In the meantime I tested with 3.2.64, 3.4.104, 3.10.60 and 3.12.32 and had no problem, i.e. GNU `ddrescue ` 1.17 processes the device without kernel panic (1.5 TB with > 7000 errors recognized and copied on a damaged device).

In 3.14.24 I don't get a kernel panic, but `ddrescue` get stuck at reading a damaged block while `dmesg` shows 

    [ 2074.174135]  sdh: sdh1 sdh9
    [ 2462.587818] usb 4-1.3.1.3: reset SuperSpeed USB device number 9 using xhci_hcd
    [ 2462.603164] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff88041d586d80
    [ 2462.603168] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff88041d586dc0
    [ 2502.601314] usb 4-1.3.1.3: reset SuperSpeed USB device number 9 using xhci_hcd
    [ 2502.616594] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff88041d586d80
    [ 2502.616602] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff88041d586dc0
    [ 2647.252571] INFO: task usb-storage:604 blocked for more than 120 seconds.
    [ 2647.252580]       Tainted: PF       W  O 3.14.24-031424-generic #201411141736
    [ 2647.252591] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    [ 2647.252593] usb-storage     D ffffffff81811ae0     0   604      2 0x00000000
    [ 2647.252596]  ffff88041cb55af8 0000000000000046 ffff88041cb55af8 ffff88041cb55fd8
    [ 2647.252599]  0000000000014540 0000000000014540 ffffffff81c144a0 ffff88041cb0a7c0
    [ 2647.252601]  0000000100000000 ffff880422b9d808 7fffffffffffffff 7fffffffffffffff
    [ 2647.252603] Call Trace:
    [ 2647.252609]  [<ffffffff8177a739>] schedule+0x29/0x70
    [ 2647.252612]  [<ffffffff817799e5>] schedule_timeout+0x1e5/0x250
    [ 2647.252616]  [<ffffffff8156bd58>] ? usb_hcd_submit_urb+0x88/0x1b0
    [ 2647.252618]  [<ffffffff8177b9d7>] wait_for_completion+0xa7/0x160
    [ 2647.252620]  [<ffffffff8156cece>] ? usb_alloc_urb+0x1e/0x50
    [ 2647.252624]  [<ffffffff810a4da0>] ? try_to_wake_up+0x210/0x210
    [ 2647.252626]  [<ffffffff8156f14a>] usb_sg_wait+0x13a/0x1f0
    [ 2647.252646]  [<ffffffffa019f531>] usb_stor_bulk_transfer_sglist.part.5+0x51/0xc0 [usb_storage]
    [ 2647.252651]  [<ffffffffa019f637>] usb_stor_bulk_transfer_sglist+0x97/0xa0 [usb_storage]
    [ 2647.252655]  [<ffffffffa019f66e>] usb_stor_bulk_srb+0x2e/0x50 [usb_storage]
    [ 2647.252659]  [<ffffffffa019f7d7>] usb_stor_Bulk_transport+0x147/0x3f0 [usb_storage]
    [ 2647.252662]  [<ffffffff817799e5>] ? schedule_timeout+0x1e5/0x250
    [ 2647.252666]  [<ffffffffa01a006e>] usb_stor_invoke_transport+0x3e/0x570 [usb_storage]
    [ 2647.252668]  [<ffffffff8177b1bd>] ? wait_for_completion_interruptible+0xcd/0x1c0
    [ 2647.252672]  [<ffffffffa019ee5e>] usb_stor_transparent_scsi_command+0xe/0x10 [usb_storage]
    [ 2647.252676]  [<ffffffffa01a172a>] usb_stor_control_thread+0x1ba/0x310 [usb_storage]
    [ 2647.252681]  [<ffffffffa01a1570>] ? fill_inquiry_response+0x20/0x20 [usb_storage]
    [ 2647.252683]  [<ffffffff81093079>] kthread+0xc9/0xe0
    [ 2647.252685]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0
    [ 2647.252687]  [<ffffffff817875bc>] ret_from_fork+0x7c/0xb0
    [ 2647.252689]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0
    [ 2767.388999] INFO: task scsi_eh_10:602 blocked for more than 120 seconds.
