rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6231/1:b..l P6207/1:b..l
(detected by 1, t=10503 jiffies, g=25053, q=24 ncpus=2)
task:kworker/u4:20 state:R running task stack:26336 pid:6207 ppid:2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
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+0x20f/0x490 kernel/locking/lockdep.c:5666
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 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 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc90006327a40 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 512e372e3a1b6700
RDX: 0000000000000000 RSI: ffffffff8a8c1680 RDI: ffffffff8adefce0
RBP: ffffc90006327b58 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: 0000000000000000
R13: 1ffff92000c64f54 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
batadv_nc_process_nc_paths+0xdb/0x390 net/batman-adv/network-coding.c:687
batadv_nc_worker+0x527/0x600 net/batman-adv/network-coding.c:735
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 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:24032 pid:6231 ppid:3638 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
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:nd_jump_root+0x1/0x410 fs/namei.c:957
Code: 00 00 48 3b 44 24 60 75 0f 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 cc 92 34 08 66 2e 0f 1f 84 00 00 00 00 00 66 90 55 <41> 57 41 56 41 55 41 54 53 48 89 fb 49 bc 00 00 00 00 00 fc ff df
RSP: 0018:ffffc9000673f8e8 EFLAGS: 00000246
RAX: ffffffff81e2a975 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88802f498000 RSI: 0000000000000000 RDI: ffffc9000673fc20
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: 1ffff1100fe46004
R13: 0000000000000040 R14: ffffc9000673fc20 R15: dffffc0000000000
path_init+0x3e5/0x1200 fs/namei.c:2389
path_openat+0x187/0x2e70 fs/namei.c:3778
do_filp_open+0x1c1/0x3c0 fs/namei.c:3810
do_sys_openat2+0x142/0x490 fs/open.c:1318
do_sys_open fs/open.c:1334 [inline]
__do_sys_openat fs/open.c:1350 [inline]
__se_sys_openat fs/open.c:1345 [inline]
__x64_sys_openat+0x135/0x160 fs/open.c:1345
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7faf791e2407
RSP: 002b:00007ffe09a85060 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007faf79156880 RCX: 00007faf791e2407
RDX: 0000000000080241 RSI: 00007ffe09a855c0 RDI: ffffffffffffff9c
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000001b6 R11: 0000000000000202 R12: 0000563bb6c9bdfc
R13: 0000563bb6c9bdfc R14: 0000000000000001 R15: 0000563bf020a430
rcu: rcu_preempt kthread starved for 10564 jiffies! g25053 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:27840 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x95/0x380 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6916 Comm: syz.0.902 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:common_interrupt_return+0x1b/0x5d arch/x86/entry/entry_64.S:617
Code: e8 2a 52 d7 ff e9 f5 02 00 00 0f 1f 44 00 00 66 90 b9 48 00 00 00 65 48 8b 14 25 68 6f 02 00 83 e2 fe 89 d0 48 c1 ea 20 0f 30 <41> 5f 41 5e 41 5d 41 5c 5d 5b 41 5b 41 5a 41 59 41 58 58 59 5a 5e
RSP: 0018:ffffc90004cbff58 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000048
RDX: 0000000000000000 RSI: ffffffff8a8c0500 RDI: ffffffff8adefce0
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1c3eee6
R10: fffffbfff1c3eee6 R11: 00007f57695b7600 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f576a4b06c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 00000000762bb000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
RIP: 0033:0x7f57695b7600
Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d ca 3c 08 00 e8 d5 8e f8 ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48
RSP: 002b:00007f576a4afb38 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f57697e5fa8 RCX: 00007f576958eec9
RDX: 00007f576a4afb40 RSI: 00007f576a4afc70 RDI: 0000000000000021
RBP: 00007f57697e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f57697e6038 R14: 00007fff52b14c80 R15: 00007fff52b14d68