------------[ cut here ]------------ refcount_t: increment on 0; use-after-free. WARNING: CPU: 0 PID: 15044 at lib/refcount.c:156 refcount_inc_checked lib/refcount.c:156 [inline] WARNING: CPU: 0 PID: 15044 at lib/refcount.c:156 refcount_inc_checked+0x61/0x70 lib/refcount.c:154 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 15044 Comm: syz-executor505 Not tainted 5.3.0-rc1+ #86 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+0x172/0x1f0 lib/dump_stack.c:113 panic+0x2dc/0x755 kernel/panic.c:219 __warn.cold+0x20/0x4c kernel/panic.c:576 report_bug+0x263/0x2b0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:179 [inline] fixup_bug arch/x86/kernel/traps.c:174 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1026 RIP: 0010:refcount_inc_checked lib/refcount.c:156 [inline] RIP: 0010:refcount_inc_checked+0x61/0x70 lib/refcount.c:154 Code: 1d 48 87 64 06 31 ff 89 de e8 cb a3 35 fe 84 db 75 dd e8 82 a2 35 fe 48 c7 c7 c0 02 c6 87 c6 05 28 87 64 06 01 e8 67 05 07 fe <0f> 0b eb c1 90 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 41 57 41 RSP: 0018:ffff8880ae809bf0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000100 RSI: ffffffff815c5bd6 RDI: ffffed1015d01370 RBP: ffff8880ae809c00 R08: ffff88809af3c600 R09: ffffed1015d040f1 R10: ffffed1015d040f0 R11: ffff8880ae820787 R12: ffff888093152340 R13: ffff888093152328 R14: ffff8880823e8248 R15: ffff8880823e8220 sock_hold include/net/sock.h:649 [inline] sk_add_node include/net/sock.h:701 [inline] nr_insert_socket+0x2d/0xe0 net/netrom/af_netrom.c:137 nr_rx_frame+0x1605/0x1e73 net/netrom/af_netrom.c:1023 nr_loopback_timer+0x7b/0x170 net/netrom/nr_loopback.c:59 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1322 expire_timers kernel/time/timer.c:1366 [inline] __run_timers kernel/time/timer.c:1685 [inline] __run_timers kernel/time/timer.c:1653 [inline] run_timer_softirq+0x697/0x17a0 kernel/time/timer.c:1698 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:537 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1095 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:828 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:768 [inline] RIP: 0010:console_unlock+0xbc7/0xf10 kernel/printk/printk.c:2471 Code: d2 88 48 c1 e8 03 42 80 3c 30 00 0f 85 e4 02 00 00 48 83 3d 9a f8 76 07 00 0f 84 91 01 00 00 e8 2f b0 16 00 48 8b 7d 98 57 9d <0f> 1f 44 00 00 e9 6d ff ff ff e8 1a b0 16 00 48 8b 7d 08 c7 05 9c RSP: 0018:ffff8880874ef9d0 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffff88809af3c600 RBX: 0000000000000200 RCX: 1ffffffff134b2be RDX: 0000000000000000 RSI: ffffffff815bf901 RDI: 0000000000000293 RBP: ffff8880874efa58 R08: ffff88809af3c600 R09: fffffbfff134ac80 R10: fffffbfff134ac7f R11: ffffffff89a563ff R12: 0000000000000000 R13: ffffffff84336760 R14: dffffc0000000000 R15: ffffffff893c9c90 vprintk_emit+0x2a0/0x700 kernel/printk/printk.c:1986 vprintk_default+0x28/0x30 kernel/printk/printk.c:2013 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:386 printk+0xba/0xed kernel/printk/printk.c:2046 __ip_vs_ftp_init.cold+0x5b/0x6a net/netfilter/ipvs/ip_vs_ftp.c:594 ops_init+0xb3/0x420 net/core/net_namespace.c:137 setup_net+0x2d2/0x890 net/core/net_namespace.c:334 copy_net_ns+0x290/0x41f net/core/net_namespace.c:475 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:103 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:202 ksys_unshare+0x444/0x980 kernel/fork.c:2831 __do_sys_unshare kernel/fork.c:2899 [inline] __se_sys_unshare kernel/fork.c:2897 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2897 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x44bd19 Code: e8 7c e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 1b 05 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f5fb2b77cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00000000006e8a18 RCX: 000000000044bd19 RDX: 000000000044bd19 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00000000006e8a10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006e8a1c R13: 00007ffe99a522cf R14: 00007f5fb2b789c0 R15: 20c49ba5e353f7cf Kernel Offset: disabled Rebooting in 86400 seconds..