    [ 2767.389003]       Tainted: PF       W  O 3.14.24-031424-generic #201411141736
    [ 2767.389004] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    [ 2767.389005] scsi_eh_10      D ffffffff81811ae0     0   602      2 0x00000000
    [ 2767.389008]  ffff88041cb51c78 0000000000000046 0000000000000000 ffff88041cb51fd8
    [ 2767.389011]  0000000000014540 0000000000014540 ffff880428e693e0 ffff88041cb093e0
    [ 2767.389013]  000000000000000e ffff880422b9d6f0 ffff880422b9d6f4 00000000ffffffff
    [ 2767.389015] Call Trace:
    [ 2767.389020]  [<ffffffff8177a739>] schedule+0x29/0x70
    [ 2767.389022]  [<ffffffff8177aa5e>] schedule_preempt_disabled+0xe/0x10
    [ 2767.389024]  [<ffffffff8177c894>] __mutex_lock_slowpath+0x114/0x1b0
    [ 2767.389026]  [<ffffffff8177c953>] mutex_lock+0x23/0x37
    [ 2767.389043]  [<ffffffffa019e9bb>] device_reset+0x2b/0x60 [usb_storage]
    [ 2767.389046]  [<ffffffff815077ee>] scsi_try_bus_device_reset+0x2e/0x60
    [ 2767.389047]  [<ffffffff8150a37f>] scsi_eh_bus_device_reset+0xdf/0x270
    [ 2767.389049]  [<ffffffff8150a663>] ? scsi_eh_stu+0x153/0x280
    [ 2767.389051]  [<ffffffff8150a7de>] scsi_eh_ready_devs+0x4e/0xa0
    [ 2767.389053]  [<ffffffff8150b81d>] scsi_unjam_host+0x10d/0x1f0
    [ 2767.389055]  [<ffffffff8150ba65>] scsi_error_handler+0x165/0x1d0
    [ 2767.389057]  [<ffffffff8150b900>] ? scsi_unjam_host+0x1f0/0x1f0
    [ 2767.389060]  [<ffffffff81093079>] kthread+0xc9/0xe0
    [ 2767.389061]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0
    [ 2767.389064]  [<ffffffff817875bc>] ret_from_fork+0x7c/0xb0
    [ 2767.389066]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0
    [ 2767.389067] INFO: task usb-storage:604 blocked for more than 120 seconds.
    [ 2767.389068]       Tainted: PF       W  O 3.14.24-031424-generic #201411141736
    [ 2767.389069] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    [ 2767.389070] usb-storage     D ffffffff81811ae0     0   604      2 0x00000000
    [ 2767.389072]  ffff88041cb55af8 0000000000000046 ffff88041cb55af8 ffff88041cb55fd8
    [ 2767.389073]  0000000000014540 0000000000014540 ffffffff81c144a0 ffff88041cb0a7c0
    [ 2767.389075]  0000000100000000 ffff880422b9d808 7fffffffffffffff 7fffffffffffffff
    [ 2767.389077] Call Trace:
    [ 2767.389079]  [<ffffffff8177a739>] schedule+0x29/0x70
    [ 2767.389081]  [<ffffffff817799e5>] schedule_timeout+0x1e5/0x250
    [ 2767.389085]  [<ffffffff8156bd58>] ? usb_hcd_submit_urb+0x88/0x1b0
    [ 2767.389086]  [<ffffffff8177b9d7>] wait_for_completion+0xa7/0x160
    [ 2767.389088]  [<ffffffff8156cece>] ? usb_alloc_urb+0x1e/0x50
    [ 2767.389092]  [<ffffffff810a4da0>] ? try_to_wake_up+0x210/0x210
    [ 2767.389093]  [<ffffffff8156f14a>] usb_sg_wait+0x13a/0x1f0
    [ 2767.389098]  [<ffffffffa019f531>] usb_stor_bulk_transfer_sglist.part.5+0x51/0xc0 [usb_storage]
    [ 2767.389102]  [<ffffffffa019f637>] usb_stor_bulk_transfer_sglist+0x97/0xa0 [usb_storage]
    [ 2767.389106]  [<ffffffffa019f66e>] usb_stor_bulk_srb+0x2e/0x50 [usb_storage]
    [ 2767.389110]  [<ffffffffa019f7d7>] usb_stor_Bulk_transport+0x147/0x3f0 [usb_storage]
    [ 2767.389112]  [<ffffffff817799e5>] ? schedule_timeout+0x1e5/0x250
    [ 2767.389116]  [<ffffffffa01a006e>] usb_stor_invoke_transport+0x3e/0x570 [usb_storage]
    [ 2767.389118]  [<ffffffff8177b1bd>] ? wait_for_completion_interruptible+0xcd/0x1c0
    [ 2767.389122]  [<ffffffffa019ee5e>] usb_stor_transparent_scsi_command+0xe/0x10 [usb_storage]
    [ 2767.389126]  [<ffffffffa01a172a>] usb_stor_control_thread+0x1ba/0x310 [usb_storage]
    [ 2767.389131]  [<ffffffffa01a1570>] ? fill_inquiry_response+0x20/0x20 [usb_storage]
    [ 2767.389132]  [<ffffffff81093079>] kthread+0xc9/0xe0
    [ 2767.389134]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0
    [ 2767.389136]  [<ffffffff817875bc>] ret_from_fork+0x7c/0xb0
    [ 2767.389137]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0
    [ 2887.525506] INFO: task scsi_eh_10:602 blocked for more than 120 seconds.
