syzbot

INFO: task syz.2.559:8162 blocked for more than 155 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.559       state:D stack:25368 pid:8162  tgid:8152  ppid:5827   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x10e9/0x6820 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7282
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7339
 rwsem_down_write_slowpath+0x4c2/0x12c0 kernel/locking/rwsem.c:1215
 __down_write_common kernel/locking/rwsem.c:1347 [inline]
 __down_write kernel/locking/rwsem.c:1356 [inline]
 down_write+0x1c7/0x1f0 kernel/locking/rwsem.c:1626
 rdma_dev_exit_net+0x177/0x590 drivers/infiniband/core/device.c:1132
 ops_exit_list net/core/net_namespace.c:199 [inline]
 ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:252
 setup_net+0x1fa/0x3a0 net/core/net_namespace.c:462
 copy_net_ns+0x46f/0x7c0 net/core/net_namespace.c:579
 create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:132
 unshare_nsproxy_namespaces+0xf2/0x220 kernel/nsproxy.c:234
 ksys_unshare+0x438/0xab0 kernel/fork.c:3245
 __do_sys_unshare kernel/fork.c:3319 [inline]
 __se_sys_unshare kernel/fork.c:3317 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3317
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4da2d9c819
RSP: 002b:00007f4da3c01028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f4da3016180 RCX: 00007f4da2d9c819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000062040200
RBP: 00007f4da2e32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4da3016218 R14: 00007f4da3016180 R15: 00007ffd5af4d468
 </TASK>
INFO: task syz-executor:8253 blocked for more than 155 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:26968 pid:8253  tgid:8253  ppid:8244   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x10e9/0x6820 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7282
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7339
 rwsem_down_read_slowpath+0x5af/0xb40 kernel/locking/rwsem.c:1114
 __down_read_common kernel/locking/rwsem.c:1291 [inline]
 __down_read kernel/locking/rwsem.c:1304 [inline]
 down_read+0xed/0x450 kernel/locking/rwsem.c:1570
 rdma_dev_init_net+0x2ff/0x590 drivers/infiniband/core/device.c:1193
 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
 setup_net+0x118/0x3a0 net/core/net_namespace.c:446
 copy_net_ns+0x46f/0x7c0 net/core/net_namespace.c:579
 create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:132
 unshare_nsproxy_namespaces+0xf2/0x220 kernel/nsproxy.c:234
 ksys_unshare+0x438/0xab0 kernel/fork.c:3245
 __do_sys_unshare kernel/fork.c:3319 [inline]
 __se_sys_unshare kernel/fork.c:3317 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3317
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f117fb9dae7
RSP: 002b:00007fffdf031038 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f117fe15f40 RCX: 00007f117fb9dae7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f117fe167b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 00007fffdf031278 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
1 lock held by kthreadd/2:
4 locks held by kworker/u8:0/12:
3 locks held by kworker/u8:1/13:
1 lock held by khungtaskd/31:
 #0: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:2/36:
4 locks held by kworker/u8:3/47:
3 locks held by kworker/u8:4/65:
2 locks held by kswapd0/84:
3 locks held by kworker/u8:5/133:
3 locks held by kworker/u8:6/142:
3 locks held by kworker/u8:7/160:
3 locks held by kworker/u8:8/1118:
3 locks held by kworker/u8:9/1120:
3 locks held by kworker/u8:10/1344:
6 locks held by kworker/R-bat_e/3424:
5 locks held by kworker/u8:11/3545:
 #0: ffff88801c6d8940 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
 #1: ffffc9000ef3fd08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
 #2: ffffffff90616e48 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673
 #3: ffff88805209d550 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x151/0x3f0 drivers/net/wireguard/device.c:249
 #4: ffffffff8e7f0e78 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828
2 locks held by jbd2/sda1-8/5159:
2 locks held by udevd/5198:
2 locks held by crond/5567:
2 locks held by getty/5587:
 #0: ffff8880392060a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/5811:
1 lock held by syz-executor/5824:
 #0: ffffffff8e7f0fa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
5 locks held by kworker/u9:2/5825:
 #0: ffff8880530d9940 ((wq_completion)hci6){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
 #1: ffffc90002fd7d08 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
 #2: ffff8880272acea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x18a/0x470 net/bluetooth/hci_sync.c:331
 #3: ffff8880272ac0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x141/0xb20 net/bluetooth/hci_sync.c:5744
 #4: ffffffff908c6e40 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline]
 #4: ffffffff908c6e40 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x119/0x360 net/bluetooth/hci_conn.c:1342
7 locks held by kworker/u9:4/5831:
 #0: ffff88802c657140 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
 #1: ffffc90004597d08 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
 #2: ffff888045114ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x18a/0x470 net/bluetooth/hci_sync.c:331
 #3: ffff8880451140b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x141/0xb20 net/bluetooth/hci_sync.c:5744
 #4: ffffffff908c6e40 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2136 [inline]
 #4: ffffffff908c6e40 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x119/0x360 net/bluetooth/hci_conn.c:1342
 #5: ffff888074cbbaf8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x95/0x710 net/bluetooth/l2cap_core.c:1777
 #6: ffffffff8e7f0fa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
2 locks held by syz-executor/5835:
2 locks held by kworker/1:3/5878:
4 locks held by kworker/1:6/5951:
3 locks held by kworker/u8:12/7773:
3 locks held by kworker/u8:13/8009:
2 locks held by syz.2.559/8162:
 #0: ffffffff90616e48 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
 #1: ffffffff90246488 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_exit_net+0x177/0x590 drivers/infiniband/core/device.c:1132
5 locks held by syz-executor/8227:
3 locks held by syz-executor/8253:
 #0: ffffffff90616e48 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
 #1: ffffffff90246708 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x28c/0x590 drivers/infiniband/core/device.c:1188
 #2: ffffffff90246488 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x2ff/0x590 drivers/infiniband/core/device.c:1193
4 locks held by dhcpcd-run-hook/8296:
3 locks held by kworker/u8:14/8297:

