c6c1f325adc8a8e0cd06c6ad0ca232a6880a1783: exhibits this bug:

Sep  8 22:18:29 box kernel: [ 1940.144024] BUG: soft lockup - CPU#0 stuck for 22s! [md3_raid1:172]
Sep  8 22:18:29 box kernel: [ 1940.144024] Modules linked in: xt_multiport iptable_filter ip_tables x_tables gpio_ich snd_hda_codec_realtek coretemp snd_hda_intel snd_hda_codec serio_raw snd_hwdep pl2303 usblp usbserial lpc_ich snd_pcm snd_page_alloc snd_timer i915 drm_kms_helper snd drm soundcore i2c_algo_bit video mac_hid parport_pc ppdev lp parport dm_snapshot raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor ahci psmouse r8169 sata_via libahci raid6_pq mii raid1 raid0 multipath linear
Sep  8 22:18:29 box kernel: [ 1940.144024] CPU: 0 PID: 172 Comm: md3_raid1 Not tainted 3.13.0-031300rc1-generic #201409081748
Sep  8 22:18:29 box kernel: [ 1940.144024] Hardware name:                  /D945GSEJT, BIOS JT94510H.86A.0045.2010.0519.1750 05/19/2010
Sep  8 22:18:29 box kernel: [ 1940.144024] task: f6888cf0 ti: f6b68000 task.ti: f6b68000
Sep  8 22:18:29 box kernel: [ 1940.144024] EIP: 0060:[<c12ff0b2>] EFLAGS: 00000297 CPU: 0
Sep  8 22:18:29 box kernel: [ 1940.144024] EIP is at memcmp+0x32/0x60
Sep  8 22:18:29 box kernel: [ 1940.144024] EAX: ecb27000 EBX: 0000007e ECX: 00000962 EDX: ec8de000
Sep  8 22:18:29 box kernel: [ 1940.144024] ESI: 0000007e EDI: 00000fff EBP: f6b69e9c ESP: f6b69e8c
Sep  8 22:18:29 box kernel: [ 1940.144024]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Sep  8 22:18:29 box kernel: [ 1940.144024] CR0: 8005003b CR2: bfc95ef4 CR3: 01ae4000 CR4: 000007f0
Sep  8 22:18:29 box kernel: [ 1940.144024] Stack:
Sep  8 22:18:29 box kernel: [ 1940.144024]  00000000 00000006 00001000 00000048 f6b69ee0 f845d3b3 ec8de000 00000001
Sep  8 22:18:29 box kernel: [ 1940.144024]  0000000f f6847800 00000007 ecb9e800 f69d2f80 f50da4e0 0000000c ecb9ea00
Sep  8 22:18:29 box kernel: [ 1940.144024]  0000001c ecd53300 00000002 ecd53300 f6847800 f6b69f00 f845d667 f6847800
Sep  8 22:18:29 box kernel: [ 1940.144024] Call Trace:
Sep  8 22:18:29 box kernel: [ 1940.144024]  [<f845d3b3>] process_checks+0x173/0x300 [raid1]
Sep  8 22:18:29 box kernel: [ 1940.144024]  [<f845d667>] sync_request_write+0x127/0x160 [raid1]
Sep  8 22:18:29 box kernel: [ 1940.144024]  [<f845f5d2>] raid1d+0x102/0x140 [raid1]
Sep  8 22:18:29 box kernel: [ 1940.144024]  [<c151bf54>] md_thread+0xe4/0x110
Sep  8 22:18:29 box kernel: [ 1940.144024]  [<c1095010>] ? __wake_up_sync+0x20/0x20
Sep  8 22:18:29 box kernel: [ 1940.144024]  [<c151be70>] ? md_rdev_init+0x100/0x100
Sep  8 22:18:29 box kernel: [ 1940.144024]  [<c107801b>] kthread+0x9b/0xb0
Sep  8 22:18:29 box kernel: [ 1940.144024]  [<c1684077>] ret_from_kernel_thread+0x1b/0x28
Sep  8 22:18:29 box kernel: [ 1940.144024]  [<c1077f80>] ? flush_kthread_worker+0x90/0x90
Sep  8 22:18:29 box kernel: [ 1940.144024] Code: ec 04 85 c9 c7 45 f0 00 00 00 00 74 29 0f b6 30 0f b6 1a 29 de 89 75 f0 75 1c 8d 79 ff 31 c9 eb 11 0f b6 74 08 01 0f b6 5c 0a 01 <83> c1 01 29 de 75 0f 39 f9 75 eb 8b 45 f0 83 c4 04 5b 5e 5f 5d
