rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=22673, q=423908 ncpus=2)
task:kworker/u4:0 state:R running task stack:21784 pid:11 ppid:2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7011
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:692
RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:80 [inline]
RIP: 0010:rcu_is_watching+0x9/0xb0 kernel/rcu/tree.c:699
Code: 80 1e 09 48 c7 c7 40 89 13 8d 4c 89 f6 e8 3f cf f5 02 e9 44 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 41 57 41 56 53 <65> ff 05 68 6e 92 7e e8 cb 95 1e 09 89 c3 83 f8 08 73 60 49 bf 00
RSP: 0018:ffffc90000107b40 EFLAGS: 00000202
RAX: ffffffff8a571689 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff88801b65bc00 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000000 R08: dffffc0000000000 R09: 1ffffffff223dea0
R10: dffffc0000000000 R11: fffffbfff223dea1 R12: dffffc0000000000
R13: ffffffff8a571562 R14: ffff88805ebf4d00 R15: 00000000000000a6
rcu_read_unlock include/linux/rcupdate.h:815 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
batadv_nc_worker+0x202/0x600 net/batman-adv/network-coding.c:719
process_one_work kernel/workqueue.c:2657 [inline]
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: rcu_preempt kthread starved for 10409 jiffies! g22673 f0x2 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:27848 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:240 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp8+0x8/0x80 kernel/kcov.c:289
Code: 08 04 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d 70 33 7c 7e 65 8b 15 71 33 7c 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc90000007550 EFLAGS: 00000202
RAX: ffffffff813bd0c5 RBX: ffffc90000000001 RCX: ffffc90000007768
RDX: ffffffff8ce93400 RSI: ffffc900000076c0 RDI: ffffc90000007760
RBP: 0000000000000002 R08: ffffffff8ce93440 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000100 R12: ffffc900000076c0
R13: ffffc90000007628 R14: ffffc90000007760 R15: ffffc90000007638
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007feccccd97a3 CR3: 0000000076aa9000 CR4: 00000000003506f0
Call Trace:
unwind_next_frame+0x1cf5/0x2990 arch/x86/kernel/unwind_orc.c:-1
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1811 [inline]
slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
kmem_cache_free+0xf8/0x290 mm/slub.c:3852
llc_rcv+0x743/0xc60 net/llc/llc_input.c:-1
__netif_receive_skb_one_core net/core/dev.c:5670 [inline]
__netif_receive_skb+0xcc/0x290 net/core/dev.c:5784
process_backlog+0x380/0x710 net/core/dev.c:6112
__napi_poll+0xbb/0x460 net/core/dev.c:6674
napi_poll net/core/dev.c:6741 [inline]
net_rx_action+0x65f/0xcc0 net/core/dev.c:6877
handle_softirqs+0x27d/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148
Code: b9 19 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 63 76 38 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2c 89 cb 80 f9
RSP: 0018:ffffffff8ce07d80 EFLAGS: 000002c2
RAX: a870ad84b0599400 RBX: ffffffff81631c41 RCX: a870ad84b0599400
RDX: 0000000000000001 RSI: ffffffff8acacce0 RDI: ffffffff8b1d35e0
RBP: ffffffff8ce07eb8 R08: ffff8880b8e36b6b R09: 1ffff110171c6d6d
R10: dffffc0000000000 R11: ffffed10171c6d6e R12: 1ffffffff19c0fbc
R13: dffffc0000000000 R14: 1ffffffff19d2688 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:753
default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
cpuidle_idle_call kernel/sched/idle.c:178 [inline]
do_idle+0x221/0x5c0 kernel/sched/idle.c:302
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401
rest_init+0x2e2/0x300 init/main.c:705
arch_call_rest_init+0xe/0x10 init/main.c:801
start_kernel+0x461/0x4e0 init/main.c:1046
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536
secondary_startup_64_no_verify+0x179/0x17b