R13: 0000000000000004 R14: 0000000000001380 R15: 00007ffda9f33fa8 ------------[ cut here ]------------ refcount_t: increment on 0; use-after-free. FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 WARNING: CPU: 0 PID: 4427 at lib/refcount.c:153 refcount_inc+0x47/0x50 lib/refcount.c:153 CPU: 1 PID: 4455 Comm: syzkaller083402 Not tainted 4.16.0-rc6+ #40 Kernel panic - not syncing: panic_on_warn set ... 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 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x8c0/0xa40 lib/fault-inject.c:149 should_failslab+0xec/0x120 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:422 [inline] slab_alloc mm/slab.c:3365 [inline] __do_kmalloc mm/slab.c:3703 [inline] __kmalloc+0x63/0x760 mm/slab.c:3714 kmalloc include/linux/slab.h:517 [inline] kzalloc include/linux/slab.h:701 [inline] register_shrinker+0x10e/0x2d0 mm/vmscan.c:268 sget_userns+0xbbf/0xe40 fs/super.c:520 mount_ns+0x6d/0x190 fs/super.c:1029 rpc_mount+0x9e/0xd0 net/sunrpc/rpc_pipe.c:1451 mount_fs+0x66/0x2d0 fs/super.c:1222 vfs_kern_mount.part.26+0xc6/0x4a0 fs/namespace.c:1037 vfs_kern_mount fs/namespace.c:2509 [inline] do_new_mount fs/namespace.c:2512 [inline] do_mount+0xea4/0x2bb0 fs/namespace.c:2842 SYSC_mount fs/namespace.c:3058 [inline] SyS_mount+0xab/0x120 fs/namespace.c:3035 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x442b59 RSP: 002b:00007ffda9f33e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442b59 RDX: 0000000020000480 RSI: 0000000020000180 RDI: 0000000020000100 RBP: 00007ffda9f34710 R08: 0000000000000000 R09: 0000000300000000 R10: 0000000000200000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000004 R14: 0000000000001380 R15: 00007ffda9f33fa8 CPU: 0 PID: 4427 Comm: syzkaller083402 Not tainted 4.16.0-rc6+ #40 ------------[ cut here ]------------ 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 panic+0x1e4/0x41c kernel/panic.c:183 refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 4431 at lib/refcount.c:187 refcount_sub_and_test+0x167/0x1b0 lib/refcount.c:187 Modules linked in: __warn+0x1dc/0x200 kernel/panic.c:547 CPU: 1 PID: 4431 Comm: syzkaller083402 Not tainted 4.16.0-rc6+ #40 report_bug+0x1f4/0x2b0 lib/bug.c:186 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 fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178 RSP: 0018:ffff8801b15ff728 EFLAGS: 00010286 fixup_bug arch/x86/kernel/traps.c:247 [inline] do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296 RAX: dffffc0000000008 RBX: 0000000000000000 RCX: ffffffff815ba4be RDX: 0000000000000000 RSI: 1ffff100362bfe95 RDI: 1ffff100362bfe6a RBP: ffff8801b15ff7b8 R08: 0000000000000000 R09: 0000000000000001 R10: ffff8801b15ff850 R11: 0000000000000000 R12: 1ffff100362bfee6 R13: 00000000ffffffff R14: 0000000000000001 R15: ffff8801b20a21c4 FS: 0000000000c35880(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffda9f34710 CR3: 00000001b1611002 CR4: 00000000001606e0 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:986 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 RIP: 0010:refcount_inc+0x47/0x50 lib/refcount.c:153 Call Trace: RSP: 0018:ffff8801b1037860 EFLAGS: 00010286 RAX: dffffc0000000008 RBX: ffff8801ac0c0184 RCX: ffffffff815ba4be RDX: 0000000000000000 RSI: 1ffff10036206ebc RDI: 1ffff10036206e91 RBP: ffff8801b1037868 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801b1037af8 refcount_dec_and_test+0x1a/0x20 lib/refcount.c:212 R13: ffff8801ac9c1513 R14: ffff8801ac0c0180 R15: ffff8801ac9c1501 put_net include/net/net_namespace.h:222 [inline] __sk_destruct+0x560/0x920 net/core/sock.c:1592 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:1660 [inline] tcp_close+0x967/0x1190 net/ipv4/tcp.c:2321 inet_create+0x47c/0xf50 net/ipv4/af_inet.c:320 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:427 __sock_create+0x4d4/0x850 net/socket.c:1285 sock_release+0x8d/0x1e0 net/socket.c:594 sock_close+0x16/0x20 net/socket.c:1149 sock_create net/socket.c:1325 [inline] SYSC_socket net/socket.c:1355 [inline] SyS_socket+0xeb/0x1d0 net/socket.c:1335 __fput+0x327/0x7e0 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 task_work_run+0x199/0x270 kernel/task_work.c:113 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 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4455d7 RSP: 002b:00007ffda9f33e68 EFLAGS: 00000206 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004455d7 RDX: 0000000000000006 RSI: 0000000000000001 RDI: 0000000000000002 RBP: 00007ffda9f33f80 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000006 R11: 0000000000000206 R12: 0000000000000002 R13: 0000000000000002 R14: 00000000000072a8 R15: 00007ffda9f33fa8 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x402880 RSP: 002b:00007ffda9f33e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000402880 RDX: 00000000000000e0 RSI: 00007ffda9f34740 RDI: 0000000000000003 RBP: 00007ffda9f33f80 R08: 00007ffda9f33e8c R09: 0000000000000001 R10: 00007ffda9f33f80 R11: 0000000000000246 R12: 00000000006cf4c0 R13: 00000000006cee40 R14: 0000000000001380 R15: 00007ffda9f33fa8 Code: 5e 41 5f 5d c3 e8 ea 3a be fe 80 3d 20 f4 84 05 00 75 1a e8 dc 3a be fe 48 c7 c7 e0 78 e5 86 c6 05 0b f4 84 05 01 e8 89 46 8e fe <0f> 0b 31 db eb a3 e8 be 3a be fe 83 fb ff 0f 85 63 ff ff ff 31 ---[ end trace 749adbee70856166 ]--- Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..