INFO: task hung in ipmr_net_exit_batch (5)

Status: auto-obsoleted due to no activity on 2026/07/09 06:50
Subsystems: net
Labels: prio:normal
[Documentation on labels]
First crash: 250d, last: 126d
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
5fa03f50 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ INFO: task hung in ipmr_net_exit_batch (5) 2026/05/15 21:44 2026/05/15 21:44 2026/05/15 22:44 efdaf0f9
fee4f00f repro INFO: task hung in ipmr_net_exit_batch (5) 2026/03/07 16:59 2026/03/07 16:59 2026/03/07 17:10 31e9c887
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in ipmr_net_exit_batch net 1 1 1323d 1323d 0/29 auto-obsoleted due to no activity on 2023/04/06 09:54
linux-6.1 INFO: task hung in ipmr_net_exit_batch 1 2 789d 799d 0/3 auto-obsoleted due to no activity on 2024/09/23 16:16
linux-6.6 INFO: task hung in ipmr_net_exit_batch 1 1 38d 38d 0/2 upstream: reported on 2026/07/07 06:31
upstream INFO: task hung in ipmr_net_exit_batch (4) net 1 1 541d 541d 0/29 auto-obsoleted due to no activity on 2025/05/19 15:32
upstream INFO: task hung in ipmr_net_exit_batch (2) net 1 6 787d 815d 0/29 auto-obsoleted due to no activity on 2024/09/16 02:09
upstream INFO: task hung in ipmr_net_exit_batch (3) net 1 syz 6 658d 661d 0/29 closed as invalid on 2024/11/27 19:42

Sample crash report:
INFO: task kworker/u8:2:34 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:2    state:D stack:21248 pid:34    tgid:34    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7008
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
 ipmr_net_exit_batch+0x20/0x90 net/ipv4/ipmr.c:3276
 ops_exit_list net/core/net_namespace.c:205 [inline]
 ops_undo_list+0x52b/0x940 net/core/net_namespace.c:252
 cleanup_net+0x56b/0x800 net/core/net_namespace.c:704
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
1 lock held by kthreadd/2:
1 lock held by kworker/0:0/9:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x2e/0x3a0 kernel/workqueue.c:2691
3 locks held by kworker/0:1/10:
6 locks held by kworker/u8:0/12:
3 locks held by kworker/u8:1/13:
1 lock held by kworker/R-mm_pe/14:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x2e/0x3a0 kernel/workqueue.c:2691
2 locks held by kworker/1:1/29:
1 lock held by khungtaskd/31:
 #0: ffffffff8e75e5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8e75e5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8e75e5a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by kworker/R-write/33:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x2e/0x3a0 kernel/workqueue.c:2691
4 locks held by kworker/u8:2/34:
 #0: ffff88801bad6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #0: ffff88801bad6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
 #1: ffffc90000aa7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
 #1: ffffc90000aa7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
 #2: ffffffff8fbc22f0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675
 #3: ffffffff8fbd0a88 (rtnl_mutex){+.+.}-{4:4}, at: ipmr_net_exit_batch+0x20/0x90 net/ipv4/ipmr.c:3276
3 locks held by kworker/u8:4/70:
5 locks held by kworker/u8:5/125:
3 locks held by kworker/u8:6/136:
3 locks held by kworker/u8:7/148:
3 locks held by kworker/1:2/792:
4 locks held by kworker/0:2/976:
5 locks held by kworker/R-mld/3177:
3 locks held by kworker/R-ipv6_/3178:
 #0: ffff888031cb9948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #0: ffff888031cb9948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
 #1: ffffc9000cbffc00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
 #1: ffffc9000cbffc00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
 #2: ffffffff8fbd0a88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8fbd0a88 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4738
2 locks held by kworker/R-bat_e/3403:
1 lock held by klogd/5176:
3 locks held by udevd/5187:
1 lock held by dhcpcd/5481:
1 lock held by dhcpcd/5482:
2 locks held by getty/5575:
 #0: ffff888036d400a0 (&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+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5804:
4 locks held by syz-executor/5819:
4 locks held by syz-executor/5822:
4 locks held by kworker/0:3/5826:
 #0: ffff88807e615548 ((wq_completion)wg-kex-wg1#8){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #0: ffff88807e615548 ((wq_completion)wg-kex-wg1#8){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
 #1: ffffc900037f7c40 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
 #1: ffffc900037f7c40 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
 #2: ffff888054e35388 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x1a1/0x9a0 drivers/net/wireguard/noise.c:598
 #3: ffff888020331708 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x630/0x9a0 drivers/net/wireguard/noise.c:643
4 locks held by kworker/1:3/5828:
 #0: ffff888054b3f948 ((wq_completion)wg-kex-wg2#10){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #0: ffff888054b3f948 ((wq_completion)wg-kex-wg2#10){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
