sched/idle.c:109
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x20d/0x5a0 kernel/sched/idle.c:303
cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401
start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281
secondary_startup_64_no_verify+0xcf/0xdb