R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000003 R14: 0000000000001380 R15: 00007fff3b87f548 ------------[ cut here ]------------ refcount_t: increment on 0; use-after-free. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 4439 at lib/refcount.c:153 refcount_inc+0x47/0x50 lib/refcount.c:153 refcount_t: underflow; use-after-free. Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 4439 Comm: syzkaller848704 Not tainted 4.16.0-rc6+ #43 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 WARNING: CPU: 1 PID: 4441 at lib/refcount.c:187 refcount_sub_and_test+0x167/0x1b0 lib/refcount.c:187 Modules linked in: panic+0x1e4/0x41c kernel/panic.c:183 CPU: 1 PID: 4441 Comm: syzkaller848704 Not tainted 4.16.0-rc6+ #43 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:refcount_sub_and_test+0x167/0x1b0 lib/refcount.c:187 RSP: 0018:ffff8801b52d7728 EFLAGS: 00010286 RAX: dffffc0000000008 RBX: 0000000000000000 RCX: ffffffff815b423e RDX: 0000000000000000 RSI: 1ffff10036a5ae95 RDI: 1ffff10036a5ae6a RBP: ffff8801b52d77b8 R08: 0000000000000000 R09: 0000000000000001 R10: ffff8801b52d7850 R11: 0000000000000000 R12: 1ffff10036a5aee6 __warn+0x1dc/0x200 kernel/panic.c:547 R13: 00000000ffffffff R14: 0000000000000001 R15: ffff8801ada18144 FS: 0000000001a59880(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000 report_bug+0x1f4/0x2b0 lib/bug.c:186 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 fixup_bug.part.10+0x37/0x80 arch/x86/kernel/traps.c:178 CR2: 00007fff3b880000 CR3: 00000001adaaf004 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 fixup_bug arch/x86/kernel/traps.c:247 [inline] do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: refcount_dec_and_test+0x1a/0x20 lib/refcount.c:212 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 put_net include/net/net_namespace.h:222 [inline] __sk_destruct+0x560/0x920 net/core/sock.c:1592 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:986 RIP: 0010:refcount_inc+0x47/0x50 lib/refcount.c:153 RSP: 0018:ffff8801add3f860 EFLAGS: 00010286 RAX: dffffc0000000008 RBX: ffff8801add320c4 RCX: ffffffff815b423e RDX: 0000000000000000 RSI: 1ffff10035ba7ebc RDI: 1ffff10035ba7e91 RBP: ffff8801add3f868 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801add3faf8 R13: ffff8801d911aa93 R14: ffff8801add320c0 R15: ffff8801d911ab01 get_net include/net/net_namespace.h:204 [inline] sk_alloc+0x3f9/0x1440 net/core/sock.c:1540 sk_destruct+0x47/0x80 net/core/sock.c:1601 __sk_free+0xf1/0x2b0 net/core/sock.c:1612 sk_free+0x2a/0x40 net/core/sock.c:1623 sock_put include/net/sock.h:1664 [inline] tcp_close+0x967/0x1190 net/ipv4/tcp.c:2329 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:427 sock_release+0x8d/0x1e0 net/socket.c:594 sock_close+0x16/0x20 net/socket.c:1149 __fput+0x327/0x7e0 fs/file_table.c:209 inet_create+0x47c/0xf50 net/ipv4/af_inet.c:320 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x199/0x270 kernel/task_work.c:113 __sock_create+0x4d4/0x850 net/socket.c:1285 sock_create net/socket.c:1325 [inline] SYSC_socket net/socket.c:1355 [inline] SyS_socket+0xeb/0x1d0 net/socket.c:1335 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x275/0x2f0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:265 [inline] do_syscall_64+0x6ec/0x940 arch/x86/entry/common.c:292 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x402480 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RSP: 002b:00007fff3b87f408 EFLAGS: 00000246 RIP: 0033:0x4451d7 ORIG_RAX: 0000000000000003 RSP: 002b:00007fff3b87f408 EFLAGS: 00000206 ORIG_RAX: 0000000000000029 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000402480 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00000000004451d7 RDX: 00000000000000e0 RSI: 00007fff3b87fce0 RDI: 0000000000000003 RDX: 0000000000000006 RSI: 0000000000000001 RDI: 0000000000000002 RBP: 00007fff3b87f520 R08: 0000000000000000 R09: 0000000000000001 RBP: 00007fff3b87f520 R08: 00007fff3b87f42c R09: 0000000000000001 R10: 00007fff3b87f520 R11: 0000000000000246 R12: 00000000006cf4c0 R10: 000000000000000a R11: 0000000000000206 R12: 0000000000000003 R13: 0000000000000003 R14: 0000000000006724 R15: 00007fff3b87f548 R13: 00000000006cee40 R14: 0000000000001380 R15: 00007fff3b87f548 Code: 5e 41 5f 5d c3 e8 9a 26 5e fe 80 3d fb 42 d6 05 00 75 1a e8 8c 26 5e fe 48 c7 c7 a0 a7 75 87 c6 05 e6 42 d6 05 01 e8 d9 33 2e fe <0f> 0b 31 db eb a3 e8 6e 26 5e fe 83 fb ff 0f 85 63 ff ff ff 31 ---[ end trace c7b69e3df19fd10a ]--- Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..