rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P21325/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=182209, q=279 ncpus=2)
task:kworker/u4:7 state:R running task stack:25000 pid:21325 ppid:2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
preempt_schedule_notrace+0xce/0x110 kernel/sched/core.c:6959
preempt_schedule_notrace_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:46
rcu_is_watching+0x7a/0xb0 kernel/rcu/tree.c:701
rcu_read_lock include/linux/rcupdate.h:787 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0x10c/0x610 net/batman-adv/network-coding.c:719
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
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 10507 jiffies! g182209 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:27496 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x99/0x380 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5773 Comm: sshd-session Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:unwind_next_frame+0xd4/0x2970 arch/x86/kernel/unwind_orc.c:482
Code: 4c 89 74 24 60 48 89 5c 24 18 bf 01 00 00 00 e8 92 c6 20 00 49 8d 6c 24 50 48 89 e8 48 c1 e8 03 48 89 44 24 50 42 80 3c 28 00 <74> 08 48 89 ef e8 22 3f a2 00 4c 8b 75 00 4d 85 f6 74 44 49 81 c6
RSP: 0018:ffffc90000006e78 EFLAGS: 00000246
RAX: 1ffff92000000df3 RBX: 1ffff92000000de9 RCX: ffffffff96ead403
RDX: ffff88802a72bc00 RSI: 0000000000000002 RDI: 0000000000000001
RBP: ffffc90000006f98 R08: ffffc90000007010 R09: 0000000000000012
R10: 0000000000000004 R11: 0000000000000100 R12: ffffc90000006f48
R13: dffffc0000000000 R14: ffffc90000006f80 R15: ffffffff886cad80
FS: 00007fb4ed18c300(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2dc21ff8 CR3: 000000007b354000 CR4: 00000000003506f0
Call Trace:
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1811 [inline]
slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
kmem_cache_free+0xf8/0x280 mm/slub.c:3852
enqueue_to_backlog+0x1d2/0xe30 net/core/dev.c:4882
netif_rx_internal+0x119/0x4e0 net/core/dev.c:5138
netif_rx+0x59/0x90 net/core/dev.c:5191
vxcan_xmit+0x47b/0x770 drivers/net/can/vxcan.c:73
__netdev_start_xmit include/linux/netdevice.h:4943 [inline]
netdev_start_xmit include/linux/netdevice.h:4957 [inline]
xmit_one net/core/dev.c:3619 [inline]
dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3635
__dev_queue_xmit+0x1a64/0x35a0 net/core/dev.c:4425
dev_queue_xmit include/linux/netdevice.h:3113 [inline]
can_send+0x805/0xb60 net/can/af_can.c:277
can_can_gw_rcv+0xbed/0xec0 net/can/gw.c:563
deliver net/can/af_can.c:573 [inline]
can_rcv_filter+0x120/0x7a0 net/can/af_can.c:600
can_receive+0x312/0x440 net/can/af_can.c:664
canfd_rcv+0x145/0x270 net/can/af_can.c:703
__netif_receive_skb_one_core net/core/dev.c:5608 [inline]
__netif_receive_skb+0xcc/0x290 net/core/dev.c:5722
process_backlog+0x380/0x6e0 net/core/dev.c:6050
__napi_poll+0xc0/0x460 net/core/dev.c:6612
napi_poll net/core/dev.c:6679 [inline]
net_rx_action+0x5ea/0xbf0 net/core/dev.c:6815
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 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:_compound_head include/linux/page-flags.h:248 [inline]
RIP: 0010:virt_to_folio include/linux/mm.h:1291 [inline]
RIP: 0010:virt_to_slab mm/slab.h:218 [inline]
RIP: 0010:qlink_to_cache+0x1c/0xb0 mm/kasan/quarantine.c:129
Code: 41 5e 41 5f 5d e9 d4 fa 9a 08 0f 1f 40 00 e8 0b 12 5f ff 48 c1 e8 06 48 83 e0 c0 48 ba 00 00 00 00 00 ea ff ff 48 8b 4c 10 08 c1 01 75 7e 48 01 d0 66 90 48 8b 48 08 f6 c1 01 75 42 66 90 48
RSP: 0018:ffffc900043bf6d8 EFLAGS: 00000206
RAX: 0000000000c280c0 RBX: ffffc900043bf718 RCX: ffffea0000c28001
RDX: ffffea0000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888030a03a60 R08: 0000000000000001 R09: 0000000000000000
R10: ffff88801efd9450 R11: fffffbfff21b4ca6 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888030a03a60
qlist_free_all+0x39/0xe0 mm/kasan/quarantine.c:182
kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
slab_alloc_node mm/slub.c:3495 [inline]
kmem_cache_alloc_node+0x150/0x330 mm/slub.c:3540
__alloc_skb+0x108/0x2c0 net/core/skbuff.c:640
alloc_skb_fclone include/linux/skbuff.h:1334 [inline]
tcp_stream_alloc_skb+0x3d/0x330 net/ipv4/tcp.c:872
tcp_sendmsg_locked+0xed2/0x4af0 net/ipv4/tcp.c:1154
tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1344
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
sock_write_iter+0x2bb/0x3f0 net/socket.c:1160
call_write_iter include/linux/fs.h:2018 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x43b/0x940 fs/read_write.c:584
ksys_write+0x147/0x250 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb4ecaa7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffdf94a7060 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb4ed18c300 RCX: 00007fb4ecaa7407
RDX: 000000000000001c RSI: 0000558d0f4f9590 RDI: 0000000000000004
RBP: 0000558d0f4fd0c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000558d08f615d9
R13: 0000558d08f73190 R14: 0000558d0f4fc840 R15: 0000000000000003