------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 16326 at lib/refcount.c:25 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25
Modules linked in:
CPU: 1 UID: 0 PID: 16326 Comm: syz.3.3463 Not tainted 6.15.0-syzkaller-12293-g7fdaba912981 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25
Code: 00 00 e8 09 2d ff fc 5b 41 5e e9 d1 4a a7 06 cc e8 fb 2c ff fc c6 05 e3 ca c9 0a 01 90 48 c7 c7 c0 38 e2 8b e8 17 db c2 fc 90 <0f> 0b 90 90 eb d7 e8 db 2c ff fc c6 05 c4 ca c9 0a 01 90 48 c7 c7
RSP: 0018:ffffc90000a18828 EFLAGS: 00010246
RAX: 465de8005e4fc900 RBX: 0000000000000002 RCX: ffff888075511e00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc90000a189b0 R08: ffff8880b8724293 R09: 1ffff110170e4852
R10: dffffc0000000000 R11: ffffed10170e4853 R12: ffff888031d4a080
R13: dffffc0000000000 R14: ffff888031d4a1ec R15: ffff888032391800
FS:  0000000000000000(0000) GS:ffff888125d55000(0063) knlGS:00000000f503db40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000080150018 CR3: 0000000066a6e000 CR4: 00000000003526f0
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:366 [inline]
 refcount_inc include/linux/refcount.h:383 [inline]
 get_net include/net/net_namespace.h:268 [inline]
 tipc_aead_encrypt net/tipc/crypto.c:821 [inline]
 tipc_crypto_xmit+0x1820/0x22c0 net/tipc/crypto.c:1761
 tipc_bearer_xmit_skb+0x245/0x400 net/tipc/bearer.c:572
 tipc_disc_timeout+0x580/0x6d0 net/tipc/discover.c:338
 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1747
 expire_timers kernel/time/timer.c:1798 [inline]
 __run_timers kernel/time/timer.c:2372 [inline]
 __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
 run_timer_base kernel/time/timer.c:2393 [inline]
 run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
 handle_softirqs+0x286/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_is_held_type+0x137/0x190 kernel/locking/lockdep.c:5948
Code: 01 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 05 09 03 37 07 <48> 3b 44 24 08 75 43 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc90013ab6eb8 EFLAGS: 00000206
RAX: 465de8005e4fc900 RBX: 0000000000000000 RCX: 465de8005e4fc900
RDX: 0000000000000000 RSI: ffffffff8db69626 RDI: ffffffff8be28340
RBP: 00000000ffffffff R08: ffffc90013ab717f R09: 0000000000000000
R10: ffffc90013ab7168 R11: ffffffff82020730 R12: 0000000000000246
R13: ffff888075511e00 R14: ffffffff8e13f0c0 R15: 0000000000000001
 lock_is_held include/linux/lockdep.h:249 [inline]
 __might_resched+0xa6/0x610 kernel/sched/core.c:8762
 down_write+0x76/0x1f0 kernel/locking/rwsem.c:1576
 inode_lock include/linux/fs.h:867 [inline]
 shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3453
 __kernel_write_iter+0x390/0x860 fs/read_write.c:619
 dump_emit_page fs/coredump.c:1112 [inline]
 dump_user_range+0x873/0xc70 fs/coredump.c:1186
 elf_core_dump+0x3866/0x4090 fs/binfmt_elf.c:2075
 do_coredump+0x2806/0x3440 fs/coredump.c:950
 get_signal+0x1109/0x1340 kernel/signal.c:3019
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 __do_fast_syscall_32+0x1f4/0x2b0 arch/x86/entry/syscall_32.c:309
 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf706e539
Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f503d61c EFLAGS: 00000206 ORIG_RAX: 00000000000000f0
RAX: 00000000000000f0 RBX: 00000000f740501c RCX: 0000000000000081
RDX: 00000000000f4240 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	01 75 44             	add    %esi,0x44(%rbp)
   3:	48 c7 04 24 00 00 00 	movq   $0x0,(%rsp)
   a:	00
   b:	9c                   	pushf
   c:	8f 04 24             	pop    (%rsp)
   f:	f7 04 24 00 02 00 00 	testl  $0x200,(%rsp)
  16:	75 4c                	jne    0x64
  18:	41 f7 c4 00 02 00 00 	test   $0x200,%r12d
  1f:	74 01                	je     0x22
  21:	fb                   	sti
  22:	65 48 8b 05 09 03 37 	mov    %gs:0x7370309(%rip),%rax        # 0x7370333
  29:	07
* 2a:	48 3b 44 24 08       	cmp    0x8(%rsp),%rax <-- trapping instruction
  2f:	75 43                	jne    0x74
  31:	89 d8                	mov    %ebx,%eax
  33:	48 83 c4 10          	add    $0x10,%rsp
  37:	5b                   	pop    %rbx
  38:	41 5c                	pop    %r12
  3a:	41 5d                	pop    %r13
  3c:	41 5e                	pop    %r14
  3e:	41 5f                	pop    %r15