------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 4349 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 4349 Comm: kworker/u4:7 Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: netns cleanup_net
RIP: 0010:refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Code: 09 01 48 c7 c7 a0 d2 be 8a e8 ad 30 45 fd 0f 0b eb e0 e8 f4 1d 79 fd c6 05 fa 72 e2 09 01 48 c7 c7 e0 d1 be 8a e8 91 30 45 fd <0f> 0b eb c4 e8 d8 1d 79 fd c6 05 df 72 e2 09 01 48 c7 c7 40 d2 be
RSP: 0018:ffffc900001e0828 EFLAGS: 00010246
RAX: de4177328e3edc00 RBX: 0000000000000002 RCX: ffff88802f373b80
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc900001e0990 R08: dffffc0000000000 R09: fffff5200003c095
R10: fffff5200003c095 R11: 1ffff9200003c094 R12: ffff888059423880
R13: dffffc0000000000 R14: 0000000000000002 R15: ffff88805827e848
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555593555c8 CR3: 000000002f754000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __refcount_add include/linux/refcount.h:-1 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 get_net include/net/net_namespace.h:257 [inline]
 tipc_aead_encrypt net/tipc/crypto.c:821 [inline]
 tipc_crypto_xmit+0x17a9/0x2300 net/tipc/crypto.c:1761
 tipc_bearer_xmit_skb+0x242/0x3f0 net/tipc/bearer.c:574
 tipc_disc_timeout+0x568/0x6b0 net/tipc/discover.c:338
 call_timer_fn+0x1a0/0x670 kernel/time/timer.c:1504
 expire_timers kernel/time/timer.c:1549 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1820
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc900045e6ec0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: de4177328e3edc00
RDX: dffffc0000000000 RSI: ffffffff8a6c1160 RDI: ffffffff8abf1360
RBP: ffffc900045e6fd8 R08: dffffc0000000000 R09: fffffbfff211704b
R10: fffffbfff211704b R11: 1ffffffff211704a R12: 0000000000000001
R13: 1ffff920008bcde4 R14: 0000000000000246 R15: dffffc0000000000
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 __mutex_lock_common kernel/locking/mutex.c:617 [inline]
 __mutex_lock+0x270/0xaf0 kernel/locking/mutex.c:747
 exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962
 dev_deactivate_many+0x635/0xcb0 net/sched/sch_generic.c:1370
 __dev_close_many+0x155/0x2a0 net/core/dev.c:1559
 dev_close_many+0x21f/0x400 net/core/dev.c:1597
 unregister_netdevice_many+0x471/0x1840 net/core/dev.c:10952
 unregister_netdevice_queue+0x31c/0x360 net/core/dev.c:10909
 unregister_netdevice include/linux/netdevice.h:3075 [inline]
 nsim_destroy+0x49/0x150 drivers/net/netdevsim/netdev.c:382
 __nsim_dev_port_del+0x155/0x1c0 drivers/net/netdevsim/dev.c:1433
 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1445 [inline]
 nsim_dev_reload_destroy+0x283/0x480 drivers/net/netdevsim/dev.c:1662
 nsim_dev_reload_down+0x86/0xb0 drivers/net/netdevsim/dev.c:968
 devlink_reload+0x1f1/0x660 net/devlink/leftover.c:4472
 devlink_pernet_pre_exit+0x116/0x270 net/devlink/leftover.c:12501
 ops_pre_exit_list net/core/net_namespace.c:162 [inline]
 cleanup_net+0x57b/0xb80 net/core/net_namespace.c:620
 process_one_work+0x898/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 9c 8f 84 24 80 00 	add    %bl,0x802484(%rdi,%rcx,4)
   7:	00 00                	add    %al,(%rax)
   9:	f6 84 24 81 00 00 00 	testb  $0x2,0x81(%rsp)
  10:	02
  11:	0f 85 f5 00 00 00    	jne    0x10c
  17:	41 f7 c6 00 02 00 00 	test   $0x200,%r14d
  1e:	74 01                	je     0x21
  20:	fb                   	sti
  21:	48 c7 44 24 60 0e 36 	movq   $0x45e0360e,0x60(%rsp)
  28:	e0 45
* 2a:	4b c7 44 3d 00 00 00 	movq   $0x0,0x0(%r13,%r15,1) <-- trapping instruction
  31:	00 00
  33:	66 43 c7 44 3d 09 00 	movw   $0x0,0x9(%r13,%r15,1)
  3a:	00
  3b:	43                   	rex.XB
  3c:	c6                   	.byte 0xc6
  3d:	44                   	rex.R
  3e:	3d                   	.byte 0x3d
  3f:	0b                   	.byte 0xb