INFO: task syz.1.434:7358 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc5-syzkaller-00159-g47c84997c686-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.434       state:D stack:28568 pid:7358  tgid:7356  ppid:5831   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x16f5/0x4d00
 bpf_prog_alloc_no_stats+0x4a/0x4e0
 bpf_prog_alloc_no_stats+0x4a/0x4e0
 bpf_prog_alloc+0x3c/0x1a0
 bpf_prog_create+0x9e/0x200
 ppp_get_filter+0x178/0x1c0
 ppp_ioctl+0xf1f/0x19a0
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f724e58e929
RSP: 002b:00007f724f3c4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f724e7b6080 RCX: 00007f724e58e929
RDX: 0000200000000080 RSI: 0000000040107447 RDI: 0000000000000004
RBP: 00007f724e610b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f724e7b6080 R15: 00007ffea86ed638
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13f160 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
4 locks held by kworker/u10:2/69:
 #0: ffff888136639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffffc9000173fbc0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88810aaf8768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xc4/0x460
 #3: ffff888136639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
4 locks held by udevd/5279:
2 locks held by dhcpcd/5576:
2 locks held by getty/5658:
 #0: ffff88810b1890a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by kworker/u8:2/5844:
 #0: ffff88810899a148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000344fbc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f51d808 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
2 locks held by syz.2.421/7309:
 #0: ffffffff8f51d808 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
 #1: ffffffff8e144c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
1 lock held by syz.0.430/7344:
 #0: ffffffff8f51d808 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
1 lock held by syz.1.434/7358:
 #0: ffffffff8f51d808 (rtnl_mutex){+.+.}-{4:4}, at: ppp_release+0x87/0x1f0
4 locks held by kworker/1:5/7362:
3 locks held by syz-executor/7364:
3 locks held by udevd/7365:
3 locks held by syz-executor/7366:
4 locks held by syz-executor/7367:
2 locks held by dhcpcd/7368:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Not tainted 6.16.0-rc5-syzkaller-00159-g47c84997c686-dirty #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+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xfee/0x1030
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5862 Comm: kworker/u8:4 Not tainted 6.16.0-rc5-syzkaller-00159-g47c84997c686-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: bat_events batadv_nc_worker
RIP: 0010:preempt_count_sub+0x37/0x170
Code: fc ff df 48 c7 c0 e0 92 ab 99 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 d1 00 00 00 83 3d 32 af 1a 18 00 75 25 65 8b 05 79 6c 0f 11 <89> c1 81 e1 ff ff ff 7f 39 cf 7f 2a 81 ff ff 00 00 00 0f 93 c1 84
RSP: 0018:ffffc900001dfe08 EFLAGS: 00000246
RAX: 0000000080000102 RBX: dffffc0000000000 RCX: ffffffff99ab9203
RDX: 0000000000000002 RSI: ffffffff8d998b14 RDI: 0000000000000001
RBP: ffffc900001dfeb0 R08: ffffffff8fa1f3f7 R09: 1ffffffff1f43e7e
R10: dffffc0000000000 R11: fffffbfff1f43e7f R12: dffffc0000000000
R13: ffff88803b184118 R14: ffffffff99cce8a8 R15: 1ffff9200003bfc4
FS:  0000000000000000(0000) GS:ffff8881a3c1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f012362eff8 CR3: 000000012ef2a000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 _raw_spin_unlock_irqrestore+0xad/0x110
 debug_object_activate+0x2e2/0x420
 call_rcu+0xaa/0x9c0
 skb_release_head_state+0x71/0x250
 consume_skb+0x60/0xf0
 arp_process+0xee8/0x17a0
 NF_HOOK+0x310/0x3a0
 __netif_receive_skb+0x164/0x380
 netif_receive_skb+0x1cb/0x790
 NF_HOOK+0xa0/0x390
 br_handle_frame_finish+0x14d1/0x19b0
 br_handle_frame+0xb89/0x14c0
 __netif_receive_skb_core+0x10e1/0x4180
 __netif_receive_skb+0x72/0x380
 process_backlog+0x60e/0x14f0
 __napi_poll+0xc7/0x480
 net_rx_action+0x707/0xe30
 handle_softirqs+0x286/0x870
 do_softirq+0xec/0x180
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x17d/0x1c0
 batadv_nc_purge_paths+0x318/0x3b0
 batadv_nc_worker+0x328/0x610
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