    [ 2887.525515]       Tainted: PF       W  O 3.14.24-031424-generic #201411141736
    [ 2887.525517] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    [ 2887.525521] scsi_eh_10      D ffffffff81811ae0     0   602      2 0x00000000
    [ 2887.525528]  ffff88041cb51c78 0000000000000046 0000000000000000 ffff88041cb51fd8
    [ 2887.525548]  0000000000014540 0000000000014540 ffff880428e693e0 ffff88041cb093e0
    [ 2887.525550]  000000000000000e ffff880422b9d6f0 ffff880422b9d6f4 00000000ffffffff
    [ 2887.525552] Call Trace:
    [ 2887.525558]  [<ffffffff8177a739>] schedule+0x29/0x70
    [ 2887.525560]  [<ffffffff8177aa5e>] schedule_preempt_disabled+0xe/0x10
    [ 2887.525562]  [<ffffffff8177c894>] __mutex_lock_slowpath+0x114/0x1b0
    [ 2887.525564]  [<ffffffff8177c953>] mutex_lock+0x23/0x37
    [ 2887.525583]  [<ffffffffa019e9bb>] device_reset+0x2b/0x60 [usb_storage]
    [ 2887.525586]  [<ffffffff815077ee>] scsi_try_bus_device_reset+0x2e/0x60
    [ 2887.525588]  [<ffffffff8150a37f>] scsi_eh_bus_device_reset+0xdf/0x270
    [ 2887.525590]  [<ffffffff8150a663>] ? scsi_eh_stu+0x153/0x280
    [ 2887.525592]  [<ffffffff8150a7de>] scsi_eh_ready_devs+0x4e/0xa0
    [ 2887.525594]  [<ffffffff8150b81d>] scsi_unjam_host+0x10d/0x1f0
    [ 2887.525596]  [<ffffffff8150ba65>] scsi_error_handler+0x165/0x1d0
    [ 2887.525598]  [<ffffffff8150b900>] ? scsi_unjam_host+0x1f0/0x1f0
    [ 2887.525602]  [<ffffffff81093079>] kthread+0xc9/0xe0
    [ 2887.525604]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0
    [ 2887.525606]  [<ffffffff817875bc>] ret_from_fork+0x7c/0xb0
    [ 2887.525608]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0
    [ 2887.525610] INFO: task usb-storage:604 blocked for more than 120 seconds.
