From: syzbot ci <syzbot+cic4f1f7c33eb59a01@syzkaller.appspotmail.com>
To: chenguang.zhao@linux.dev, davem@davemloft.net,
dsahern@kernel.org, edumazet@google.com, horms@kernel.org,
idosch@nvidia.com, kerneljasonxing@gmail.com, kuba@kernel.org,
netdev@vger.kernel.org, pabeni@redhat.com,
syzbot@syzkaller.appspotmail.com, zhaochenguang@kylinos.cn
Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com
Subject: [syzbot ci] Re: ipvs: fix infinite loop with ipvlan L3 from unconditional ipvs_property clear
Date: Sat, 26 Sep 2026 13:12:28 -0700 [thread overview]
Message-ID: <6ab8272c.dc2998a4.2261f5.0058.GAE@google.com> (raw)
In-Reply-To: <20260924063312.1194019-1-chenguang.zhao@linux.dev>
syzbot ci has tested the following series
[v1] ipvs: fix infinite loop with ipvlan L3 from unconditional ipvs_property clear
https://lore.kernel.org/all/20260924063312.1194019-1-chenguang.zhao@linux.dev
* [PATCH net] ipvs: fix infinite loop with ipvlan L3 from unconditional ipvs_property clear
and found the following issue:
INFO: task hung in netdev_run_todo
Full report is available here:
https://ci.syzbot.org/series/b6478e5d-791e-4d72-8b8d-0fa748c90168
***
INFO: task hung in netdev_run_todo
tree: net
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net.git
base: e7e0a54300a896e731dffd3e2e8dae5631d6243d
arch: amd64
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config: https://ci.syzbot.org/builds/9865431b-add2-4883-97e2-de4ec60d969e/config
INFO: task syz-executor:31961 blocked for more than 144 seconds.
Not tainted syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:26120 pid:31961 tgid:31961 ppid:1 task_flags:0x40054c flags:0x00080003
Call Trace:
<TASK>
__schedule+0x17db/0x58f0
schedule+0x164/0x2b0
schedule_preempt_disabled+0x13/0x30
__mutex_lock+0x7c1/0x1550
rcu_barrier+0x4c/0x530
netdev_run_todo+0x2fc/0x1060
tun_chr_close+0x13c/0x1c0
__fput+0x418/0xa50
task_work_run+0x1d9/0x270
do_exit+0x73a/0x2360
do_group_exit+0x22d/0x2f0
get_signal+0x121b/0x12c0
arch_do_signal_or_restart+0xbb/0x860
exit_to_user_mode_loop+0x10e/0x770
do_syscall_64+0x328/0x520
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4b2cf9ddeb
RSP: 002b:00007ffedfbd6b60 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007ffedfbd6c10 RCX: 00007f4b2cf9ddeb
RDX: 00007ffedfbd6be0 RSI: 00000000400454ca RDI: 00000000000000c8
RBP: 00007f4b2d0359ad R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffedfbd6f08 R15: 0000000000000000
</TASK>
Showing all locks held in the system:
locks held by kworker/u8:1/13: 3, on CPU#1:
#0: ffff88817721b940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
#1: ffffc90000127c40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
#2: ffffffff90253600 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
locks held by khungtaskd/35: 1, last CPU#1:
#0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
locks held by getty/5419: 2, on CPU#1:
#0: ffff88817a7b30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
#1: ffffc900027682e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
locks held by kworker/u8:4/9945: 2, last CPU#1:
#0: ffff888177d09940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
#1: ffffc90006db7c40 ((work_completion)(&(&bat_priv->tt.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
locks held by kworker/u8:5/19085: 4, last CPU#1:
#0: ffff88817741f940 ((wq_completion)krds_cp_wq#12/0){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
#1: ffffc90003a0fc40 ((work_completion)(&(&cp->cp_conn_w)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
#2: ffff888169e6a180 (&tc->t_conn_path_lock){+.+.}-{4:4}, at: rds_tcp_conn_path_connect+0x1cc/0x920
#3: ffff888192303660 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: rds_tcp_tune+0x220/0x920
locks held by kworker/u10:0/25329: 3, on CPU#1:
#0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
#1: ffffc9000418fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
#2: ffffffff90253600 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
locks held by kworker/0:1/27790: 7, last CPU#0:
#0: ffff88810006a940 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
#1: ffffc9000141fc40 ((work_completion)(&(&br->gc_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
#2: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: process_backlog+0x3de/0x18b0
#3: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: NF_HOOK+0x9e/0x3c0
#4: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: ip_route_output_key_hash+0xd8/0x2a0
#5: ffff888121028298 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_rearm_deferred+0x99/0x4b0
#6: ffffffff9aa29748 (&____s->seqcount#2){----}-{0:0}, at: __ip_vs_conn_in_get+0x2db/0x10f0
locks held by syz.0.7664/31917: 1, on CPU#1:
#0: ffffffff90253600 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
locks held by syz.3.7666/31925: 1, on CPU#1:
#0: ffffffff8ed62b38 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530
locks held by syz.2.7668/31938: 1, on CPU#1:
#0: ffffffff8ed62b38 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530
locks held by syz-executor/31955: 1, on CPU#1:
#0: ffffffff8ed62b38 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530
locks held by syz-executor/31961: 1, on CPU#1:
#0: ffffffff8ed62b38 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530
