RBP: 0000000000000000 R08: 0000000000000002 R09: 00000000bb1414ac R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000009 R14: 0000000000000000 R15: 0000000000000000 ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 9577 at lib/refcount.c:28 refcount_warn_saturate+0x1dc/0x1f0 lib/refcount.c:28 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 9577 Comm: syz-executor327 Not tainted 5.5.0-rc6-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+0x197/0x210 lib/dump_stack.c:118 panic+0x2e3/0x75c kernel/panic.c:221 __warn.cold+0x2f/0x3e 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_warn_saturate+0x1dc/0x1f0 lib/refcount.c:28 Code: e9 d8 fe ff ff 48 89 df e8 c1 f8 16 fe e9 85 fe ff ff e8 a7 77 d8 fd 48 c7 c7 e0 44 71 88 c6 05 9e 86 db 06 01 e8 93 27 a9 fd <0f> 0b e9 ac fe ff ff 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 55 48 RSP: 0018:ffffc9000c067b00 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff815e5dd6 RDI: fffff5200180cf52 RBP: ffffc9000c067b10 R08: ffff8880a8630340 R09: ffffed1015d26621 R10: ffffed1015d26620 R11: ffff8880ae933107 R12: 0000000000000003 R13: ffff888090256000 R14: ffff8880a7e5c040 R15: ffff8880a7e5c044 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] __sk_destruct+0x6d8/0x7f0 net/core/sock.c:1723 sk_destruct+0xd5/0x110 net/core/sock.c:1739 __sk_free+0xfb/0x3f0 net/core/sock.c:1750 sk_free+0x83/0xb0 net/core/sock.c:1761 sock_put include/net/sock.h:1719 [inline] __tun_detach+0xbe0/0x1150 drivers/net/tun.c:728 tun_detach drivers/net/tun.c:740 [inline] tun_chr_close+0xe0/0x180 drivers/net/tun.c:3455 __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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xba9/0x2f50 kernel/exit.c:801 do_group_exit+0x135/0x360 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+0x44/0x50 kernel/exit.c:908 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441a48 Code: Bad RIP value. RSP: 002b:00007fffe55809a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000441a48 RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 RBP: 00000000004c8430 R08: 00000000000000e7 R09: ffffffffffffffd0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000006dba80 R14: 0000000000000000 R15: 0000000000000000 Kernel Offset: disabled Rebooting in 86400 seconds..