------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: lib/refcount.c:25 at refcount_warn_saturate+0x9f/0x110, CPU#0: ksoftirqd/0/15
Modules linked in:
CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:refcount_warn_saturate+0x9f/0x110
Code: eb 66 85 db 74 3e 83 fb 01 75 4c e8 3b 7b 13 fd 48 8d 3d 34 66 89 0b 67 48 0f b9 3a eb 4a e8 28 7b 13 fd 48 8d 3d 31 66 89 0b <67> 48 0f b9 3a eb 37 e8 15 7b 13 fd 48 8d 3d 2e 66 89 0b 67 48 0f
RSP: 0018:ffffc900001479e8 EFLAGS: 00010246
RAX: ffffffff84b22938 RBX: 0000000000000002 RCX: ffff888102eb1d80
RDX: 0000000000000100 RSI: ffffffff8f110b00 RDI: ffffffff903b8f70
RBP: 0000000000000000 R08: ffff888102eb1d80 R09: 0000000000000005
R10: 0000000000000004 R11: 0000000000000100 R12: dffffc0000000000
R13: 0000000000000001 R14: ffff888175bf8004 R15: ffff888175bf83c0
FS:  0000000000000000(0000) GS:ffff88818dc91000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faff7b45690 CR3: 000000011d9b0000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 sctp_generate_timeout_event+0x1c8/0x390
 call_timer_fn+0x192/0x5e0
 __run_timer_base+0x652/0x8b0
 run_timer_softirq+0xb7/0x170
 handle_softirqs+0x22a/0x840
 run_ksoftirqd+0x36/0x60
 smpboot_thread_fn+0x541/0xa50
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
