------------[ cut here ]------------ kernel BUG at net/ipv4/tcp_output.c:2591! invalid opcode: 0000 [#1] PREEMPT SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 6596 Comm: syz-executor154 Not tainted 4.4.132-g4b08356 #50 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801c8240000 task.stack: ffff8801c1e78000 RIP: 0010:[] [] __tcp_retransmit_skb+0x17e5/0x1860 net/ipv4/tcp_output.c:2591 RSP: 0018:ffff8801db207b60 EFLAGS: 00010206 RAX: ffff8801c8240000 RBX: ffff8801c86daf28 RCX: ffff8800b3370244 RDX: 0000000000000100 RSI: ffffffff8328aff5 RDI: ffff8801c86daf2c RBP: ffff8801db207c08 R08: 000000212202db5e R09: 0000000000000006 R10: ffffed0043fffa01 R11: 0000000000000001 R12: 000000004b11c8b4 R13: 000000004b02e3fc R14: ffff8801c86daf00 R15: ffff8800b3370000 FS: 00007f6b1eb02700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fffc5facfcc CR3: 00000000b328d000 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: 000000212202db5e ffffffffffffffff 000000212224b80d ffff8800b3370000 0000000000000004 ffff8800b3370854 00000000ffffffff ffff8800b3370244 ffff8801db207bc8 ffffffff833a936e ffff8800b3370000 ffffffff833a8f50 Call Trace: [] tcp_retransmit_skb+0x23/0x2c0 net/ipv4/tcp_output.c:2664 [] tcp_retransmit_timer+0x7bd/0x1ed0 net/ipv4/tcp_timer.c:461 [] tcp_write_timer_handler+0x1f1/0x6f0 net/ipv4/tcp_timer.c:543 [] tcp_write_timer+0xba/0xd0 net/ipv4/tcp_timer.c:561 [] call_timer_fn+0x18c/0x870 kernel/time/timer.c:1185 [] __run_timers kernel/time/timer.c:1261 [inline] [] run_timer_softirq+0x642/0xb90 kernel/time/timer.c:1444 [] __do_softirq+0x22c/0xa1a kernel/softirq.c:273 [] invoke_softirq kernel/softirq.c:350 [inline] [] irq_exit+0x10d/0x140 kernel/softirq.c:391 [] exiting_irq arch/x86/include/asm/apic.h:653 [inline] [] smp_apic_timer_interrupt+0x81/0xa0 arch/x86/kernel/apic/apic.c:926 [] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:741 [] print_context_stack+0x4b/0xd0 arch/x86/kernel/dumpstack.c:107 [] dump_trace+0x17a/0x360 arch/x86/kernel/dumpstack_64.c:243 [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:616 [] kasan_krealloc+0x64/0x80 mm/kasan/kasan.c:654 [] ksize+0x8a/0xf0 mm/slub.c:3727 [] __do_krealloc mm/slab_common.c:1193 [inline] [] __krealloc+0x27/0xb0 mm/slab_common.c:1222 [] __nf_ct_ext_add_length+0x223/0xb50 net/netfilter/nf_conntrack_extend.c:104 [] nf_ct_nat_ext_add+0xf6/0x130 net/netfilter/nf_nat_core.c:373 [] nf_nat_ipv4_fn+0x122/0x690 net/ipv4/netfilter/nf_nat_l3proto_ipv4.c:284 [] nf_nat_ipv4_local_fn+0x122/0x470 net/ipv4/netfilter/nf_nat_l3proto_ipv4.c:422 [] iptable_nat_ipv4_local_fn+0x2c/0x40 net/ipv4/netfilter/iptable_nat.c:64 [] nf_iterate+0x182/0x210 net/netfilter/core.c:274 [] nf_hook_slow+0x1b6/0x340 net/netfilter/core.c:306 [] nf_hook_thresh include/linux/netfilter.h:187 [inline] [] nf_hook include/linux/netfilter.h:197 [inline] [] __ip_local_out+0x2b4/0x440 net/ipv4/ip_output.c:108 [] ip_local_out+0x29/0x180 net/ipv4/ip_output.c:117 [] ip_queue_xmit+0x88e/0x1ab0 net/ipv4/ip_output.c:461 [] tcp_transmit_skb+0x1642/0x2bf0 net/ipv4/tcp_output.c:1029 [] tcp_connect+0x1d59/0x2c60 net/ipv4/tcp_output.c:3276 [] tcp_v4_connect+0xf31/0x1890 net/ipv4/tcp_ipv4.c:246 [] __inet_stream_connect+0x2a9/0xc30 net/ipv4/af_inet.c:615 [] inet_stream_connect+0x55/0xa0 net/ipv4/af_inet.c:676 [] SYSC_connect+0x1b8/0x300 net/socket.c:1557 [] SyS_connect+0x24/0x30 net/socket.c:1538 [] entry_SYSCALL_64_fastpath+0x22/0x9e Code: e0 26 fe e9 aa ed ff ff e8 89 e0 26 fe e9 4f f5 ff ff e8 7f e0 26 fe e9 6b f5 ff ff e8 95 e0 26 fe e9 d3 ef ff ff e8 fb 61 0c fe <0f> 0b 4c 89 f7 e8 81 e0 26 fe e9 d9 ec ff ff e8 f7 e0 26 fe e9 RIP [] __tcp_retransmit_skb+0x17e5/0x1860 net/ipv4/tcp_output.c:2591 RSP ---[ end trace f8ddff88097077a9 ]---