rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12/1:b..l
P30854/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=151233, q=1246 ncpus=2)
task:udevd state:R running task
stack:26248 pid:30854 tgid:30854 ppid:5221 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5314 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6697
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7020
irqentry_exit+0x6f/0x90 kernel/entry/common.c:196
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 5b 1b 4b 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90003f876f8 EFLAGS: 00000206
RAX: fbc5ac9b8ac12100 RBX: 0000000000000000 RCX: fbc5ac9b8ac12100
RDX: 0000000000000001 RSI: ffffffff8de8034c RDI: ffffffff8c04d240
RBP: ffffffff823cfcc6 R08: 0000000000000000 R09: ffffffff823cfcc6
R10: 000000000000002f R11: 0000000000000000 R12: 0000000000000002
R13: ffffffff8e53c5a0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
__d_lookup+0x83/0x780 fs/dcache.c:2390
lookup_fast+0x84/0x5b0 fs/namei.c:1766
walk_component fs/namei.c:2125 [inline]
link_path_walk+0x642/0xea0 fs/namei.c:2497
path_openat+0x28c/0x3830 fs/namei.c:4042
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3913ea7407
RSP: 002b:00007fffa14161c0 EFLAGS: 00000202
ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f391460c880 RCX: 00007f3913ea7407
RDX: 0000000000080000 RSI: 00007fffa14162f0 RDI: ffffffffffffff9c
RBP: 0000558c7c621e20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000558c7c621f10
R13: 00007fffa14162f0 R14: 00007fffa1418d00 R15: 0000558c58913bcc
task:kworker/u8:0 state:R
running task stack:23304 pid:12 tgid:12 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5314 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6697
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7020
irqentry_exit+0x6f/0x90 kernel/entry/common.c:196
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 5b 1b 4b 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90000117980 EFLAGS: 00000206
RAX: b0013b553120b300 RBX: 0000000000000000 RCX: b0013b553120b300
RDX: 0000000000000000 RSI: ffffffff8de8034c RDI: ffffffff8c04d240
RBP: ffffffff8b4f1112 R08: 0000000000000000 R09: ffffffff8b4f1112
R10: dffffc0000000000 R11: fffffbfff1fc9ba7 R12: 0000000000000002
R13: ffffffff8e53c5a0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719
process_one_work kernel/workqueue.c:3239 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3322
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 2982 jiffies! g151233 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5314 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6697
__schedule_loop kernel/sched/core.c:6775 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6790
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2062
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2264
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 1085 Comm: syz.2.4179 Not tainted 6.16.0-rc5-next-20250711-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:869
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 a6 6a 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 51 66 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 35 66
RSP: 0018:ffffc90004fcf340 EFLAGS: 00000293
RAX: ffffffff81b4a15b RBX: 1ffff110170e7f69 RCX: ffff8880677c1e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90004fcf4c0 R08: ffffffff8fe4dd37 R09: 1ffffffff1fc9ba6
R10: dffffc0000000000 R11: fffffbfff1fc9ba7 R12: ffff8880b873fb48
R13: dffffc0000000000 R14: ffff8880b863b200 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88812578f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000928000 CR3: 000000000e336000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 00000000be70000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1036
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x6b1/0x12c0 arch/x86/mm/tlb.c:1451
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline]
tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403
tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
free_ldt_pgtables+0x17b/0x320 arch/x86/kernel/ldt.c:411
arch_exit_mmap arch/x86/include/asm/mmu_context.h:234 [inline]
exit_mmap+0x17c/0xb50 mm/mmap.c:1269
__mmput+0x118/0x420 kernel/fork.c:1120
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x648/0x2300 kernel/exit.c:947
do_group_exit+0x21c/0x2d0 kernel/exit.c:1100
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f96fdf8e929
Code: Unable to access opcode bytes at 0x7f96fdf8e8ff.
RSP: 002b:00007f96fedf0038 EFLAGS: 00000246
ORIG_RAX: 000000000000013e
RAX: 0000000000928000 RBX: 00007f96fe1b5fa0 RCX: 00007f96fdf8e929
RDX: 0000000000000000 RSI: 00000000ffffff9a RDI: 0000200000000240
RBP: 00007f96fe010b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f96fe1b5fa0 R15: 00007ffd79a13bd8