rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12/1:b..l P1087/1:b..l P5156/1:b..l P1068/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=11097, q=534 ncpus=2)
task:kworker/u4:5 state:R running task stack:22952 pid:1068 ppid:2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009
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:check_kcov_mode kernel/kcov.c:193 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp4+0x36/0x90 kernel/kcov.c:287
Code: 70 23 7e 7e 65 8b 0d 71 23 7e 7e 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75 5b 83 ba 1c 16 00 00 00 74 52 8b 8a f8 15 00 00 <83> f9 03 75 47 48 8b 8a 00 16 00 00 44 8b 8a fc 15 00 00 49 c1 e1
RSP: 0018:ffffc900043fee40 EFLAGS: 00000246
RAX: ffffffff8450fef0 RBX: 00000000000000ec RCX: 0000000000000000
RDX: ffff88802352bc00 RSI: 00000000000000f0 RDI: 0000000000000b7c
RBP: 0000000000000002 R08: 000027260000ffff R09: 000003e80000650e
R10: 000027260000ffff R11: 000003e80000650e R12: 0000000000000b7c
R13: dffffc0000000000 R14: ffff888077113640 R15: 00000000000000f0
nla_reserve+0xb0/0x1b0 lib/nlattr.c:969
inet6_fill_ifla6_attrs+0x272/0x21b0 net/ipv6/addrconf.c:5785
inet6_fill_link_af+0x9b/0x120 net/ipv6/addrconf.c:5834
rtnl_fill_link_af+0x1c2/0x430 net/core/rtnetlink.c:1701
rtnl_fill_ifinfo+0x1ab4/0x1d60 net/core/rtnetlink.c:1931
rtmsg_ifinfo_build_skb+0x18e/0x260 net/core/rtnetlink.c:4072
rtmsg_ifinfo_event net/core/rtnetlink.c:4106 [inline]
rtmsg_ifinfo+0x8c/0x1a0 net/core/rtnetlink.c:4115
register_netdevice+0x1710/0x1ae0 net/core/dev.c:10327
nsim_init_netdevsim drivers/net/netdevsim/netdev.c:343 [inline]
nsim_create+0x3ca/0x4a0 drivers/net/netdevsim/netdev.c:401
__nsim_dev_port_add+0x702/0xb00 drivers/net/netdevsim/dev.c:1393
nsim_dev_port_add_all+0x35/0xe0 drivers/net/netdevsim/dev.c:1449
nsim_dev_reload_create drivers/net/netdevsim/dev.c:1501 [inline]
nsim_dev_reload_up+0x455/0x770 drivers/net/netdevsim/dev.c:988
devlink_reload+0x2c1/0x600 net/devlink/dev.c:400
devlink_pernet_pre_exit+0x18a/0x340 net/devlink/core.c:288
ops_pre_exit_list net/core/net_namespace.c:163 [inline]
cleanup_net+0x57f/0xb90 net/core/net_namespace.c:632
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
task:udevd state:R running task stack:25160 pid:5156 ppid:1 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866
preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xfa/0x110 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
__wake_up_common_lock kernel/sched/wait.c:140 [inline]
__wake_up_sync_key+0x11f/0x190 kernel/sched/wait.c:213
sock_def_readable+0x1e1/0x430 net/core/sock.c:3354
__netlink_sendskb net/netlink/af_netlink.c:1266 [inline]
netlink_sendskb+0x9b/0x130 net/netlink/af_netlink.c:1272
netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
___sys_sendmsg+0x220/0x290 net/socket.c:2649
__sys_sendmsg net/socket.c:2678 [inline]
__do_sys_sendmsg net/socket.c:2687 [inline]
__se_sys_sendmsg+0x1a5/0x270 net/socket.c:2685
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: 0033:0x7f0aaaca7407
RSP: 002b:00007fffd1b483c0 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f0aab3bd880 RCX: 00007f0aaaca7407
RDX: 0000000000000000 RSI: 00007fffd1b48420 RDI: 0000000000000004
RBP: 0000562381ca2190 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000081
R13: 0000562381afe9e0 R14: 0000000000000000 R15: 0000000000000000