Sep  8 22:38:36 box mdadm[1615]: Rebuild21 event detected on md device /dev/md/03
Sep  8 22:41:05 box kernel: [ 3296.144025] BUG: soft lockup - CPU#0 stuck for 22s! [md3_raid1:172]
Sep  8 22:41:05 box kernel: [ 3296.144025] Modules linked in: xt_multiport iptable_filter ip_tables x_tables gpio_ich snd_hda_codec_realtek coretemp snd_hda_intel snd_hda_codec serio_raw snd_hwdep pl2303 usblp usbserial lpc_ich snd_pcm snd_page_alloc snd_timer i915 drm_kms_helper snd drm soundcore i2c_algo_bit video mac_hid parport_pc ppdev lp parport dm_snapshot raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor ahci psmouse r8169 sata_via libahci raid6_pq mii raid1 raid0 multipath linear
Sep  8 22:41:05 box kernel: [ 3296.144025] CPU: 0 PID: 172 Comm: md3_raid1 Not tainted 3.13.0-031300rc1-generic #201409081748
Sep  8 22:41:05 box kernel: [ 3296.144025] Hardware name:                  /D945GSEJT, BIOS JT94510H.86A.0045.2010.0519.1750 05/19/2010
Sep  8 22:41:05 box kernel: [ 3296.144025] task: f6888cf0 ti: f6b68000 task.ti: f6b68000
Sep  8 22:41:05 box kernel: [ 3296.144025] EIP: 0060:[<c12ff0bb>] EFLAGS: 00000293 CPU: 0
Sep  8 22:41:05 box kernel: [ 3296.144025] EIP is at memcmp+0x3b/0x60
Sep  8 22:41:05 box kernel: [ 3296.144025] EAX: ec884000 EBX: 000000ed ECX: 00000056 EDX: ecddf000
Sep  8 22:41:05 box kernel: [ 3296.144025] ESI: 00000000 EDI: 00000fff EBP: f6b69e9c ESP: f6b69e8c
Sep  8 22:41:05 box kernel: [ 3296.144025]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Sep  8 22:41:05 box kernel: [ 3296.144025] CR0: 8005003b CR2: b88467a4 CR3: 01ae4000 CR4: 000007f0
Sep  8 22:41:05 box kernel: [ 3296.144025] Stack:
Sep  8 22:41:05 box kernel: [ 3296.144025]  00000000 0000000b 00001000 00000084 f6b69ee0 f845d3b3 ecddf000 00000001
Sep  8 22:41:05 box kernel: [ 3296.144025]  0000000f f6847800 0000000c ec8c1400 f69d2f80 f50d5080 0000000c eccb8000
Sep  8 22:41:05 box kernel: [ 3296.144025]  0000001c ece7ed20 00000002 ece7ed20 f6847800 f6b69f00 f845d667 f6847800
Sep  8 22:41:05 box kernel: [ 3296.144025] Call Trace:
Sep  8 22:41:05 box kernel: [ 3296.144025]  [<f845d3b3>] process_checks+0x173/0x300 [raid1]
Sep  8 22:41:05 box kernel: [ 3296.144025]  [<f845d667>] sync_request_write+0x127/0x160 [raid1]
Sep  8 22:41:05 box kernel: [ 3296.144025]  [<f845f5d2>] raid1d+0x102/0x140 [raid1]
Sep  8 22:41:05 box kernel: [ 3296.144025]  [<c151bf54>] md_thread+0xe4/0x110
Sep  8 22:41:05 box kernel: [ 3296.144025]  [<c1095010>] ? __wake_up_sync+0x20/0x20
Sep  8 22:41:05 box kernel: [ 3296.144025]  [<c151be70>] ? md_rdev_init+0x100/0x100
Sep  8 22:41:05 box kernel: [ 3296.144025]  [<c107801b>] kthread+0x9b/0xb0
Sep  8 22:41:05 box kernel: [ 3296.144025]  [<c1684077>] ret_from_kernel_thread+0x1b/0x28
Sep  8 22:41:05 box kernel: [ 3296.144025]  [<c1077f80>] ? flush_kthread_worker+0x90/0x90
Sep  8 22:41:05 box kernel: [ 3296.144025] Code: 00 00 74 29 0f b6 30 0f b6 1a 29 de 89 75 f0 75 1c 8d 79 ff 31 c9 eb 11 0f b6 74 08 01 0f b6 5c 0a 01 83 c1 01 29 de 75 0f 39 f9 <75> eb 8b 45 f0 83 c4 04 5b 5e 5f 5d c3 89 75 f0 8b 45 f0 83 c4