    [ 2887.525611]       Tainted: PF       W  O 3.14.24-031424-generic #201411141736
    [ 2887.525612] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    [ 2887.525613] usb-storage     D ffffffff81811ae0     0   604      2 0x00000000
    [ 2887.525615]  ffff88041cb55af8 0000000000000046 ffff88041cb55af8 ffff88041cb55fd8
    [ 2887.525617]  0000000000014540 0000000000014540 ffffffff81c144a0 ffff88041cb0a7c0
    [ 2887.525619]  0000000100000000 ffff880422b9d808 7fffffffffffffff 7fffffffffffffff
    [ 2887.525621] Call Trace:
    [ 2887.525622]  [<ffffffff8177a739>] schedule+0x29/0x70
    [ 2887.525626]  [<ffffffff817799e5>] schedule_timeout+0x1e5/0x250
    [ 2887.525629]  [<ffffffff8156bd58>] ? usb_hcd_submit_urb+0x88/0x1b0
    [ 2887.525631]  [<ffffffff8177b9d7>] wait_for_completion+0xa7/0x160
    [ 2887.525633]  [<ffffffff8156cece>] ? usb_alloc_urb+0x1e/0x50
    [ 2887.525636]  [<ffffffff810a4da0>] ? try_to_wake_up+0x210/0x210
    [ 2887.525638]  [<ffffffff8156f14a>] usb_sg_wait+0x13a/0x1f0
    [ 2887.525643]  [<ffffffffa019f531>] usb_stor_bulk_transfer_sglist.part.5+0x51/0xc0 [usb_storage]
    [ 2887.525648]  [<ffffffffa019f637>] usb_stor_bulk_transfer_sglist+0x97/0xa0 [usb_storage]
    [ 2887.525652]  [<ffffffffa019f66e>] usb_stor_bulk_srb+0x2e/0x50 [usb_storage]
    [ 2887.525656]  [<ffffffffa019f7d7>] usb_stor_Bulk_transport+0x147/0x3f0 [usb_storage]
    [ 2887.525658]  [<ffffffff817799e5>] ? schedule_timeout+0x1e5/0x250
    [ 2887.525663]  [<ffffffffa01a006e>] usb_stor_invoke_transport+0x3e/0x570 [usb_storage]
    [ 2887.525665]  [<ffffffff8177b1bd>] ? wait_for_completion_interruptible+0xcd/0x1c0
    [ 2887.525669]  [<ffffffffa019ee5e>] usb_stor_transparent_scsi_command+0xe/0x10 [usb_storage]
    [ 2887.525674]  [<ffffffffa01a172a>] usb_stor_control_thread+0x1ba/0x310 [usb_storage]
    [ 2887.525678]  [<ffffffffa01a1570>] ? fill_inquiry_response+0x20/0x20 [usb_storage]
    [ 2887.525680]  [<ffffffff81093079>] kthread+0xc9/0xe0
    [ 2887.525682]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0
    [ 2887.525684]  [<ffffffff817875bc>] ret_from_fork+0x7c/0xb0
    [ 2887.525685]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0
    [ 2887.525716] INFO: task pool:14006 blocked for more than 120 seconds.
    [ 2887.525717]       Tainted: PF       W  O 3.14.24-031424-generic #201411141736
    [ 2887.525718] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    [ 2887.525719] pool            D ffffffff81811ae0     0 14006  10901 0x00000000
    [ 2887.525720]  ffff880169c3d778 0000000000000082 0000000000000000 ffff880169c3dfd8
    [ 2887.525722]  0000000000014540 0000000000014540 ffff880428e6cf80 ffff880054a11dd0
    [ 2887.525724]  ffff880169c3d778 ffff88043f3d4e20 ffff880054a11dd0 ffffffff81162050
    [ 2887.525726] Call Trace:
    [ 2887.525730]  [<ffffffff81162050>] ? __lock_page+0x70/0x70
    [ 2887.525731]  [<ffffffff8177a739>] schedule+0x29/0x70
