Re: [PATCH v3 2/4] xfs: initialize inode security on tmpfile creation

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 04/15/2014 04:22 PM, Christoph Hellwig wrote:
> On Tue, Apr 15, 2014 at 04:04:32PM -0400, Stephen Smalley wrote:
>> Is there a reason that xfs_init_security() isn't called from the inode
>> allocation function (e.g. xfs_ialloc), as in ext4 (__ext4_new_inode
>> calls ext4_init_security and also calls ext4_init_acl)?  That would have
>> ensured that tmpfile inodes would have been labeled without requiring a
>> separate change and more generally ensures complete coverage for all inodes.
> 
> Really just code structuring - we don't like callouts to high level VFS
> functions from deep down in the guts of the filesystem.
> 
>> For SELinux, we need the tmpfile inodes to be labeled at creation time,
>> not just if linked into the namespace, since they may be shared via
>> local socket IPC or inherited across a label-changing exec and since we
>> revalidate access on transfer or use.
>>
>> Labeling based on the provided directory could be a bit random, although
>> it will work out with current policy if the provided directory
>> corresponds to existing tmpfile locations (e.g. /tmp, /var/tmp) and
>> therefore already has a label associated with temporary files.
>> Otherwise we might want some indication that it is a tmpfile passed into
>> security_inode_init_security() so that we can always select a stable
>> label irrespective of the directory.
> 
> Just check for I_LINKABLE in i_flags.

Thanks, that should allow us to handle it cleanly in the security modules!


--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux