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INFO: task hung in l2tp_eth_delete (2)

Status: auto-obsoleted due to no activity on 2025/04/24 20:33
Subsystems: net
[Documentation on labels]
First crash: 210d, last: 210d
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in l2tp_eth_delete net 1 3 301d 329d 0/29 auto-obsoleted due to no activity on 2025/01/24 08:39

Sample crash report:
INFO: task kworker/u8:29:6063 blocked for more than 140 seconds.
      Not tainted 6.13.0-syzkaller-04057-g15a901361ec3 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:29   state:D stack:24048 pid:6063  tgid:6063  ppid:2      flags:0x00004000
Workqueue: l2tp l2tp_session_del_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5373 [inline]
 __schedule+0x186c/0x4be0 kernel/sched/core.c:6760
 __schedule_loop kernel/sched/core.c:6837 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6852
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6909
 __mutex_lock_common kernel/locking/mutex.c:662 [inline]
 __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730
 unregister_netdevice include/linux/netdevice.h:3329 [inline]
 l2tp_eth_delete+0xdb/0x100 net/l2tp/l2tp_eth.c:155
 l2tp_session_del_work+0x738/0x870 net/l2tp/l2tp_core.c:1745
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317
 worker_thread+0x870/0xd30 kernel/workqueue.c:3398
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
 #0: ffffffff8e93f8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline]
 #0: ffffffff8e93f8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:996
1 lock held by khungtaskd/30:
 #0: ffffffff8e93a3e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e93a3e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e93a3e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
3 locks held by kworker/0:2/973:
 #0: ffff88801ac81d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff88801ac81d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317
 #1: ffffc90003ca7c60 ((crda_timeout).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc90003ca7c60 ((crda_timeout).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317
 #2: ffffffff8fcc5a88 (rtnl_mutex){+.+.}-{4:4}, at: crda_timeout_work+0x15/0x50 net/wireless/reg.c:540
3 locks held by kworker/u8:6/1166:
 #0: ffff88814cfde948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff88814cfde948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317
 #1: ffffc9000423fc60 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc9000423fc60 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317
 #2: ffffffff8fcc5a88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline]
 #2: ffffffff8fcc5a88 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4730
3 locks held by kworker/1:2/2151:
1 lock held by syslogd/5188:
1 lock held by klogd/5195:
4 locks held by udevd/5206:
2 locks held by getty/5584:
 #0: ffff88814e4c80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032fb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5818:
2 locks held by syz-executor/5828:
 #0: ffff88807d248d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:480 [inline]
 #0: ffff88807d248d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2677
 #1: ffff88807d248078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x5c8/0x11c0 net/bluetooth/hci_sync.c:5185
2 locks held by syz-executor/5829:
1 lock held by syz-executor/5830:
 #0: ffffffff8fcc5a88 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:702 [inline]
 #0: ffffffff8fcc5a88 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3521
1 lock held by syz-executor/5832:
2 locks held by syz-executor/5841:
2 locks held by kworker/u8:25/6055:
4 locks held by kworker/u8:29/6063:
 #0: ffff88814d0c6948 ((wq_completion)l2tp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff88814d0c6948 ((wq_completion)l2tp){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317
 #1: ffffc9000552fc60 ((work_completion)(&session->del_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc9000552fc60 ((work_completion)(&session->del_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317
 #2: ffffffff8fcc5a88 (rtnl_mutex){+.+.}-{4:4}, at: l2tp_eth_delete+0x1f/0x100 net/l2tp/l2tp_eth.c:152
 #3: ffffffff8e93f8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline]
 #3: ffffffff8e93f8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:996
7 locks held by kworker/u8:30/6065:
1 lock held by dhcpcd-run-hook/6165:
3 locks held by kworker/0:8/6166:
 #0: ffff88801ac81d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff88801ac81d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317
 #1: ffffc9000459fc60 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc9000459fc60 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317
 #2: ffffffff8fcc5a88 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x99/0xfb0 net/wireless/reg.c:2480
5 locks held by syz-executor/6168:
2 locks held by kworker/1:8/6170:
1 lock held by syz-executor/6172:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-syzkaller-04057-g15a901361ec3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:234 [inline]
 watchdog+0xff6/0x1040 kernel/hung_task.c:397
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5841 Comm: syz-executor Not tainted 6.13.0-syzkaller-04057-g15a901361ec3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:_compound_head include/linux/page-flags.h:244 [inline]
RIP: 0010:virt_to_folio include/linux/mm.h:1297 [inline]
RIP: 0010:virt_to_slab mm/slab.h:211 [inline]
RIP: 0010:qlink_to_cache mm/kasan/quarantine.c:131 [inline]
RIP: 0010:qlist_free_all+0x4a/0x140 mm/kasan/quarantine.c:176
Code: 00 00 00 00 00 ea ff ff 31 ed 4d 89 f4 4c 89 fb 4d 85 ff 75 38 4c 89 e7 e8 53 42 47 ff 48 c1 e8 06 48 83 e0 c0 49 8b 4c 05 08 <f6> c1 01 0f 85 a8 00 00 00 4c 01 e8 66 90 0f b6 48 33 c1 e1 18 81
RSP: 0018:ffffc9000409f338 EFLAGS: 00000202
RAX: 000000000816ed40 RBX: 0000000000000000 RCX: ffffea000816ec01
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff814d557c R09: ffffffff820612cf
R10: dffffc0000000000 R11: fffffbfff285eb0f R12: ffff888205bb5000
R13: ffffea0000000000 R14: ffff888205bb5000 R15: 0000000000000000
FS:  0000555561cf3500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe2bc8d8740 CR3: 000000003459c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4119 [inline]
 slab_alloc_node mm/slub.c:4168 [inline]
 __do_kmalloc_node mm/slub.c:4297 [inline]
 __kmalloc_node_noprof+0x23c/0x4d0 mm/slub.c:4304
 kmalloc_node_noprof include/linux/slab.h:928 [inline]
 __vmalloc_area_node mm/vmalloc.c:3647 [inline]
 __vmalloc_node_range_noprof+0x561/0x1380 mm/vmalloc.c:3846
 __vmalloc_node_noprof mm/vmalloc.c:3911 [inline]
 vzalloc_noprof+0x79/0x90 mm/vmalloc.c:3984
 alloc_counters+0xd7/0x770 net/ipv4/netfilter/ip_tables.c:799
 copy_entries_to_user net/ipv6/netfilter/ip6_tables.c:837 [inline]
 get_entries net/ipv6/netfilter/ip6_tables.c:1039 [inline]
 do_ip6t_get_ctl+0xecc/0x1820 net/ipv6/netfilter/ip6_tables.c:1677
 nf_getsockopt+0x299/0x2c0 net/netfilter/nf_sockopt.c:116
 ipv6_getsockopt+0x23e/0x360 net/ipv6/ipv6_sockglue.c:1493
 tcp_getsockopt+0x163/0x1c0 net/ipv4/tcp.c:4671
 do_sock_getsockopt+0x3c4/0x7e0 net/socket.c:2359
 __sys_getsockopt net/socket.c:2388 [inline]
 __do_sys_getsockopt net/socket.c:2395 [inline]
 __se_sys_getsockopt net/socket.c:2392 [inline]
 __x64_sys_getsockopt+0x2a1/0x370 net/socket.c:2392
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd88e58ea6a
Code: ff c3 66 0f 1f 44 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb b8 0f 1f 44 00 00 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 a8 ff ff ff f7
RSP: 002b:00007fff3bca6378 EFLAGS: 00000212 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 00007fff3bca6400 RCX: 00007fd88e58ea6a
RDX: 0000000000000041 RSI: 0000000000000029 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007fff3bca639c R09: 0079746972756365
R10: 00007fff3bca6400 R11: 0000000000000212 R12: 00007fd88e777c80
R13: 00007fff3bca639c R14: 0000000000000000 R15: 00007fd88e779e40
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/24 20:28 net 15a901361ec3 521b0ce3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in l2tp_eth_delete
* Struck through repros no longer work on HEAD.