PING^4 aka The Jon Corbet Effect Re: [PATCH v2 00/14] Correctionsand customization of the SG_IO command whitelist (CVE-2012-4542)

[Paolo Bonzini]

And a fourth ping comes...

Jon, the next time I read "it seems likely to be picked up fairly soon"
(http://lwn.net/Articles/535075/), I'll picture the author of the patch
attempting open-heart surgery on a long-red-haired voodoo doll!

Paolo

Il 04/04/2013 20:18, Paolo Bonzini ha scritto:
> Il 22/03/2013 23:30, Paolo Bonzini ha scritto:
>> Il 20/02/2013 17:12, Paolo Bonzini ha scritto:
>>> Il 06/02/2013 16:15, Paolo Bonzini ha scritto:
>>>> This series regards the whitelist that is used for the SG_IO ioctl.  This
>>>> whitelist has three problems:
>>>>
>>>> * the bitmap of allowed commands is designed for MMC devices (roughly,
>>>>   "play/burn CDs without requiring root") but some opcodes overlap across SCSI
>>>>   device classes and have different meanings for different classes.
>>>>
>>>> * also because the bitmap of allowed commands is designed for MMC devices
>>>>   only, some commands are missing even though they are generally useful and
>>>>   not insecure.  At least not more insecure than anything else you can
>>>>   do if you have access to /dev/sdX or /dev/stX nodes.
>>>>
>>>> * the whitelist can be disabled per-process but not per-disk.  In addition,
>>>>   the required capability (CAP_SYS_RAWIO) gives access to a range of other 
>>>>   resources, enough to make it insecure.
>>>>
>>>> The series corrects these problems.  Patches 1-4 solve the first problem,
>>>> which also has an assigned CVE, by using different bitmaps for the various
>>>> device classes.  Patches 5-11 solve the second by adding more commands
>>>> to the bitmaps.  Patches 12 and 13 solve the third, and were already
>>>> posted but ignored by the maintainers despite multiple pings.
>>>>
>>>> Note: checkpatch hates the formatting of the command table.  I know about this,
>>>> and ensured that there are no errors in the rest of the code.  The current
>>>> formatting is IMHO quite handy, and roughly based on the files available
>>>> from the SCSI standard body.
>>>>
>>>> Ok for the next merge window?
>>>>
>>>> Paolo
>>>>
>>>> v1->v2: remove 2 MMC commands and 6 SBC commands (see patches 6 and 9
>>>>         for details).  Added patch 14 and added a few more scanner
>>>>         commands based on SANE (scanners are not whitelisted by default,
>>>>         also were not in v1, but this makes it possible to opt into the
>>>>         whitelist out of paranoia).  Removed C++ comments.  Removed the
>>>>         large #if 0'd list of commands that the kernel does not pass
>>>>         though.  Marked blk_set_cmd_filter_defaults as __init.
>>>
>>> Ping...
>>>
>>> Jens/James, is anyone going to pick this up for 3.9?
>>
>> Another month has passed, Ping^2...
> 
> Ping^3, any hope for 3.10?
> 
> Paolo
> 
>>
>> Paolo
>>
>>> Paolo
>>>
>>>>
>>>> Paolo Bonzini (14):
>>>>   sg_io: pass request_queue to blk_verify_command
>>>>   sg_io: reorganize list of allowed commands
>>>>   sg_io: use different default filters for each device class
>>>>   sg_io: resolve conflicts between commands assigned to multiple
>>>>     classes (CVE-2012-4542)
>>>>   sg_io: whitelist a few more commands for rare & obsolete device types
>>>>   sg_io: whitelist another command for multimedia devices
>>>>   sg_io: whitelist a few more commands for media changers
>>>>   sg_io: whitelist a few more commands for tapes
>>>>   sg_io: whitelist a few more commands for disks
>>>>   sg_io: whitelist a few obsolete commands
>>>>   sg_io: mark blk_set_cmd_filter_defaults as __init
>>>>   sg_io: remove remnants of sysfs SG_IO filters
>>>>   sg_io: introduce unpriv_sgio queue flag
>>>>   sg_io: use unpriv_sgio to disable whitelisting for scanners
>>>>
>>>>  Documentation/block/queue-sysfs.txt |    8 +
>>>>  block/blk-sysfs.c                   |   33 +++
>>>>  block/bsg.c                         |    2 +-
>>>>  block/scsi_ioctl.c                  |  369 ++++++++++++++++++++++++++---------
>>>>  drivers/scsi/scsi_scan.c            |   14 ++-
>>>>  drivers/scsi/sg.c                   |    6 +-
>>>>  include/linux/blkdev.h              |    8 +-
>>>>  include/linux/genhd.h               |    9 -
>>>>  include/scsi/scsi.h                 |    3 +
>>>>  9 files changed, 344 insertions(+), 108 deletions(-)
>>>>
>>>
>>
> 

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