task:kworker/u4:6 state:R running task stack:24304 pid:1087 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
task:kworker/u4:1 state:R running task stack:23728 pid:12 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009
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:PagePoisoned include/linux/page-flags.h:297 [inline]
RIP: 0010:page_to_nid include/linux/mm.h:1647 [inline]
RIP: 0010:page_zone include/linux/mm.h:1861 [inline]
RIP: 0010:folio_zone include/linux/mm.h:1871 [inline]
RIP: 0010:zone_stat_mod_folio include/linux/vmstat.h:439 [inline]
RIP: 0010:__folio_start_writeback+0x84c/0xf80 mm/page-writeback.c:3060
Code: 0a e2 ce ff 4d 85 f6 75 16 e8 00 e2 ce ff eb 15 e8 f9 e1 ce ff e8 04 6f b8 08 4d 85 f6 74 ea e8 ea e1 ce ff fb 48 8b 44 24 20 <42> 80 3c 28 00 74 08 48 89 df e8 c5 4f 26 00 48 89 5c 24 08 4c 8b
RSP: 0018:ffffc90000116bc0 EFLAGS: 00000293
RAX: 1ffffd40003b5100 RBX: ffffea0001da8800 RCX: ffff88801ba55a00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000116d38 R08: ffffffff90da95a7 R09: 1ffffffff21b52b4
R10: dffffc0000000000 R11: fffffbfff21b52b5 R12: ffffea0001da8808
R13: dffffc0000000000 R14: 0000000000000200 R15: 0000000000000000
ext4_bio_write_folio+0xedc/0x2250 fs/ext4/page-io.c:566
mpage_submit_folio+0x237/0x3c0 fs/ext4/inode.c:1908
mpage_map_and_submit_buffers fs/ext4/inode.c:2154 [inline]
mpage_map_and_submit_extent fs/ext4/inode.c:2293 [inline]
ext4_do_writepages+0x1d01/0x38d0 fs/ext4/inode.c:2718
ext4_writepages+0x1a8/0x2f0 fs/ext4/inode.c:2807
do_writepages+0x3a2/0x600 mm/page-writeback.c:2575
__writeback_single_inode+0x153/0xee0 fs/fs-writeback.c:1635
writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1926
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:1997
wb_writeback+0x464/0xba0 fs/fs-writeback.c:2107
wb_check_old_data_flush fs/fs-writeback.c:2211 [inline]
wb_do_writeback fs/fs-writeback.c:2264 [inline]
wb_workfn+0xabc/0xe20 fs/fs-writeback.c:2292
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 10553 jiffies! g11097 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:26568 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:2168
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:
CPU: 1 PID: 5959 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 00 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 2a b2 ee f6 48 89 df e8 42 84 ef f6 e8 1d 2b 13 f7 fb bf 01 00 00 00 12 a6 e2 f6 65 8b 05 03 ed 8a 75 85 c0 74 02 5b c3 e8 e0 d2 87
RSP: 0018:ffffc900035b7c78 EFLAGS: 00000286
RAX: ea80667cde278300 RBX: ffff88806d801bc0 RCX: ea80667cde278300
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: 0000000000000001
RBP: ffff88806d802058 R08: ffffffff8e4a93ef R09: 1ffffffff1c9527d
R10: dffffc0000000000 R11: fffffbfff1c9527e R12: 1ffff1100db0040b
R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000
FS: 000055557d9e5500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000001ebdd000 CR4: 00000000003506e0
Call Trace:
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x11f5/0x1400 kernel/signal.c:2905
arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa46f38f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff0d4b9428 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fa46f5e5fa0 RCX: 00007fa46f38f749
RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fa46f413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa46f5e5fa0 R14: 00007fa46f5e5fa0 R15: 0000000000000004