------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 32329 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 32329 Comm: syz.3.7405 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: 0018:ffffc900001e0828 EFLAGS: 00010246
RAX: c28357e804e6a200 RBX: 0000000000000002 RCX: ffff88807ca83b80
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc900001e0990 R08: dffffc0000000000 R09: fffff5200003c095
R10: fffff5200003c095 R11: 1ffff9200003c094 R12: ffff888058d11c40
R13: dffffc0000000000 R14: 0000000000000002 R15: ffff88807c6d5048
FS:  00007fc16a9806c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc01fce56c0 CR3: 000000005dd51000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000097 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:native_save_fl arch/x86/include/asm/irqflags.h:35 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline]
RIP: 0010:lock_is_held_type+0x64/0x190 kernel/locking/lockdep.c:5701
Code: 00 00 00 65 48 8b 1d 7b db f2 75 83 bb dc 0a 00 00 00 0f 85 df 00 00 00 41 89 f7 49 89 fe 48 c7 04 24 00 00 00 00 9c 8f 04 24 <4c> 8b 2c 24 fa 48 c7 c7 c0 0c 6c 8a e8 eb 12 00 00 65 ff 05 84 e5
RSP: 0018:ffffc900040178b8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88807ca83b80 RCX: ffff88807ca83b80
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8c92ab60
RBP: 00000000ffffffff R08: dffffc0000000000 R09: ffffc90004017ae0
R10: fffff52000802f63 R11: 1ffff92000802f5c R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff8c92ab60 R15: 00000000ffffffff
 lock_is_held include/linux/lockdep.h:283 [inline]
 __might_resched+0xf2/0x610 kernel/sched/core.c:9928
 __might_fault+0x6d/0x120 mm/memory.c:5850
 _copy_from_user+0x27/0x170 lib/usercopy.c:14
 copy_from_user include/linux/uaccess.h:161 [inline]
 copy_msghdr_from_user net/socket.c:2449 [inline]
 recvmsg_copy_msghdr net/socket.c:2704 [inline]
 ___sys_recvmsg+0x12b/0x510 net/socket.c:2776
 do_recvmmsg+0x359/0x7d0 net/socket.c:2874
 __sys_recvmmsg net/socket.c:2953 [inline]
 __do_sys_recvmmsg net/socket.c:2976 [inline]
 __se_sys_recvmmsg net/socket.c:2969 [inline]
 __x64_sys_recvmmsg+0x18d/0x240 net/socket.c:2969
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc169b8e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc16a980038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fc169db6080 RCX: 00007fc169b8e929
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007fc169c10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc169db6080 R15: 00007ffe04fedcb8
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	00 65 48             	add    %ah,0x48(%rbp)
   5:	8b 1d 7b db f2 75    	mov    0x75f2db7b(%rip),%ebx        # 0x75f2db86
   b:	83 bb dc 0a 00 00 00 	cmpl   $0x0,0xadc(%rbx)
  12:	0f 85 df 00 00 00    	jne    0xf7
  18:	41 89 f7             	mov    %esi,%r15d
  1b:	49 89 fe             	mov    %rdi,%r14
  1e:	48 c7 04 24 00 00 00 	movq   $0x0,(%rsp)
  25:	00
  26:	9c                   	pushf
  27:	8f 04 24             	pop    (%rsp)
* 2a:	4c 8b 2c 24          	mov    (%rsp),%r13 <-- trapping instruction
  2e:	fa                   	cli
  2f:	48 c7 c7 c0 0c 6c 8a 	mov    $0xffffffff8a6c0cc0,%rdi
  36:	e8 eb 12 00 00       	call   0x1326
  3b:	65                   	gs
  3c:	ff                   	.byte 0xff
  3d:	05                   	.byte 0x5
  3e:	84 e5                	test   %ah,%ch