syzbot


INFO: task hung in load_settype

Status: auto-obsoleted due to no activity on 2026/04/14 20:46
Subsystems: netfilter
[Documentation on labels]
First crash: 92d, last: 92d
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
08891d82-8bb3-477a-b0b2-8f7547beec35 repro INFO: task hung in load_settype 2026/03/08 04:07 2026/03/08 04:07 2026/03/08 04:19 31e9c887f7dc24e04b3ca70d0d54fc34141844b0

Sample crash report:
INFO: task syz.4.3356:18446 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.3356      state:D stack:23936 pid:18446 tgid:18444 ppid:17322  task_flags:0x400140 flags:0x10080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
 load_settype+0x5f/0xe0 net/netfilter/ipset/ip_set_core.c:-1
 __find_set_type_get net/netfilter/ipset/ip_set_core.c:134 [inline]
 ip_set_create+0x486/0x19c0 net/netfilter/ipset/ip_set_core.c:1095
 nfnetlink_rcv_msg+0xb4d/0x1130 net/netfilter/nfnetlink.c:302
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
 nfnetlink_rcv+0x282/0x2590 net/netfilter/nfnetlink.c:669
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x505/0x820 net/socket.c:2592
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646
 __sys_sendmsg+0x164/0x220 net/socket.c:2678
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x1dc/0x570 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf703d539
RSP: 002b:00000000f540c55c EFLAGS: 00000206 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 0000000080000040
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_exp_gp_kthr/18:
1 lock held by khungtaskd/31:
 #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by dhcpcd/5495:
 #0: ffff8880b863a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647
2 locks held by getty/5588:
 #0: ffff888034e9d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211
2 locks held by kworker/0:6/5906:
 #0: ffff88813ff15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff88813ff15948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc9000493fbc0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc9000493fbc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
3 locks held by kworker/u8:15/5969:
 #0: ffff88813ff29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff88813ff29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
 #1: ffffc90004d7fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc90004d7fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
 #2: ffffffff8f311e88 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
3 locks held by syz.0.2050/13142:
1 lock held by syz.4.3356/18446:
 #0: ffffffff99de32f8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: load_settype+0x5f/0xe0 net/netfilter/ipset/ip_set_core.c:-1
1 lock held by syz.3.3430/18721:
 #0: ffffffff99de32f8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline]
 #0: ffffffff99de32f8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0x9dc/0x1130 net/netfilter/nfnetlink.c:295
1 lock held by syz.6.3516/19031:
 #0: ffffffff99de32f8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline]
 #0: ffffffff99de32f8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0x9dc/0x1130 net/netfilter/nfnetlink.c:295
1 lock held by syz.5.3588/19273:
 #0: ffffffff99de32f8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline]
 #0: ffffffff99de32f8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0x9dc/0x1130 net/netfilter/nfnetlink.c:295
1 lock held by syz.9.3642/19474:
 #0: ffffffff99de32f8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline]
 #0: ffffffff99de32f8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0x9dc/0x1130 net/netfilter/nfnetlink.c:295
1 lock held by syz.9.3642/19476:
 #0: ffffffff99de32f8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline]
 #0: ffffffff99de32f8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0x9dc/0x1130 net/netfilter/nfnetlink.c:295
1 lock held by syz.9.3642/19477:
 #0: ffffffff99de32f8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline]
 #0: ffffffff99de32f8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0x9dc/0x1130 net/netfilter/nfnetlink.c:295
5 locks held by syz-executor/19565:
 #0: ffff8880a6e58ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
 #0: ffff8880a6e58ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5b0 net/bluetooth/hci_core.c:2715
 #1: ffff8880a6e580c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x1100 net/bluetooth/hci_sync.c:5314
 #2: ffffffff8f483a48 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2143 [inline]
 #2: ffffffff8f483a48 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2637
 #3: ffff8880b09b9b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 net/bluetooth/l2cap_core.c:1763
 #4: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
 #4: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x36e/0x6e0 kernel/rcu/tree_exp.h:956
1 lock held by syz-executor/19578:
 #0: ffffffff8f311e88 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
 #0: ffffffff8f311e88 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
1 lock held by syz.7.3748/20041:
 #0: ffffffff99de32f8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline]
 #0: ffffffff99de32f8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0x9dc/0x1130 net/netfilter/nfnetlink.c:295
1 lock held by syz-executor/20243:
 #0: ffffffff8f311e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8f311e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #0: ffffffff8f311e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
1 lock held by syz.0.3795/20264:
 #0: ffffffff8df474c0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3816
2 locks held by syz.0.3795/20282:
 #0: ffffffff8f379af0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffffffff8f379908 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff8f379908 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff8f379908 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209
3 locks held by syz.8.3798/20274:
 #0: ffffffff8f379af0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffffffff8f379908 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff8f379908 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff8f379908 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209
 #2: ffffffff8f311e88 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_register_hw+0x36fb/0x4110 net/mac80211/main.c:1644
2 locks held by syz.2.3799/20275:
 #0: ffffffff8f311e88 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
 #0: ffffffff8f311e88 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
 #1: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #1: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2b1/0x6e0 kernel/rcu/tree_exp.h:956

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xf95/0xfe0 kernel/hung_task.c:515
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 53 91 0e 00 f3 0f 1e fa fb f4 <e9> 08 e3 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 000002c6
RAX: 0000000000e6a6f7 RBX: ffffffff8197149e RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d792d31 RDI: ffffffff8bc086e0
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8f822470
R13: 1ffff110038d6b70 R14: 0000000000000001 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000080202018 CR3: 000000000dd3a000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:191 [inline]
 do_idle+0x1be/0x4d0 kernel/sched/idle.c:332
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x147
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/14 20:35 upstream c537e12daeec d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in load_settype
* Struck through repros no longer work on HEAD.