Suppressing selinux label getxattrs on FUSE

Suppressing selinux label getxattrs on FUSE

[Han-Wen Nienhuys]

Hi there,

What is the best way to stop to SELinux from trying read ACL security
labels for (FUSE) mounts?

Background:

>From what I read, Selinux is not really working on FUSE filesystems,
however, when I run a FUSE filesystem, I see various GETXATTR calls
passing by asking for

security.capability
system.posix_acl_default
system.posix_acl_access

In the most common use case, it is the user that runs the FUSE daemon,
and the mount is only visible to him.  In this case, inspection of
security/access labels haves no sense at all. Since the calls have
overhead (each one requires a context switch, costing about 10us), I
would like to suppress them.

-- 
Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen

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Re: Suppressing selinux label getxattrs on FUSE

[Christopher J. PeBenito]

On 03/06/12 06:51, Han-Wen Nienhuys wrote:
> Hi there,
> 
> What is the best way to stop to SELinux from trying read ACL security
> labels for (FUSE) mounts?
> 
> Background:
> 
> From what I read, Selinux is not really working on FUSE filesystems,
> however, when I run a FUSE filesystem, I see various GETXATTR calls
> passing by asking for

SELinux uses the security.selinux xattr.
 
> security.capability

I'm guessing this is for fs capabilities.

> system.posix_acl_default
> system.posix_acl_access

POSIX ACL.

You'd presumably have to disable these mechanisms to eliminate this access.

-- 
Chris PeBenito
Tresys Technology, LLC
www.tresys.com | oss.tresys.com

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Re: Suppressing selinux label getxattrs on FUSE

[Han-Wen Nienhuys]

On Tue, Mar 6, 2012 at 10:07 AM, Christopher J. PeBenito
<cpebenito@tresys.com> wrote:
> On 03/06/12 06:51, Han-Wen Nienhuys wrote:
>> Hi there,
>>
>> What is the best way to stop to SELinux from trying read ACL security
>> labels for (FUSE) mounts?
>>
>> Background:
>>
>> From what I read, Selinux is not really working on FUSE filesystems,
>> however, when I run a FUSE filesystem, I see various GETXATTR calls
>> passing by asking for
>
> SELinux uses the security.selinux xattr.
>
>> security.capability
>
> I'm guessing this is for fs capabilities.
>
>> system.posix_acl_default
>> system.posix_acl_access
>
> POSIX ACL.
>
> You'd presumably have to disable these mechanisms to eliminate this access.

Would you have some pointers to background on these mechanisms?  Sorry
for the newbie-ish question.

-- 
Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen

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