------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 20555 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 20555 Comm: syz-executor Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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: 0000:ffffc900001e0688 EFLAGS: 00010246
RAX: 3fac0f1e8e266c00 RBX: 0000000000000002 RCX: ffff88802efb8000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc900001e07e8 R08: dffffc0000000000 R09: fffff5200003c061
R10: fffff5200003c061 R11: 1ffff9200003c060 R12: ffff8880765a8000
R13: dffffc0000000000 R14: 0000000000000002 R15: ffff88807e583448
FS:  000055558b68d500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe602b565c0 CR3: 0000000029a2c000 CR4: 00000000003506e0
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_crypto_clone_msg+0x91/0x160 net/tipc/crypto.c:1656
 tipc_crypto_xmit+0x1928/0x2300 net/tipc/crypto.c:1717
 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:early_section include/linux/mmzone.h:1764 [inline]
RIP: 0010:pfn_valid+0x1c5/0x420 include/linux/mmzone.h:1866
Code: e5 00 00 00 80 3d 63 86 0d 0c 01 0f 85 eb 00 00 00 e8 8f 4d a4 ff 4d 85 ff 0f 85 6b ff ff ff e9 55 ff ff ff 43 80 7c 25 00 00 <74> 08 4c 89 ff e8 31 c6 f5 ff 4d 8b 2f 4c 89 ee 48 83 e6 08 31 ff
RSP: 0000:ffffc90004ff7a00 EFLAGS: 00000246
RAX: ffffffff81dc887d RBX: ffffffff81dc87fd RCX: ffff88802efb8000
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000002 R08: dffffc0000000000 R09: fffffbfff2117049
R10: fffffbfff2117049 R11: 1ffffffff2117048 R12: dffffc0000000000
R13: 1ffff11027fff238 R14: 0000000000072e35 R15: ffff88813fff91c0
 page_table_check_set+0x25/0x6d0 mm/page_table_check.c:108
 page_table_check_pte_set include/linux/page_table_check.h:83 [inline]
 set_pte_at arch/x86/include/asm/pgtable.h:1009 [inline]
 do_set_pte+0x452/0x460 mm/memory.c:4426
 filemap_map_pages+0xcab/0x10d0 mm/filemap.c:3481
 do_fault_around mm/memory.c:4600 [inline]
 do_read_fault mm/memory.c:4626 [inline]
 do_fault mm/memory.c:4760 [inline]
 handle_pte_fault mm/memory.c:5031 [inline]
 __handle_mm_fault mm/memory.c:5173 [inline]
 handle_mm_fault+0x2889/0x3e70 mm/memory.c:5294
 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340
 handle_page_fault arch/x86/mm/fault.c:1431 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7fe602b565c0
Code: Unable to access opcode bytes at 0x7fe602b56596.
RSP: 002b:00007ffd1e3a39a8 EFLAGS: 00010216
RAX: 00000000000003c0 RBX: 0000000000000016 RCX: 0000000000000000
RDX: 0000000000000016 RSI: 00007fe602c1226e RDI: 00007ffd1e3a4240
RBP: 0000000000000016 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe602c12284
R13: 0000000000000016 R14: 00007ffd1e3a3f50 R15: 00007ffd1e3a3f50
 </TASK>
----------------
Code disassembly (best guess):
   0:	e5 00                	in     $0x0,%eax
   2:	00 00                	add    %al,(%rax)
   4:	80 3d 63 86 0d 0c 01 	cmpb   $0x1,0xc0d8663(%rip)        # 0xc0d866e
   b:	0f 85 eb 00 00 00    	jne    0xfc
  11:	e8 8f 4d a4 ff       	call   0xffa44da5
  16:	4d 85 ff             	test   %r15,%r15
  19:	0f 85 6b ff ff ff    	jne    0xffffff8a
  1f:	e9 55 ff ff ff       	jmp    0xffffff79
  24:	43 80 7c 25 00 00    	cmpb   $0x0,0x0(%r13,%r12,1)
* 2a:	74 08                	je     0x34 <-- trapping instruction
  2c:	4c 89 ff             	mov    %r15,%rdi
  2f:	e8 31 c6 f5 ff       	call   0xfff5c665
  34:	4d 8b 2f             	mov    (%r15),%r13
  37:	4c 89 ee             	mov    %r13,%rsi
  3a:	48 83 e6 08          	and    $0x8,%rsi
  3e:	31 ff                	xor    %edi,%edi