------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 8516 at lib/refcount.c:25 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25
Modules linked in:
CPU: 0 UID: 0 PID: 8516 Comm: syz.0.676 Not tainted 6.15.0-syzkaller-11802-g1af80d00e1e0 #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 a9 76 00 fd 5b 41 5e e9 3c 5b 50 fc cc e8 9b 76 00 fd c6 05 9a 09 cb 0a 01 90 48 c7 c7 c0 27 e2 8b e8 37 24 c4 fc 90 <0f> 0b 90 90 eb d7 e8 7b 76 00 fd c6 05 7b 09 cb 0a 01 90 48 c7 c7
RSP: 0018:ffffc90000007828 EFLAGS: 00010246
RAX: 6bc9906ce210c000 RBX: 0000000000000002 RCX: ffff888027531e00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc900000079b0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfaa44 R12: ffff88807c9a2080
R13: dffffc0000000000 R14: ffff88807c9a21ec R15: ffff8880682a0400
FS:  00007fd21851b6c0(0000) GS:ffff888125c5c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe8355d4f98 CR3: 0000000057d9e000 CR4: 0000000000350ef0
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+0x17e/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:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x5c/0xb0 kernel/rcu/tree.c:745
Code: c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 0c a7 7c 00 48 c7 c3 58 6f 9d 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 <75> 34 8b 03 65 ff 0d e9 18 f5 10 74 11 83 e0 04 c1 e8 02 5b 41 5e
RSP: 0018:ffffc9000bfa7260 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff8880b8632f58 RCX: 6bc9906ce210c000
RDX: 0000000000000000 RSI: ffffffff8be27220 RDI: ffffffff8be271e0
RBP: ffffc9000bfa74b8 R08: ffffffff8fa0f5f7 R09: 1ffffffff1f41ebe
R10: dffffc0000000000 R11: fffffbfff1f41ebf R12: ffff88802e425a00
R13: dffffc0000000000 R14: ffffffff8db9fc60 R15: dffffc0000000000
 trace_sched_exit_tp+0x38/0x120 include/trace/events/sched.h:888
 __schedule+0x1713/0x4d00 kernel/sched/core.c:6791
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 unix_wait_for_peer+0x1e9/0x2e0 net/unix/af_unix.c:1585
 unix_dgram_sendmsg+0xb1f/0x1870 net/unix/af_unix.c:2187
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:727
 ____sys_sendmsg+0x52d/0x830 net/socket.c:2566
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620
 __sys_sendmmsg+0x227/0x430 net/socket.c:2709
 __do_sys_sendmmsg net/socket.c:2736 [inline]
 __se_sys_sendmmsg net/socket.c:2733 [inline]
 __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2733
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd21778e929
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:00007fd21851b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fd2179b5fa0 RCX: 00007fd21778e929
RDX: 0000000000000651 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007fd217810ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd2179b5fa0 R15: 00007ffe9e076ec8
 </TASK>
----------------
Code disassembly (best guess):
   0:	c1 e8 03             	shr    $0x3,%eax
   3:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1)
   8:	74 08                	je     0x12
   a:	4c 89 f7             	mov    %r14,%rdi
   d:	e8 0c a7 7c 00       	call   0x7ca71e
  12:	48 c7 c3 58 6f 9d 92 	mov    $0xffffffff929d6f58,%rbx
  19:	49 03 1e             	add    (%r14),%rbx
  1c:	48 89 d8             	mov    %rbx,%rax
  1f:	48 c1 e8 03          	shr    $0x3,%rax
  23:	42 0f b6 04 38       	movzbl (%rax,%r15,1),%eax
  28:	84 c0                	test   %al,%al
* 2a:	75 34                	jne    0x60 <-- trapping instruction
  2c:	8b 03                	mov    (%rbx),%eax
  2e:	65 ff 0d e9 18 f5 10 	decl   %gs:0x10f518e9(%rip)        # 0x10f5191e
  35:	74 11                	je     0x48
  37:	83 e0 04             	and    $0x4,%eax
  3a:	c1 e8 02             	shr    $0x2,%eax
  3d:	5b                   	pop    %rbx
  3e:	41 5e                	pop    %r14