------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 12203 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 12203 Comm: syz.6.1806 Not tainted 5.15.185-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 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:ffffc900000076a8 EFLAGS: 00010246
RAX: c3137d10203a7c00 RBX: 0000000000000002 RCX: ffff8880231e0000
RDX: 0000000000000100 RSI: 0000000000000100 RDI: 0000000000000000
RBP: ffffc90000007808 R08: dffffc0000000000 R09: fffff52000000e39
R10: fffff52000000e39 R11: 1ffff92000000e38 R12: ffff888079a83500
R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000
FS:  00007fcdbb3de6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb8e32a2ffc CR3: 0000000078c06000 CR4: 00000000003506f0
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:252 [inline]
 tipc_aead_encrypt net/tipc/crypto.c:832 [inline]
 tipc_crypto_xmit+0x1949/0x2560 net/tipc/crypto.c:1772
 tipc_crypto_clone_msg+0x91/0x160 net/tipc/crypto.c:1667
 tipc_crypto_xmit+0x1ac5/0x2560 net/tipc/crypto.c:1728
 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:rmqueue_pcplist mm/page_alloc.c:3711 [inline]
RIP: 0010:rmqueue mm/page_alloc.c:3742 [inline]
RIP: 0010:get_page_from_freelist+0x156c/0x1c60 mm/page_alloc.c:4189
Code: 01 00 00 00 00 00 00 9c 8f 84 24 80 01 00 00 f6 84 24 81 01 00 00 02 0f 85 dc 02 00 00 41 f7 c6 00 02 00 00 74 01 fb 4d 85 e4 <48> b9 00 00 00 00 00 fc ff df 4c 8b 74 24 38 0f 84 b9 01 00 00 4c
RSP: 0018:ffffc90003eaf280 EFLAGS: 00000286
RAX: c3137d10203a7c00 RBX: ffffffff8bbaf810 RCX: c3137d10203a7c00
RDX: dffffc0000000000 RSI: ffffffff8a0b11c0 RDI: ffffffff8a59a740
RBP: ffffc90003eaf490 R08: dffffc0000000000 R09: fffffbfff1ff362c
R10: fffffbfff1ff362c R11: 1ffffffff1ff362b R12: ffffea00016ad1c0
R13: 0000000000000000 R14: 0000000000000202 R15: ffffc90003eaf4e8
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5474
 alloc_pages_vma+0x393/0x7c0 mm/mempolicy.c:2146
 shmem_alloc_page mm/shmem.c:1586 [inline]
 shmem_alloc_and_acct_page+0x427/0xb70 mm/shmem.c:1611
 shmem_getpage_gfp+0x14f4/0x2d40 mm/shmem.c:1906
 shmem_getpage mm/shmem.c:151 [inline]
 shmem_write_begin+0xcd/0x1a0 mm/shmem.c:2474
 generic_perform_write+0x2aa/0x530 mm/filemap.c:3785
 __generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912
 generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944
 call_write_iter include/linux/fs.h:2172 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x712/0xd00 fs/read_write.c:594
 ksys_write+0x14d/0x250 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fcdbd5753df
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007fcdbb3dddf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000013bd7ef RCX: 00007fcdbd5753df
RDX: 00000000013bd7ef RSI: 00007fcdb2fbe000 RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000054ff
R10: 00000000000003c8 R11: 0000000000000293 R12: 0000000000000007
R13: 00007fcdbb3ddef0 R14: 00007fcdbb3ddeb0 R15: 00007fcdb2fbe000
 </TASK>
----------------
Code disassembly (best guess):
   0:	01 00                	add    %eax,(%rax)
   2:	00 00                	add    %al,(%rax)
   4:	00 00                	add    %al,(%rax)
   6:	00 9c 8f 84 24 80 01 	add    %bl,0x1802484(%rdi,%rcx,4)
   d:	00 00                	add    %al,(%rax)
   f:	f6 84 24 81 01 00 00 	testb  $0x2,0x181(%rsp)
  16:	02
  17:	0f 85 dc 02 00 00    	jne    0x2f9
  1d:	41 f7 c6 00 02 00 00 	test   $0x200,%r14d
  24:	74 01                	je     0x27
  26:	fb                   	sti
  27:	4d 85 e4             	test   %r12,%r12
* 2a:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx <-- trapping instruction
  31:	fc ff df
  34:	4c 8b 74 24 38       	mov    0x38(%rsp),%r14
  39:	0f 84 b9 01 00 00    	je     0x1f8
  3f:	4c                   	rex.WR