    [ 2887.525733]  [<ffffffff8177a80f>] io_schedule+0x8f/0xd0
    [ 2887.525735]  [<ffffffff8116205e>] sleep_on_page+0xe/0x20
    [ 2887.525737]  [<ffffffff8177aed2>] __wait_on_bit+0x62/0x90
    [ 2887.525739]  [<ffffffff811621c0>] wait_on_page_bit+0x80/0x90
    [ 2887.525742]  [<ffffffff810b74d0>] ? wake_atomic_t_function+0x40/0x40
    [ 2887.525758]  [<ffffffffa02c008a>] read_extent_buffer_pages+0x2da/0x310 [btrfs]
    [ 2887.525760]  [<ffffffff81163064>] ? add_to_page_cache_lru+0x34/0x50
    [ 2887.525770]  [<ffffffffa02948d0>] ? verify_parent_transid+0x170/0x170 [btrfs]
    [ 2887.525779]  [<ffffffffa0296956>] btree_read_extent_buffer_pages.constprop.126+0xb6/0x120 [btrfs]
    [ 2887.525789]  [<ffffffffa02982b3>] read_tree_block+0x43/0x70 [btrfs]
    [ 2887.525797]  [<ffffffffa0279160>] read_block_for_search.isra.41+0x150/0x1d0 [btrfs]
    [ 2887.525804]  [<ffffffffa027b484>] btrfs_search_slot+0x304/0x830 [btrfs]
    [ 2887.525813]  [<ffffffffa02937af>] btrfs_lookup_inode+0x2f/0xa0 [btrfs]
    [ 2887.525824]  [<ffffffffa02a3a3c>] btrfs_read_locked_inode+0x7c/0x610 [btrfs]
    [ 2887.525827]  [<ffffffff811f0c6b>] ? inode_sb_list_add+0x5b/0x70
    [ 2887.525829]  [<ffffffff811f25d6>] ? iget5_locked+0x1d6/0x200
    [ 2887.525838]  [<ffffffffa02a1380>] ? btrfs_readpage+0x30/0x30 [btrfs]
    [ 2887.525848]  [<ffffffffa02aaa68>] btrfs_iget+0x78/0xf0 [btrfs]
    [ 2887.525858]  [<ffffffffa02ab14b>] btrfs_lookup_dentry+0x24b/0x280 [btrfs]
    [ 2887.525860]  [<ffffffff811ef9da>] ? __d_alloc+0x14a/0x180
    [ 2887.525869]  [<ffffffffa02ab196>] btrfs_lookup+0x16/0x40 [btrfs]
    [ 2887.525871]  [<ffffffff811e15ad>] lookup_real+0x1d/0x60
    [ 2887.525873]  [<ffffffff811e1bd8>] __lookup_hash+0x38/0x50
    [ 2887.525876]  [<ffffffff81769acc>] lookup_slow+0x45/0xab
    [ 2887.525878]  [<ffffffff811e44f0>] path_lookupat+0x6e0/0x710
    [ 2887.525880]  [<ffffffff811e2de0>] ? getname_flags.part.18+0x30/0x140
    [ 2887.525881]  [<ffffffff811e2de0>] ? getname_flags.part.18+0x30/0x140
    [ 2887.525884]  [<ffffffff811e4554>] filename_lookup+0x34/0xc0
    [ 2887.525885]  [<ffffffff811e2f56>] ? getname_flags+0x66/0x80
    [ 2887.525888]  [<ffffffff811e7ed9>] user_path_at_empty+0x59/0xa0
    [ 2887.525890]  [<ffffffff811e2d86>] ? final_putname+0x26/0x50
    [ 2887.525891]  [<ffffffff811e3059>] ? putname+0x29/0x40
    [ 2887.525893]  [<ffffffff811e7ee3>] ? user_path_at_empty+0x63/0xa0
    [ 2887.525895]  [<ffffffff811e7f31>] user_path_at+0x11/0x20
    [ 2887.525898]  [<ffffffff811dc911>] vfs_fstatat+0x51/0xb0
    [ 2887.525900]  [<ffffffff811dc9be>] vfs_lstat+0x1e/0x20
    [ 2887.525903]  [<ffffffff811dc9d5>] SYSC_newlstat+0x15/0x30
    [ 2887.525904]  [<ffffffff811dcc2b>] ? SyS_readlinkat+0x4b/0x120
    [ 2887.525906]  [<ffffffff811dcbbe>] SyS_newlstat+0xe/0x10
    [ 2887.525908]  [<ffffffff8178766d>] system_call_fastpath+0x1a/0x1f
    [ 3007.661983] INFO: task scsi_eh_10:602 blocked for more than 120 seconds.
    [ 3007.661987]       Tainted: PF       W  O 3.14.24-031424-generic #201411141736
    [ 3007.661988] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    [ 3007.661990] scsi_eh_10      D ffffffff81811ae0     0   602      2 0x00000000
    [ 3007.661993]  ffff88041cb51c78 0000000000000046 0000000000000000 ffff88041cb51fd8
    [ 3007.661996]  0000000000014540 0000000000014540 ffff880428e693e0 ffff88041cb093e0
    [ 3007.661998]  000000000000000e ffff880422b9d6f0 ffff880422b9d6f4 00000000ffffffff
    [ 3007.662000] Call Trace:
    [ 3007.662006]  [<ffffffff8177a739>] schedule+0x29/0x70
    [ 3007.662008]  [<ffffffff8177aa5e>] schedule_preempt_disabled+0xe/0x10
    [ 3007.662010]  [<ffffffff8177c894>] __mutex_lock_slowpath+0x114/0x1b0
    [ 3007.662012]  [<ffffffff8177c953>] mutex_lock+0x23/0x37
    [ 3007.662031]  [<ffffffffa019e9bb>] device_reset+0x2b/0x60 [usb_storage]
    [ 3007.662034]  [<ffffffff815077ee>] scsi_try_bus_device_reset+0x2e/0x60
    [ 3007.662036]  [<ffffffff8150a37f>] scsi_eh_bus_device_reset+0xdf/0x270
    [ 3007.662038]  [<ffffffff8150a663>] ? scsi_eh_stu+0x153/0x280
    [ 3007.662040]  [<ffffffff8150a7de>] scsi_eh_ready_devs+0x4e/0xa0
    [ 3007.662042]  [<ffffffff8150b81d>] scsi_unjam_host+0x10d/0x1f0
    [ 3007.662044]  [<ffffffff8150ba65>] scsi_error_handler+0x165/0x1d0
    [ 3007.662046]  [<ffffffff8150b900>] ? scsi_unjam_host+0x1f0/0x1f0
    [ 3007.662049]  [<ffffffff81093079>] kthread+0xc9/0xe0
    [ 3007.662051]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0
    [ 3007.662054]  [<ffffffff817875bc>] ret_from_fork+0x7c/0xb0
    [ 3007.662056]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0
    [ 3007.662058] INFO: task usb-storage:604 blocked for more than 120 seconds.
    [ 3007.662059]       Tainted: PF       W  O 3.14.24-031424-generic #201411141736
    [ 3007.662060] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    [ 3007.662061] usb-storage     D ffffffff81811ae0     0   604      2 0x00000000
    [ 3007.662063]  ffff88041cb55af8 0000000000000046 ffff88041cb55af8 ffff88041cb55fd8
    [ 3007.662065]  0000000000014540 0000000000014540 ffffffff81c144a0 ffff88041cb0a7c0
    [ 3007.662067]  0000000100000000 ffff880422b9d808 7fffffffffffffff 7fffffffffffffff
    [ 3007.662068] Call Trace:
    [ 3007.662070]  [<ffffffff8177a739>] schedule+0x29/0x70
    [ 3007.662074]  [<ffffffff817799e5>] schedule_timeout+0x1e5/0x250
    [ 3007.662077]  [<ffffffff8156bd58>] ? usb_hcd_submit_urb+0x88/0x1b0
    [ 3007.662079]  [<ffffffff8177b9d7>] wait_for_completion+0xa7/0x160
    [ 3007.662081]  [<ffffffff8156cece>] ? usb_alloc_urb+0x1e/0x50
    [ 3007.662084]  [<ffffffff810a4da0>] ? try_to_wake_up+0x210/0x210
    [ 3007.662086]  [<ffffffff8156f14a>] usb_sg_wait+0x13a/0x1f0
    [ 3007.662091]  [<ffffffffa019f531>] usb_stor_bulk_transfer_sglist.part.5+0x51/0xc0 [usb_storage]
    [ 3007.662096]  [<ffffffffa019f637>] usb_stor_bulk_transfer_sglist+0x97/0xa0 [usb_storage]
    [ 3007.662100]  [<ffffffffa019f66e>] usb_stor_bulk_srb+0x2e/0x50 [usb_storage]
    [ 3007.662104]  [<ffffffffa019f7d7>] usb_stor_Bulk_transport+0x147/0x3f0 [usb_storage]
    [ 3007.662107]  [<ffffffff817799e5>] ? schedule_timeout+0x1e5/0x250
    [ 3007.662111]  [<ffffffffa01a006e>] usb_stor_invoke_transport+0x3e/0x570 [usb_storage]
    [ 3007.662113]  [<ffffffff8177b1bd>] ? wait_for_completion_interruptible+0xcd/0x1c0
    [ 3007.662118]  [<ffffffffa019ee5e>] usb_stor_transparent_scsi_command+0xe/0x10 [usb_storage]
    [ 3007.662123]  [<ffffffffa01a172a>] usb_stor_control_thread+0x1ba/0x310 [usb_storage]
    [ 3007.662127]  [<ffffffffa01a1570>] ? fill_inquiry_response+0x20/0x20 [usb_storage]
    [ 3007.662129]  [<ffffffff81093079>] kthread+0xc9/0xe0
    [ 3007.662131]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0
    [ 3007.662133]  [<ffffffff817875bc>] ret_from_fork+0x7c/0xb0
    [ 3007.662134]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0
    [ 3007.662165] INFO: task pool:14006 blocked for more than 120 seconds.
