------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 8984 at lib/refcount.c:190 refcount_sub_and_test_checked lib/refcount.c:190 [inline]
WARNING: CPU: 1 PID: 8984 at lib/refcount.c:190 refcount_sub_and_test_checked+0x1d0/0x200 lib/refcount.c:180
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 8984 Comm: syz-executor828 Not tainted 5.4.0-rc7-next-20191115 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x35 kernel/panic.c:582
 report_bug+0x289/0x300 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 fixup_bug arch/x86/kernel/traps.c:169 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:refcount_sub_and_test_checked lib/refcount.c:190 [inline]
RIP: 0010:refcount_sub_and_test_checked+0x1d0/0x200 lib/refcount.c:180
Code: 1d cc c7 7c 06 31 ff 89 de e8 ec 0e 2c fe 84 db 75 94 e8 a3 0d 2c fe 48 c7 c7 80 33 e7 87 c6 05 ac c7 7c 06 01 e8 d8 0a fd fd <0f> 0b e9 75 ff ff ff e8 84 0d 2c fe e9 6e ff ff ff 48 89 df e8 f7
RSP: 0018:ffff88808ed07cb0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815d6fe6 RDI: ffffed1011da0f88
RBP: ffff88808ed07d48 R08: ffff888099578100 R09: ffffed1015d245c9
R10: ffffed1015d245c8 R11: ffff8880ae922e43 R12: 00000000ffffffff
R13: 0000000000000001 R14: ffff88808ed07d20 R15: 0000000000000000
 refcount_dec_and_test_checked+0x1b/0x20 lib/refcount.c:220
 sock_put include/net/sock.h:1728 [inline]
 smc_release+0x236/0x3e0 net/smc/af_smc.c:201
 __sock_release+0xce/0x280 net/socket.c:591
 sock_close+0x1e/0x30 net/socket.c:1269
 __fput+0x2ff/0x890 fs/file_table.c:280
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x676/0x790 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x403de0
Code: 01 f0 ff ff 0f 83 c0 0f 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 6d ff 2d 00 00 75 14 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 94 0f 00 00 c3 48 83 ec 08 e8 fa 04 00 00
RSP: 002b:00007ffd8e9e9008 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000403de0
RDX: 0000000000000017 RSI: 0000000000000006 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000004 R09: 00000000000003e8
R10: 0000000020000240 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000405290 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..