We're also experiencing the same issue when booting the trusty installer on a Dell PowerEdge R610 with a Dell SAS 6/iR controller (LSI SAS1068E), resulting in the inability to install/run this system. This is an extremely popular controller, prevalent in a signifcant portion of Dell systems (or systems in general) out there, so this is a pretty serious bug for Trusty.

The kernel actually oopses, here's the relevant lines from dmesg:
[   80.845434] Fusion MPT SAS Host driver 3.04.20
[   80.845640] mptbase: ioc0: Initiating bringup
[   80.987894] ipmi_si ipmi_si.0: Found new BMC (man_id: 0x0002a2, prod_id: 0x0100, dev_id: 0x2)
[   80.987908] ipmi_si ipmi_si.0: IPMI kcs interface initialized
[   81.550894] ioc0: LSISAS1068E B3: Capabilities={Initiator}
[  111.853426] scsi0: error handler thread failed to spawn, error = -12
[  111.853431] mptsas: ioc0: WARNING - Unable to register controller with SCSI subsystem
[  111.853441] BUG: unable to handle kernel NULL pointer dereference at 0000000000000060
[  111.861275] IP: [<ffffffff81710382>] mutex_lock+0x12/0x2f
[  111.866676] PGD 421531067 PUD 4207f2067 PMD 0
[  111.871137] Oops: 0002 [#1] SMP
[  111.874375] Modules linked in: mptsas(F+) mptscsih(F) mptbase(F) scsi_transport_sas(F) ipmi_)
[  111.899462] CPU: 0 PID: 9847 Comm: systemd-udevd Tainted: GF            3.13.0-8-generic #27u
[  111.908489] Hardware name: Dell Inc. PowerEdge R610/0F0XJ6, BIOS 3.0.0 01/31/2011
[  111.915955] task: ffff880420734800 ti: ffff880422356000 task.ti: ffff880422356000
[  111.923496] RIP: 0010:[<ffffffff81710382>]  [<ffffffff81710382>] mutex_lock+0x12/0x2f
[  111.931319] RSP: 0018:ffff880422357b10  EFLAGS: 00010246
[  111.936619] RAX: 0000000000000000 RBX: 0000000000000060 RCX: 0000000000000006
[  111.943737] RDX: 0000000000000007 RSI: 00000000f0aef0ac RDI: 0000000000000060
[  111.950856] RBP: ffff880422357b18 R08: 0000000000000086 R09: 000000000000037f
[  111.957974] R10: 0000000000000000 R11: ffff8804223578ae R12: 0000000000000060
[  111.965091] R13: ffff880423e9f000 R14: ffff880423e9f098 R15: ffffffffa01063a0
[  111.972210] FS:  00007fd5221af7c0(0000) GS:ffff88042fc00000(0000) knlGS:0000000000000000
[  111.980283] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  111.986014] CR2: 0000000000000060 CR3: 000000042144f000 CR4: 00000000000007f0
[  111.993132] Stack:
[  111.995135]  0000000000000000 ffff880422357b40 ffffffff814c842d ffff880423da6000
[  112.002549]  0000000000000000 ffff880423e9f000 ffff880422357b70 ffffffffa00ee2a1
[  112.009966]  ffff880423da6000 00000000ffffffff ffff880423e9f000 ffff880423e9f098
[  112.017384] Call Trace:
[  112.019830]  [<ffffffff814c842d>] scsi_remove_host+0x1d/0x120
[  112.025565]  [<ffffffffa00ee2a1>] mptscsih_remove+0x31/0xc0 [mptscsih]
[  112.032082]  [<ffffffffa0100259>] mptsas_probe+0x419/0x5a0 [mptsas]
[  112.038337]  [<ffffffff8139c775>] local_pci_probe+0x45/0xa0
[  112.043897]  [<ffffffff8139da15>] ? pci_match_device+0xc5/0xd0
[  112.049718]  [<ffffffff8139db39>] pci_device_probe+0xd9/0x130
[  112.055454]  [<ffffffff814839b5>] driver_probe_device+0x125/0x3b0
[  112.061534]  [<ffffffff81483d13>] __driver_attach+0x93/0xa0
[  112.067094]  [<ffffffff81483c80>] ? __device_attach+0x40/0x40
[  112.072829]  [<ffffffff81481923>] bus_for_each_dev+0x63/0xa0
[  112.078475]  [<ffffffff8148336e>] driver_attach+0x1e/0x20
[  112.083861]  [<ffffffff81482f50>] bus_add_driver+0x180/0x250
[  112.089508]  [<ffffffffa0065000>] ? 0xffffffffa0064fff
[  112.094634]  [<ffffffff81484394>] driver_register+0x64/0xf0
[  112.100195]  [<ffffffffa0065000>] ? 0xffffffffa0064fff
[  112.105322]  [<ffffffff8139c10c>] __pci_register_driver+0x4c/0x50
[  112.111404]  [<ffffffffa006511e>] mptsas_init+0x11e/0x1000 [mptsas]
[  112.117658]  [<ffffffff8100214a>] do_one_initcall+0xfa/0x1b0
[  112.123308]  [<ffffffff81056d23>] ? set_memory_nx+0x43/0x50
[  112.128871]  [<ffffffff810df8dd>] load_module+0x12dd/0x1b40
[  112.134432]  [<ffffffff810db360>] ? store_uevent+0x40/0x40
[  112.139908]  [<ffffffff810e02b6>] SyS_finit_module+0x86/0xb0
[  112.145558]  [<ffffffff8171a73f>] tracesys+0xe1/0xe6
[  112.150508] Code: 05 e1 99 ff e9 40 ff ff ff b8 01 00 00 00 e9 8c fe ff ff 66 0f 1f 44 00 00
[  112.169922] RIP  [<ffffffff81710382>] mutex_lock+0x12/0x2f
[  112.175405]  RSP <ffff880422357b10>
[  112.178881] CR2: 0000000000000060
[  112.182208] ---[ end trace 00e5da911f36281b ]---