lkml.org 
[lkml]   [2012]   [Jan]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2.6.32-stable] block: fail SCSI passthrough ioctls on partition devices
On Fri, Jan 27, 2012 at 05:56:54PM +0100, Paolo Bonzini wrote:
> commit 0bfc96cb77224736dfa35c3c555d37b3646ef35e upstream.
>
> Linux allows executing the SG_IO ioctl on a partition or LVM volume, and
> will pass the command to the underlying block device. This is
> well-known, but it is also a large security problem when (via Unix
> permissions, ACLs, SELinux or a combination thereof) a program or user
> needs to be granted access only to part of the disk.
>
> This patch lets partitions forward a small set of harmless ioctls;
> others are logged with printk so that we can see which ioctls are
> actually sent. In my tests only CDROM_GET_CAPABILITY actually occurred.
> Of course it was being sent to a (partition on a) hard disk, so it would
> have failed with ENOTTY and the patch isn't changing anything in
> practice. Still, I'm treating it specially to avoid spamming the logs.
>
> In principle, this restriction should include programs running with
> CAP_SYS_RAWIO. If for example I let a program access /dev/sda2 and
> /dev/sdb, it still should not be able to read/write outside the
> boundaries of /dev/sda2 independent of the capabilities. However, for
> now programs with CAP_SYS_RAWIO will still be allowed to send the
> ioctls. Their actions will still be logged.
>
> This patch does not affect the non-libata IDE driver. That driver
> however already tests for bd != bd->bd_contains before issuing some
> ioctl; it could be restricted further to forbid these ioctls even for
> programs running with CAP_SYS_ADMIN/CAP_SYS_RAWIO.
>
> Cc: linux-scsi@vger.kernel.org
> Cc: Jens Axboe <axboe@kernel.dk>
> Cc: James Bottomley <JBottomley@parallels.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> [ Make it also print the command name when warning - Linus ]
> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
>
> [ Changes with respect to 3.3: return -ENOTTY from scsi_verify_blk_ioctl
> and -ENOIOCTLCMD from sd_compat_ioctl. ]

Thanks, I've replaced the version in the 2.6.32-stable queue with this
one.

greg k-h


\
 
 \ /
  Last update: 2012-01-28 00:25    [W:0.056 / U:0.240 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site