Ubuntu
linux package

  1. Bug #1768948
  2. Comment #0

Comment 0 for bug 1768948

Revision history for this message
dann frazier (dannf) wrote :

[Impact]
Hotplugging a SATA disk into a SAS controller may trigger a NULL pointer dereference, leading to a crash:

[ 2366.923208] Unable to handle kernel NULL pointer dereference
at virtual address 000007b8
...
[ 2368.766334] Call trace:
[ 2368.781712] [<ffffffc00065c3b0>] sas_find_dev_by_rphy+0x48/0x118
[ 2368.800394] [<ffffffc00065c4a8>] sas_target_alloc+0x28/0x98
[ 2368.817975] [<ffffffc00063e920>] scsi_alloc_target+0x248/0x308
[ 2368.835570] [<ffffffc000640080>] __scsi_add_device+0xb8/0x160
[ 2368.853034] [<ffffffc0006e52d8>] ata_scsi_scan_host+0x190/0x230
[ 2368.871614] [<ffffffc0006e54b0>] ata_scsi_hotplug+0xc8/0xe8
[ 2368.889152] [<ffffffc0000da75c>] process_one_work+0x164/0x438
[ 2368.908003] [<ffffffc0000dab74>] worker_thread+0x144/0x4b0
[ 2368.924613] [<ffffffc0000e0ffc>] kthread+0xfc/0x110

[Test Case]
Unplug a SATA disk from a SAS controller and insert a new SATA disk in its place.

[Regression Risk]
The fix is a clean cherry-pick from upstream that is tagged for stable. No subsequent patches in linux-next have a "Fixes:" marker referencing this patch, suggesting no regressions have been found since its introduction.