------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 4724 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 4724 Comm: kworker/u4:17 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Code: 09 01 48 c7 c7 40 6b 59 8a e8 dd 27 bb 05 0f 0b eb e0 e8 04 42 9c fd c6 05 ae 8f 79 09 01 48 c7 c7 80 6a 59 8a e8 c1 27 bb 05 <0f> 0b eb c4 e8 e8 41 9c fd c6 05 93 8f 79 09 01 48 c7 c7 e0 6a 59
RSP: 0018:ffffc90000007848 EFLAGS: 00010246
RAX: 67302a3c45c83300 RBX: 0000000000000002 RCX: ffff88801ed69dc0
RDX: 0000000000000100 RSI: 0000000000000100 RDI: 0000000000000000
RBP: ffffc900000079b0 R08: dffffc0000000000 R09: fffff52000000e6d
R10: fffff52000000e6d R11: 1ffff92000000e6c R12: ffff88807acab500
R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2914e7 CR3: 0000000051a1e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000001000 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:252 [inline]
 tipc_aead_encrypt net/tipc/crypto.c:832 [inline]
 tipc_crypto_xmit+0x1949/0x2560 net/tipc/crypto.c:1772
 tipc_bearer_xmit_skb+0x228/0x3c0 net/tipc/bearer.c:574
 tipc_disc_timeout+0x568/0x6b0 net/tipc/discover.c:338
 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:rcu_lock_release+0x0/0x20 include/linux/rcupdate.h:316
Code: 96 81 00 f8 48 c7 c7 a0 bf 11 8c 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 68 85 40 77 89 e8 d6 a4 e4 f7 48 83 c4 08 c3 90 <e8> 6b 81 00 f8 e8 66 81 00 f8 48 c7 c7 a0 bf 11 8c 48 c7 c6 b5 40
RSP: 0018:ffffc900034bfbd8 EFLAGS: 00000287
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff88801ed69dc0
RDX: 0000000000000000 RSI: ffffffff8a59a720 RDI: ffff88801ed69dc0
RBP: ffff88801fefb140 R08: dffffc0000000000 R09: fffffbfff1ff3619
R10: fffffbfff1ff3619 R11: 1ffffffff1ff3618 R12: 0000000000000297
R13: fffffffffffffe38 R14: ffff888029528c80 R15: ffff88801fefb150
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline]
 batadv_nc_worker+0x25b/0x5c0 net/batman-adv/network-coding.c:723
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
----------------
Code disassembly (best guess):
   0:	96                   	xchg   %eax,%esi
   1:	81 00 f8 48 c7 c7    	addl   $0xc7c748f8,(%rax)
   7:	a0 bf 11 8c 31 f6 31 	movabs 0xb9d231f6318c11bf,%al
   e:	d2 b9
  10:	02 00                	add    (%rax),%al
  12:	00 00                	add    %al,(%rax)
  14:	45 31 c0             	xor    %r8d,%r8d
  17:	45 31 c9             	xor    %r9d,%r9d
  1a:	68 85 40 77 89       	push   $0xffffffff89774085
  1f:	e8 d6 a4 e4 f7       	call   0xf7e4a4fa
  24:	48 83 c4 08          	add    $0x8,%rsp
  28:	c3                   	ret
  29:	90                   	nop
* 2a:	e8 6b 81 00 f8       	call   0xf800819a <-- trapping instruction
  2f:	e8 66 81 00 f8       	call   0xf800819a
  34:	48 c7 c7 a0 bf 11 8c 	mov    $0xffffffff8c11bfa0,%rdi
  3b:	48                   	rex.W
  3c:	c7                   	.byte 0xc7
  3d:	c6                   	(bad)
  3e:	b5 40                	mov    $0x40,%ch