Backtrace

NMI watchdog: BUG: soft lockup - CPU#0 stuck for 21s! [smtpd:15182]
Modules linked in: xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 tun ip6t_rpfilter ipt_REJECT nf_reject_ipv4 ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter nls_utf8 isofs ext4 mbcache jbd2 ppdev pcspkr sg joydev parport_pc i2c_piix4 shpchp parport virtio_balloon nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sd_mod crc_t10dif sr_mod cdrom crct10dif_generic crct10dif_common ata_generic pata_acpi virtio_scsi bochs_drm drm_kms_helper
syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm ata_piix libata e1000 floppy serio_raw virtio_pci virtio_ring virtio i2c_core dm_mirror dm_region_hash dm_log dm_mod
CPU: 0 PID: 15182 Comm: smtpd Tainted: G             L ------------   3.10.0-693.el7.x86_64 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
task: ffff88007a0e2f70 ti: ffff880077fc4000 task.ti: ffff880077fc4000
RIP: 0010:[<ffffffffc0089ee7>]  [<ffffffffc0089ee7>] e1000_xmit_frame+0x947/0x1040 [e1000]
RSP: 0018:ffff880077fc78a8  EFLAGS: 00000286
RAX: ffffc90000403818 RBX: ffff880077fc7830 RCX: 0000000000000094
RDX: 0000000000000094 RSI: ffff8800360e6740 RDI: ffff88007ac52000
RBP: ffff880077fc7928 R08: 0000000000000100 R09: 0000000022100000
R10: 0000000080000000 R11: 0000000000000000 R12: ffff880079601310
R13: ffffffff81e87180 R14: ffffffffc052e280 R15: ffffffffc050274d
FS:  00007f72a5c74840(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000012fc510 CR3: 000000007a769000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Stack:
ffffffffc0189d06 ffff88007c253098 00000092c0189d06 0000000900000000
000000007b9e1300 ffff880000000000 ffffffff00000000 0000000100001000
ffff88007afd2af8 ffff88007ac52000 ffff88007c253000 ffff88007ac52000
Call Trace:
[<ffffffffc0189d06>] ? ipt_do_table+0x336/0x710 [ip_tables]
[<ffffffff81586771>] dev_hard_start_xmit+0x171/0x3b0
[<ffffffff815af50a>] sch_direct_xmit+0x11a/0x240
[<ffffffff81589566>] __dev_queue_xmit+0x226/0x550
[<ffffffff815898a0>] dev_queue_xmit+0x10/0x20
[<ffffffff815cfd3e>] ip_finish_output+0x52e/0x780
[<ffffffff815d0293>] ip_output+0x73/0xe0
[<ffffffff815cf810>] ? __ip_append_data.isra.48+0xa00/0xa00
[<ffffffff815cdf31>] ip_local_out_sk+0x31/0x40
[<ffffffff815ce2a3>] ip_queue_xmit+0x143/0x3a0
[<ffffffff815e7c0f>] tcp_transmit_skb+0x4cf/0x9b0
[<ffffffff815e824a>] tcp_write_xmit+0x15a/0xce0
[<ffffffff815e904e>] __tcp_push_pending_frames+0x2e/0xc0
[<ffffffff815d77dc>] tcp_push+0xec/0x120
[<ffffffff815db0f8>] tcp_sendmsg+0xc8/0xc30
[<ffffffff81606893>] inet_sendmsg+0x63/0xb0
[<ffffffff815697c7>] sock_aio_write+0x157/0x180
[<ffffffff8120026d>] do_sync_write+0x8d/0xd0
[<ffffffff81200e25>] vfs_write+0x1b5/0x1e0
[<ffffffff81201b3f>] SyS_write+0x7f/0xe0
[<ffffffff816b4fc9>] system_call_fastpath+0x16/0x1b
Code: 00 00 20 74 10 48 8b 83 00 03 00 00 f6 80 98 00 00 00 03 74 16 48 8b 5d c8 41 0f b7 47 2a 41 8b 57 18 48 03 83 90 0c 00 00 89 10 <48> 83 c4 58 31 c0 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 1f 84 00