IPVS: ftp: loaded support on port[0] = 21
netlink: 16 bytes leftover after parsing attributes in process `syz-executor347'.
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 9447 at lib/refcount.c:28 refcount_warn_saturate+0x1d1/0x1e0 lib/refcount.c:28
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 9447 Comm: syz-executor347 Not tainted 5.6.0-rc5-syzkaller #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+0x188/0x20d lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x35 kernel/panic.c:582
 report_bug+0x27b/0x2f0 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+0x12b/0x220 arch/x86/kernel/traps.c:267
 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:refcount_warn_saturate+0x1d1/0x1e0 lib/refcount.c:28
Code: e9 db fe ff ff 48 89 df e8 6c 06 20 fe e9 8a fe ff ff e8 32 48 e3 fd 48 c7 c7 40 aa 51 88 c6 05 a4 5d d2 06 01 e8 77 58 b5 fd <0f> 0b e9 af fe ff ff 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55
RSP: 0018:ffffc90007807d38 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815bf511 RDI: fffff52000f00f99
RBP: 0000000000000003 R08: ffff888094102440 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888093b3a040
R13: ffff888093b3a044 R14: 00000000000002ac R15: ffff888096522b80
 refcount_sub_and_test include/linux/refcount.h:261 [inline]
 refcount_dec_and_test include/linux/refcount.h:281 [inline]
 put_net include/net/net_namespace.h:259 [inline]
 free_nsproxy+0x445/0x4a0 kernel/nsproxy.c:206
 switch_task_namespaces+0xaa/0xc0 kernel/nsproxy.c:252
 do_exit+0xb2f/0x2dd0 kernel/exit.c:800
 do_group_exit+0x125/0x340 kernel/exit.c:899
 __do_sys_exit_group kernel/exit.c:910 [inline]
 __se_sys_exit_group kernel/exit.c:908 [inline]
 __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:908
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x43f998
Code: Bad RIP value.
RSP: 002b:00007fff31404d28 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000043f998
RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001
RBP: 00000000004bfa10 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 0000000120080522 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006d11c0 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..