    [ 3007.662166]       Tainted: PF       W  O 3.14.24-031424-generic #201411141736
    [ 3007.662167] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    [ 3007.662168] pool            D ffffffff81811ae0     0 14006  10901 0x00000000
    [ 3007.662170]  ffff880169c3d778 0000000000000082 0000000000000000 ffff880169c3dfd8
    [ 3007.662171]  0000000000014540 0000000000014540 ffff880428e6cf80 ffff880054a11dd0
    [ 3007.662173]  ffff880169c3d778 ffff88043f3d4e20 ffff880054a11dd0 ffffffff81162050
    [ 3007.662175] Call Trace:
    [ 3007.662179]  [<ffffffff81162050>] ? __lock_page+0x70/0x70
    [ 3007.662180]  [<ffffffff8177a739>] schedule+0x29/0x70
    [ 3007.662182]  [<ffffffff8177a80f>] io_schedule+0x8f/0xd0
    [ 3007.662184]  [<ffffffff8116205e>] sleep_on_page+0xe/0x20
    [ 3007.662185]  [<ffffffff8177aed2>] __wait_on_bit+0x62/0x90
    [ 3007.662188]  [<ffffffff811621c0>] wait_on_page_bit+0x80/0x90
    [ 3007.662190]  [<ffffffff810b74d0>] ? wake_atomic_t_function+0x40/0x40
    [ 3007.662207]  [<ffffffffa02c008a>] read_extent_buffer_pages+0x2da/0x310 [btrfs]
    [ 3007.662209]  [<ffffffff81163064>] ? add_to_page_cache_lru+0x34/0x50
    [ 3007.662219]  [<ffffffffa02948d0>] ? verify_parent_transid+0x170/0x170 [btrfs]
    [ 3007.662228]  [<ffffffffa0296956>] btree_read_extent_buffer_pages.constprop.126+0xb6/0x120 [btrfs]
    [ 3007.662238]  [<ffffffffa02982b3>] read_tree_block+0x43/0x70 [btrfs]
    [ 3007.662246]  [<ffffffffa0279160>] read_block_for_search.isra.41+0x150/0x1d0 [btrfs]
    [ 3007.662253]  [<ffffffffa027b484>] btrfs_search_slot+0x304/0x830 [btrfs]
    [ 3007.662263]  [<ffffffffa02937af>] btrfs_lookup_inode+0x2f/0xa0 [btrfs]
    [ 3007.662273]  [<ffffffffa02a3a3c>] btrfs_read_locked_inode+0x7c/0x610 [btrfs]
    [ 3007.662276]  [<ffffffff811f0c6b>] ? inode_sb_list_add+0x5b/0x70
    [ 3007.662278]  [<ffffffff811f25d6>] ? iget5_locked+0x1d6/0x200
    [ 3007.662287]  [<ffffffffa02a1380>] ? btrfs_readpage+0x30/0x30 [btrfs]
    [ 3007.662297]  [<ffffffffa02aaa68>] btrfs_iget+0x78/0xf0 [btrfs]
    [ 3007.662307]  [<ffffffffa02ab14b>] btrfs_lookup_dentry+0x24b/0x280 [btrfs]
    [ 3007.662309]  [<ffffffff811ef9da>] ? __d_alloc+0x14a/0x180
    [ 3007.662318]  [<ffffffffa02ab196>] btrfs_lookup+0x16/0x40 [btrfs]
    [ 3007.662320]  [<ffffffff811e15ad>] lookup_real+0x1d/0x60
    [ 3007.662322]  [<ffffffff811e1bd8>] __lookup_hash+0x38/0x50
    [ 3007.662324]  [<ffffffff81769acc>] lookup_slow+0x45/0xab
    [ 3007.662326]  [<ffffffff811e44f0>] path_lookupat+0x6e0/0x710
    [ 3007.662328]  [<ffffffff811e2de0>] ? getname_flags.part.18+0x30/0x140
    [ 3007.662330]  [<ffffffff811e2de0>] ? getname_flags.part.18+0x30/0x140
    [ 3007.662332]  [<ffffffff811e4554>] filename_lookup+0x34/0xc0
    [ 3007.662334]  [<ffffffff811e2f56>] ? getname_flags+0x66/0x80
