Comment 0 for bug 1743859

Version Signature
Ubuntu 4.4.0-109.132-generic 4.4.98

Attached is source code for sending a scsi command block to a sg device. When this is executed it causes a a seg fault with the stack dump that can been seen in the dmesg logs(see Below). The code worked until 4.4.0-98. It also continues to work on newer versions of ubuntu, such as Ubuntu 17.10 with the most up to date kernel 4.13.0.25. Please let me know if there is anything else information wise I can do help clarify this error. I have been able to replicate this on multiple hardware scenarios so I hope that the attached source code should be enough for you to do the same.

[ 107.963701] Call Trace:
[ 107.963715] [<ffffffff813fbb03>] dump_stack+0x63/0x90
[ 107.963727] [<ffffffff81081e52>] warn_slowpath_common+0x82/0xc0
[ 107.963729] [<ffffffff81081f9a>] warn_slowpath_null+0x1a/0x20
[ 107.963731] [<ffffffff815dcc9e>] sg_rq_end_io+0x24e/0x340
[ 107.963741] [<ffffffff8152b33e>] ? add_timer_randomness+0xde/0x100
[ 107.963745] [<ffffffff813cc592>] blk_finish_request+0x62/0xf0
[ 107.963748] [<ffffffff815c5d76>] scsi_end_request+0x106/0x1d0
[ 107.963750] [<ffffffff815c93d6>] scsi_io_completion+0x1b6/0x690
[ 107.963752] [<ffffffff815bffff>] scsi_finish_command+0xcf/0x120
[ 107.963754] [<ffffffff815c47c5>] scsi_eh_flush_done_q+0xf5/0x140
[ 107.963760] [<ffffffff815f2bc9>] ata_scsi_port_error_handler+0x599/0x770
[ 107.963763] [<ffffffff815ed5ad>] ? ata_scsi_cmd_error_handler+0x11d/0x150
[ 107.963765] [<ffffffff815f2e40>] ata_scsi_error+0xa0/0xe0
[ 107.963766] [<ffffffff815c4cfb>] scsi_error_handler+0xdb/0x8a0
[ 107.963779] [<ffffffff81840010>] ? __schedule+0x310/0x7b0
[ 107.963781] [<ffffffff815c4c20>] ? scsi_eh_get_sense+0x240/0x240
[ 107.963788] [<ffffffff810a1845>] kthread+0xe5/0x100
[ 107.963790] [<ffffffff810a1760>] ? kthread_create_on_node+0x1e0/0x1e0
[ 107.963792] [<ffffffff81844a0f>] ret_from_fork+0x3f/0x70
[ 107.963794] [<ffffffff810a1760>] ? kthread_create_on_node+0x1e0/0x1e0
[ 107.963795] ---[ end trace b723db66c786bceb ]---

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-109-generic 4.4.0-109.132
ProcVersionSignature: Ubuntu 4.4.0-109.132-generic 4.4.98
Uname: Linux 4.4.0-109-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.15
Architecture: amd64
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
CurrentDesktop: Unity
Date: Wed Jan 17 12:34:22 2018
HibernationDevice: RESUME=/dev/mapper/pc17--vg-swap_1
InstallationDate: Installed on 2018-01-17 (0 days ago)
InstallationMedia: Ubuntu-Server 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801)
IwConfig:
 lo no wireless extensions.

 ens192 no wireless extensions.
Lsusb: Error: command ['lsusb'] failed with exit code 1:
MachineType: VMware, Inc. VMware Virtual Platform
ProcFB: 0 svgadrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.4.0-109-generic root=/dev/mapper/hostname--vg-root ro
PulseList:
 Error: command ['pacmd', 'list'] failed with exit code 1: XDG_RUNTIME_DIR (/run/user/1000) is not owned by us (uid 0), but by uid 1000! (This could e g happen if you try to connect to a non-root PulseAudio as a root user, over the native protocol. Don't do that.)
 No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
 linux-restricted-modules-4.4.0-109-generic N/A
 linux-backports-modules-4.4.0-109-generic N/A
 linux-firmware 1.157.14
RfKill:

SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/14/2014
dmi.bios.vendor: Phoenix Technologies LTD
dmi.bios.version: 6.00
dmi.board.name: 440BX Desktop Reference Platform
dmi.board.vendor: Intel Corporation
dmi.board.version: None
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 1
dmi.chassis.vendor: No Enclosure
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnPhoenixTechnologiesLTD:bvr6.00:bd04/14/2014:svnVMware,Inc.:pnVMwareVirtualPlatform:pvrNone:rvnIntelCorporation:rn440BXDesktopReferencePlatform:rvrNone:cvnNoEnclosure:ct1:cvrN/A:
dmi.product.name: VMware Virtual Platform
dmi.product.version: None
dmi.sys.vendor: VMware, Inc.