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

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 04/18/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xcb1/0x1030 kernel/hung_task.c:561
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 3424 Comm: kworker/R-bat_e Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: bat_events batadv_tt_purge
RIP: 0010:unwind_done arch/x86/include/asm/unwind.h:50 [inline]
RIP: 0010:__unwind_start+0x3dc/0x7f0 arch/x86/kernel/unwind_orc.c:784
Code: 00 00 00 00 00 fc ff df 49 c1 ed 03 49 89 c4 49 01 ed 49 01 ec eb 2a 4c 89 f7 e8 8f db ff ff 4c 89 f0 48 c1 e8 03 0f b6 04 28 <84> c0 74 08 3c 03 0f 8e c1 02 00 00 41 8b 06 85 c0 0f 84 e5 fe ff
RSP: 0018:ffffc90000a07d08 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffffc90000a07de8 RCX: ffffc90000a07c5c
RDX: 0000000000000000 RSI: ffffffff8df34f8f RDI: ffff888034b2cec4
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 000000000000b8d1 R12: fffff52000140fad
R13: fffff52000140fac R14: ffffc90000a07d58 R15: ffffc90000a07d60
FS:  0000000000000000(0000) GS:ffff8881243db000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558b4f54e8 CR3: 0000000038217000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0x73/0xf0 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4905
 dst_alloc+0x99/0x1a0 net/core/dst.c:90
 rt_dst_alloc+0x35/0x3a0 net/ipv4/route.c:1651
 __mkroute_output net/ipv4/route.c:2655 [inline]
 ip_route_output_key_hash_rcu+0x87a/0x2870 net/ipv4/route.c:2875
 ip_route_output_key_hash+0x118/0x2b0 net/ipv4/route.c:2705
 __ip_route_output_key include/net/route.h:169 [inline]
 ip_route_output_flow+0x27/0x150 net/ipv4/route.c:2932
 ip_route_output_key include/net/route.h:179 [inline]
 ip_route_me_harder+0x562/0x1260 net/ipv4/netfilter.c:54
 synproxy_send_tcp.isra.0+0x341/0x680 net/netfilter/nf_synproxy_core.c:432
 synproxy_send_client_synack+0x6ea/0x970 net/netfilter/nf_synproxy_core.c:485
 nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:60 [inline]
 nft_synproxy_do_eval+0xa6a/0xd50 net/netfilter/nft_synproxy.c:142
 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
 nft_do_chain+0x2e5/0x1950 net/netfilter/nf_tables_core.c:285
 nft_do_chain_inet+0xf3/0x400 net/netfilter/nft_chain_filter.c:162
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619
 nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:273
 NF_HOOK include/linux/netfilter.h:316 [inline]
 ip_local_deliver+0x163/0x1f0 net/ipv4/ip_input.c:262
 dst_input include/net/dst.h:480 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:492 [inline]
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK include/linux/netfilter.h:312 [inline]
 ip_rcv+0x33a/0x3c0 net/ipv4/ip_input.c:612
 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6209
 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6322
 process_backlog+0x37a/0x1580 net/core/dev.c:6673
 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7737
 napi_poll net/core/dev.c:7800 [inline]
 net_rx_action+0xa40/0xf20 net/core/dev.c:7957
 handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622
 do_softirq kernel/softirq.c:523 [inline]
 do_softirq+0xac/0xe0 kernel/softirq.c:510
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 batadv_tt_global_purge net/batman-adv/translation-table.c:2255 [inline]
 batadv_tt_purge+0x25d/0xbd0 net/batman-adv/translation-table.c:3515
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
 process_scheduled_works kernel/workqueue.c:3385 [inline]
 rescuer_thread+0x905/0x14a0 kernel/workqueue.c:3609
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>