    [ 3007.662336]  [<ffffffff811e7ed9>] user_path_at_empty+0x59/0xa0
    [ 3007.662338]  [<ffffffff811e2d86>] ? final_putname+0x26/0x50
    [ 3007.662340]  [<ffffffff811e3059>] ? putname+0x29/0x40
    [ 3007.662342]  [<ffffffff811e7ee3>] ? user_path_at_empty+0x63/0xa0
    [ 3007.662344]  [<ffffffff811e7f31>] user_path_at+0x11/0x20
    [ 3007.662347]  [<ffffffff811dc911>] vfs_fstatat+0x51/0xb0
    [ 3007.662349]  [<ffffffff811dc9be>] vfs_lstat+0x1e/0x20
    [ 3007.662352]  [<ffffffff811dc9d5>] SYSC_newlstat+0x15/0x30
    [ 3007.662353]  [<ffffffff811dcc2b>] ? SyS_readlinkat+0x4b/0x120
    [ 3007.662355]  [<ffffffff811dcbbe>] SyS_newlstat+0xe/0x10
    [ 3007.662357]  [<ffffffff8178766d>] system_call_fastpath+0x1a/0x1f
    [ 3127.765910] INFO: task scsi_eh_10:602 blocked for more than 120 seconds.
    [ 3127.765916]       Tainted: PF       W  O 3.14.24-031424-generic #201411141736
    [ 3127.765917] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    [ 3127.765919] scsi_eh_10      D ffffffff81811ae0     0   602      2 0x00000000
    [ 3127.765923]  ffff88041cb51c78 0000000000000046 0000000000000000 ffff88041cb51fd8
    [ 3127.765926]  0000000000014540 0000000000014540 ffff880428e693e0 ffff88041cb093e0
    [ 3127.765929]  000000000000000e ffff880422b9d6f0 ffff880422b9d6f4 00000000ffffffff
    [ 3127.765932] Call Trace:
    [ 3127.765938]  [<ffffffff8177a739>] schedule+0x29/0x70
    [ 3127.765941]  [<ffffffff8177aa5e>] schedule_preempt_disabled+0xe/0x10
    [ 3127.765944]  [<ffffffff8177c894>] __mutex_lock_slowpath+0x114/0x1b0
    [ 3127.765946]  [<ffffffff8177c953>] mutex_lock+0x23/0x37
    [ 3127.765968]  [<ffffffffa019e9bb>] device_reset+0x2b/0x60 [usb_storage]
    [ 3127.765972]  [<ffffffff815077ee>] scsi_try_bus_device_reset+0x2e/0x60
    [ 3127.765974]  [<ffffffff8150a37f>] scsi_eh_bus_device_reset+0xdf/0x270
    [ 3127.765977]  [<ffffffff8150a663>] ? scsi_eh_stu+0x153/0x280
    [ 3127.765979]  [<ffffffff8150a7de>] scsi_eh_ready_devs+0x4e/0xa0
    [ 3127.765982]  [<ffffffff8150b81d>] scsi_unjam_host+0x10d/0x1f0
    [ 3127.765985]  [<ffffffff8150ba65>] scsi_error_handler+0x165/0x1d0
    [ 3127.765987]  [<ffffffff8150b900>] ? scsi_unjam_host+0x1f0/0x1f0
    [ 3127.765991]  [<ffffffff81093079>] kthread+0xc9/0xe0
    [ 3127.765994]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0
    [ 3127.765997]  [<ffffffff817875bc>] ret_from_fork+0x7c/0xb0
    [ 3127.765999]  [<ffffffff81092fb0>] ? flush_kthread_worker+0xb0/0xb0

which does not occur on previous versions mentioned above.

3.17.2 still causes kernel panic with complete system crash with the same device.

A current workaround therefore is to switch to 3.12.32 where you'll definitely won't have problems with xhci (the USB driver) and probalby a lot with btrfs (tradeoff).