 #1: ffffc900038d7c40 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
 #1: ffffc900038d7c40 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
 #2: ffff888079089388 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x1a1/0x9a0 drivers/net/wireguard/noise.c:598
 #3: ffff888052956648 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x58b/0x9a0 drivers/net/wireguard/noise.c:632
5 locks held by syz-executor/5835:
1 lock held by kworker/R-wg-cr/5854:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2749 [inline]
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xc4d/0x1130 kernel/workqueue.c:3611
1 lock held by kworker/R-wg-cr/5855:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2749 [inline]
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xc4d/0x1130 kernel/workqueue.c:3611
1 lock held by kworker/R-wg-cr/5857:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2749 [inline]
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xc4d/0x1130 kernel/workqueue.c:3611
1 lock held by kworker/R-wg-cr/5865:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2749 [inline]
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xc4d/0x1130 kernel/workqueue.c:3611
1 lock held by kworker/R-wg-cr/5866:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2749 [inline]
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xc4d/0x1130 kernel/workqueue.c:3611
1 lock held by kworker/R-wg-cr/5867:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2749 [inline]
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xc4d/0x1130 kernel/workqueue.c:3611
1 lock held by kworker/R-wg-cr/5870:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x2e/0x3a0 kernel/workqueue.c:2691
1 lock held by kworker/R-wg-cr/5871:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2749 [inline]
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xc4d/0x1130 kernel/workqueue.c:3611
1 lock held by kworker/R-wg-cr/5873:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x2e/0x3a0 kernel/workqueue.c:2691
1 lock held by kworker/R-wg-cr/5875:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2749 [inline]
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xc4d/0x1130 kernel/workqueue.c:3611
1 lock held by kworker/R-wg-cr/5879:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2749 [inline]
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xc4d/0x1130 kernel/workqueue.c:3611
1 lock held by kworker/R-wg-cr/5880:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2749 [inline]
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xc4d/0x1130 kernel/workqueue.c:3611
1 lock held by kworker/R-wg-cr/5881:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2749 [inline]
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xc4d/0x1130 kernel/workqueue.c:3611
1 lock held by kworker/R-wg-cr/5882:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2749 [inline]
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xc4d/0x1130 kernel/workqueue.c:3611
1 lock held by kworker/R-wg-cr/5883:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2749 [inline]
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xc4d/0x1130 kernel/workqueue.c:3611
1 lock held by kworker/R-wg-cr/5884:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2749 [inline]
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0xc4d/0x1130 kernel/workqueue.c:3611
4 locks held by kworker/1:4/5885:
1 lock held by kworker/R-wg-cr/5886:
3 locks held by kworker/0:4/5911:
3 locks held by kworker/0:5/5918:
3 locks held by kworker/0:8/6026:
1 lock held by udevd/6027:
4 locks held by udevd/6031:
1 lock held by udevd/6167:
 #0: ffff888035043d00 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline]
 #0: ffff888035043d00 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: open_last_lookups fs/namei.c:4588 [inline]
 #0: ffff888035043d00 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: path_openat+0xb3d/0x3860 fs/namei.c:4833
2 locks held by udevd/7763:
3 locks held by kworker/u8:3/17620:
4 locks held by kworker/u8:8/17622:
3 locks held by kworker/u8:9/17624:
3 locks held by kworker/u8:10/17626:
3 locks held by kworker/u8:11/17628:
3 locks held by kworker/u8:12/17630:
4 locks held by kworker/u8:13/17632:
3 locks held by kworker/u8:14/17634:
4 locks held by kworker/u8:15/17635:
 #0: ffff88802a748148 ((wq_completion)wg-kex-wg1#5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #0: ffff88802a748148 ((wq_completion)wg-kex-wg1#5){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
 #1: ffffc9000fc8fc40 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
 #1: ffffc9000fc8fc40 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
 #2: ffff888033629388 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x12f/0x830 drivers/net/wireguard/noise.c:529
 #3: ffff888020336648 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x140/0x830 drivers/net/wireguard/noise.c:530
6 locks held by syz.3.5108/17725:
3 locks held by syz.0.5112/17736:
4 locks held by syz.1.5113/17735:
1 lock held by kworker/u8:16/17743:
 #0: ffffffff8e5fce68 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x2e/0x3a0 kernel/workqueue.c:2691

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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:161 [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+0xfd9/0x1030 kernel/hung_task.c:515
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 125 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker
RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:879 [inline]
RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
RIP: 0010:unwind_next_frame+0x1a68/0x23c0 arch/x86/kernel/unwind_orc.c:695
Code: 8b 64 24 20 41 0f b6 04 2c 84 c0 0f 85 35 02 00 00 41 c7 06 00 00 00 00 31 db e8 f3 33 39 0a 85 c0 74 3a e8 4a 29 34 00 84 c0 <75> 31 e8 e1 33 39 0a 85 c0 74 28 80 3d 3f 08 85 0e 00 75 1f c6 05
RSP: 0018:ffffc900000069d8 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff912d2101 RCX: 0000000080000102
RDX: ffffc90000006a01 RSI: ffffffff8c27d560 RDI: ffffffff8c27d520
RBP: dffffc0000000000 R08: ffffc90000007d30 R09: ffffc90000006af8
R10: dffffc0000000000 R11: fffff52000000d61 R12: ffffc90000007d40
R13: ffffc90000000000 R14: ffffc90000006aa8 R15: ffffffff81768a55
FS:  0000000000000000(0000) GS:ffff888125454000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3608fffeac CR3: 00000000333e3000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kmem_cache_free+0x187/0x630 mm/slub.c:6295
 skb_ext_reset include/linux/skbuff.h:5090 [inline]
 skb_release_head_state+0x270/0x360 net/core/skbuff.c:1192
 skb_release_all net/core/skbuff.c:1198 [inline]
 __kfree_skb+0x24/0x210 net/core/skbuff.c:1214
 kfree_skb_reason include/linux/skbuff.h:1322 [inline]
 kfree_skb include/linux/skbuff.h:1331 [inline]
 ip6_mc_input+0x8de/0xbd0 net/ipv6/ip6_input.c:593
 ip_sabotage_in+0x1e1/0x270 net/bridge/br_netfilter_hooks.c:990
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
 nf_hook include/linux/netfilter.h:273 [inline]
 NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316
 __netif_receive_skb_one_core net/core/dev.c:6181 [inline]
 __netif_receive_skb net/core/dev.c:6294 [inline]
 netif_receive_skb_internal net/core/dev.c:6380 [inline]
 netif_receive_skb+0x278/0xc50 net/core/dev.c:6439
 NF_HOOK+0xa4/0x3a0 include/linux/netfilter.h:318
 br_handle_frame_finish+0x14e2/0x1bb0 net/bridge/br_input.c:-1
 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1
 br_nf_pre_routing_finish_ipv6+0xa3a/0xd70 net/bridge/br_netfilter_ipv6.c:-1
 NF_HOOK include/linux/netfilter.h:318 [inline]
 br_nf_pre_routing_ipv6+0x374/0x6f0 net/bridge/br_netfilter_ipv6.c:184
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
 br_handle_frame+0x1277/0x1510 net/bridge/br_input.c:442
 __netif_receive_skb_core+0x98f/0x31a0 net/core/dev.c:6068
 __netif_receive_skb_one_core net/core/dev.c:6179 [inline]
 __netif_receive_skb net/core/dev.c:6294 [inline]
 process_backlog+0x76d/0x1950 net/core/dev.c:6645
 __napi_poll+0xae/0x340 net/core/dev.c:7709
 napi_poll net/core/dev.c:7772 [inline]
 net_rx_action+0x627/0xf70 net/core/dev.c:7929
 handle_softirqs+0x22a/0x870 kernel/softirq.c:622
 do_softirq+0x76/0xd0 kernel/softirq.c:523
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:36 [inline]
 wg_packet_handshake_send_worker+0x1b2/0x350 drivers/net/wireguard/send.c:51
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
net_ratelimit: 13186 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:8e:b9:85:91:f2:11, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:8e:b9:85:91:f2:11, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:8e:b9:85:91:f2:11, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:8e:b9:85:91:f2:11, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:8e:b9:85:91:f2:11, vlan:0)
net_ratelimit: 13625 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:8e:b9:85:91:f2:11, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:8e:b9:85:91:f2:11, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:8e:b9:85:91:f2:11, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:8e:b9:85:91:f2:11, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
net_ratelimit: 13669 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:8e:b9:85:91:f2:11, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:8e:b9:85:91:f2:11, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:8e:b9:85:91:f2:11, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:8e:b9:85:91:f2:11, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/10 06:41 upstream 9a9c8ce300cd 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in ipmr_net_exit_batch
2026/01/11 20:09 upstream 755bc1335e3b d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in ipmr_net_exit_batch
2025/12/07 04:24 net 0373d5c387f2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in ipmr_net_exit_batch
2025/12/27 14:54 net-next 7b8e9264f55a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in ipmr_net_exit_batch
* Struck through repros no longer work on HEAD.