locks held by kworker/u8:7/31997: 4, on CPU#1:
#0: ffff8881012d5940 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
#1: ffffc900079cfc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
#2: ffffffff90244da8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810
#3: ffffffff90253600 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x28e/0x8d0
locks held by syz-executor/31998: 1, on CPU#1:
#0: ffffffff8ed62b38 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530
locks held by syz-executor/32005: 1, on CPU#1:
#0: ffffffff90253600 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
locks held by syz-executor/32009: 1, last CPU#1:
#0: ffffffff90253600 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
locks held by syz-executor/32074: 1, on CPU#1:
#0: ffffffff90253600 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30
locks held by syz-executor/32077: 1, on CPU#1:
#0: ffffffff90253600 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30
locks held by syz-executor/32095: 2, last CPU#1:
#0: ffff88816f5b1d38 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0
#1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240
locks held by syz-executor/32096: 1, on CPU#1:
#0: ffffffff90253600 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x470/0x19f0
locks held by syz-executor/32103: 1, on CPU#1:
#0: ffffffff90253600 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x470/0x19f0
locks held by syz-executor/32108: 1, on CPU#1:
#0: ffffffff90253600 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x470/0x19f0
locks held by syz-executor/32116: 2, last CPU#1:
#0: ffff88817a26d038 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0
#1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 35 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150
nmi_cpu_backtrace+0x274/0x2d0
nmi_trigger_cpumask_backtrace+0x17d/0x390
sys_info+0x135/0x170
watchdog+0xfd7/0x1030
kthread+0x38b/0x480
ret_from_fork+0x514/0xb70
ret_from_fork_asm+0x1a/0x30
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 27790 Comm: kworker/0:1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events_long br_fdb_cleanup
RIP: 0010:lock_acquire+0x232/0x350
Code: ff ff ff e8 50 28 42 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 a2 e3 f1 11 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 bf 2c 45 0a cc 48 8d 3d 67 4e da
RSP: 0018:ffffc90000006dc0 EFLAGS: 00000296
RAX: 32f582729c8e9900 RBX: 0000000000000000 RCX: 8000000000000100
RDX: 00000000071bee9f RSI: ffffffff8e69ca38 RDI: ffffffff8c6da580
RBP: ffff888112a39e00 R08: ffffffff8177f1df R09: 0000000000000000
R10: ffffc90000006ef8 R11: ffffffff81b28790 R12: ffffffff8ed5c8a0
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000246
FS: 0000000000000000(0000) GS:ffff88818d6cf000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000040 CR3: 000000000eb48000 CR4: 00000000000006f0
Call Trace:
<IRQ>
unwind_next_frame+0xac/0x2550
arch_stack_walk+0x11b/0x150
stack_trace_save+0xa9/0x100
kasan_save_track+0x3e/0x80
__kasan_slab_alloc+0x6c/0x80
kmem_cache_alloc_node_noprof+0x354/0x610
__alloc_skb+0x1db/0x7a0
synproxy_send_client_synack+0x175/0xde0
nft_synproxy_eval_v4+0x362/0x4e0
nft_synproxy_do_eval+0x335/0x550
nft_do_chain+0x132b/0x1b10
nft_do_chain_ipv4+0x195/0x290
nf_hook_slow+0xc5/0x220
NF_HOOK+0x21f/0x3c0
NF_HOOK+0x336/0x3c0
process_backlog+0xa6b/0x18b0
__napi_poll+0xaa/0x330
net_rx_action+0x61d/0xf50
handle_softirqs+0x226/0x860
__irq_exit_rcu+0xcb/0x220
irq_exit_rcu+0x9/0x30
sysvec_apic_timer_interrupt+0xa6/0xc0
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:lock_acquire+0x232/0x350
Code: ff ff ff e8 50 28 42 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 a2 e3 f1 11 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 bf 2c 45 0a cc 48 8d 3d 67 4e da
RSP: 0018:ffffc9000141faa0 EFLAGS: 00000296
RAX: 32f582729c8e9900 RBX: 0000000000000001 RCX: 0000000000000046
RDX: 000000004abe915d RSI: ffffffff8e69ca38 RDI: ffffffff8c6da580
RBP: ffff888112a39e00 R08: ffffffff818f9aba R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff20f4830 R12: ffffc9000141fc40
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000246
process_scheduled_works+0xc03/0x1630
worker_thread+0xa47/0xfb0
kthread+0x38b/0x480
ret_from_fork+0x514/0xb70
ret_from_fork_asm+0x1a/0x30
</TASK>
***
If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syzbot@syzkaller.appspotmail.com
---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.
To test a fix for this bug, please reply with `#syz test`
(on a separate line) and attach the patch to the email.
Notes:
- The patch will be applied on top of the tested series (as an
incremental fix).
- To test a new version of the whole series, please send it directly
to syzbot@lists.linux.dev.
- Arguments like custom git repos and branches are not supported.
next prev parent reply other threads:[~2026-09-26 20:12 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-24 6:33 [PATCH net] ipvs: fix infinite loop with ipvlan L3 from unconditional ipvs_property clear Chenguang Zhao
2026-09-25 12:42 ` Ido Schimmel
2026-09-28 6:55 ` Chenguang Zhao
2026-09-28 8:10 ` Julian Anastasov
2026-09-26 20:12 ` syzbot ci [this message]
2026-09-28 6:58 ` netdev-bot+sashiko
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