rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2921/1:b..l P7882/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=26877, q=202 ncpus=2)
task:syz.3.518 state:R running task stack:27016 pid:7882 ppid:5773 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:692
RIP: 0010:lock_acquire+0x208/0x420 kernel/locking/lockdep.c:5758
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 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 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc90004307920 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 5dc987f9777d6900
RDX: 0000000000000000 RSI: ffffffff8acadd60 RDI: ffffffff8b1c9860
RBP: ffffc90004307a28 R08: dffffc0000000000 R09: 1ffffffff2238ea0
R10: dffffc0000000000 R11: fffffbfff2238ea1 R12: 1ffff92000860f30
R13: ffffffff8d132160 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
rcu_read_lock include/linux/rcupdate.h:786 [inline]
__pte_offset_map+0x48/0x2c0 mm/pgtable-generic.c:287
__pte_offset_map_lock+0x47/0x1d0 mm/pgtable-generic.c:371
pte_offset_map_lock include/linux/mm.h:3016 [inline]
wp_page_copy mm/memory.c:3132 [inline]
do_wp_page+0x17de/0x35f0 mm/memory.c:3469
handle_pte_fault mm/memory.c:5063 [inline]
__handle_mm_fault mm/memory.c:5188 [inline]
handle_mm_fault+0x135d/0x4c00 mm/memory.c:5353
do_user_addr_fault+0xac8/0x12c0 arch/x86/mm/fault.c:1322
handle_page_fault arch/x86/mm/fault.c:1463 [inline]
exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7fd0848507fc
RSP: 002b:00007fff2a4b37d8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffff81ec871c RCX: 0000000000000000
RDX: 000000000000071c RSI: ffffffff81ec871c RDI: 0000000000000000
RBP: 0000000000000000 R08: 00007fd084c00000 R09: 00007fd084c02000
R10: 0000000081ec8720 R11: 0000000000000000 R12: 00007fd084c16038
R13: 00000000000000d0 R14: ffffffff81ec867b R15: 00007fd085745720
task:kworker/u4:9 state:R running task stack:22632 pid:2921 ppid:2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lock_acquire+0x208/0x420 kernel/locking/lockdep.c:5758
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 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 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc9000be879c0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: b3e29a44c61a4400
RDX: 0000000000000000 RSI: ffffffff8acadd60 RDI: ffffffff8b1c9860
RBP: ffffc9000be87ad8 R08: dffffc0000000000 R09: 1ffffffff2238ea0
R10: dffffc0000000000 R11: fffffbfff2238ea1 R12: 1ffff920017d0f44
R13: ffffffff8d132160 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
rcu_read_lock include/linux/rcupdate.h:786 [inline]
batadv_nc_process_nc_paths+0xdb/0x390 net/batman-adv/network-coding.c:687
batadv_nc_worker+0x429/0x610 net/batman-adv/network-coding.c:728
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
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 10558 jiffies! g26877 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:27656 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x313/0x1590 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 04/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148
Code: b9 20 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 c3 54 41 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2e 41 89 de 80
RSP: 0018:ffffffff8ce07d80 EFLAGS: 000002c6
RAX: 64d64f09301af700 RBX: ffffffff8162affd RCX: 64d64f09301af700
RDX: 0000000000000001 RSI: ffffffff8acacbe0 RDI: ffffffff8b1c9860
RBP: ffffffff8ce07eb8 R08: ffff8880b8e36b2b R09: 1ffff110171c6d65
R10: dffffc0000000000 R11: ffffed10171c6d66 R12: 1ffffffff19c0fbc
R13: dffffc0000000000 R14: 1ffffffff19d2688 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c27f21d CR3: 000000001da7f000 CR4: 00000000003506f0
Call Trace:
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+0x33d/0x590 kernel/sched/idle.c:302
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401
rest_init+0x2e2/0x300 init/main.c:744
arch_call_rest_init+0xe/0x10 init/main.c:840
start_kernel+0x459/0x4e0 init/main.c:1085
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