libsndfile 1.0.17 unable to write file in FC6. SELinux???

[stan]

Hi,

I am developing an app that writes sound files.  When I link it with
the FC6 libsndfile libraries, either statically or dynamically, it gives
me an error that it cannot open the file.  It is able to create the
file, because I see it there empty.  When I compile the libsndfile
1.0.17 source myself, and link statically to it, the application is
able to create and write the file (i.e. it works as it is supposed to).

Unfortunately the debugging information has been stripped from the FC6
libraries so I can't trace the problem.  The only thing I can think of
is that this is some sort of SELinux issue.  I am running this as a
user with the default permissions (permissive if I recall).  From what
I have read this should mean there are no issues with SELinux at all
under targeted policy.

Any suggestions as to why this is happening, and possible fixes?

Thanks,
Stan

[Tony Nelson]

At 10:44 AM -0700 4/22/07, stan wrote:
> Hi,
>
> I am developing an app that writes sound files.  When I link it with
> the FC6 libsndfile libraries, either statically or dynamically, it gives
> me an error that it cannot open the file.  It is able to create the
> file, because I see it there empty.  When I compile the libsndfile
> 1.0.17 source myself, and link statically to it, the application is
> able to create and write the file (i.e. it works as it is supposed to).
>
> Unfortunately the debugging information has been stripped from the FC6
> libraries so I can't trace the problem.

Enable the -debuginfo repos and install the libsndfile-debuginfo package:

# yum --enablerepo extras-debuginfo install libsndfile-debuginfo
> The only thing I can think of
> is that this is some sort of SELinux issue.  I am running this as a
> user with the default permissions (permissive if I recall).  From what
> I have read this should mean there are no issues with SELinux at all
> under targeted policy.
>
> Any suggestions as to why this is happening, and possible fixes?

Find out if selinux is in permissive mode:

# sestatus

Find out if selinux is denying access by looking in the log, either
/ver/log/messages, or if audit is installed /var/log/audit/audit.log.

libsndfile 1.0.17 unable to write file in FC6. SELinux??? Solved, not SELinux, package configuration.

[stan]

On Sun, 22 Apr 2007 15:37:20 -0400
Tony Nelson  wrote:
> At 10:44 AM -0700 4/22/07, stan wrote:
> > Hi,
> >
> > I am developing an app that writes sound files.  When I link it with
> > the FC6 libsndfile libraries, either statically or dynamically, it
> > gives me an error that it cannot open the file.  It is able to
> > create the file, because I see it there empty.  When I compile the
> > libsndfile 1.0.17 source myself, and link statically to it, the
> > application is able to create and write the file (i.e. it works as
> > it is supposed to).
> >
> > Unfortunately the debugging information has been stripped from the
> > FC6 libraries so I can't trace the problem.
>
> Enable the -debuginfo repos and install the libsndfile-debuginfo
> package:
> # yum --enablerepo extras-debuginfo install libsndfile-debuginfo

This worked great.  They are optimized, so the source is a little
disjointed.  And mystery solved.  At configuration, libsndfile checks
for flac.  It it isn't there, it puts in a stub that returns an error.
Libsndfile just returns a null pointer in this case so there is no
indication of what is wrong. The maintainer of the
libsndfile package doesn't have flac installed on the machine they
compile on. That's why it worked when I compiled on my machine where
flac is installed.
> > The only thing I can think of
> > is that this is some sort of SELinux issue.  I am running this as a
> > user with the default permissions (permissive if I recall).  From
> > what I have read this should mean there are no issues with SELinux
> > at all under targeted policy.
> >
> > Any suggestions as to why this is happening, and possible fixes?
>
> Find out if selinux is in permissive mode:
> # sestatus

# /usr/sbin/sestatus
SELinux status:                 enabled
SELinuxfs mount:                /selinux
Current mode:                   permissive
Mode from config file:          permissive
Policy version:                 21
Policy from config file:        targeted
> Find out if selinux is denying access by looking in the log, either
> /ver/log/messages, or if audit is installed /var/log/audit/audit.log.

This proved informative.  SELinux wasn't denying the request.  But I
noticed that a remote attacker was using compromised machines from all
over the world to try to log into sshd on my machine.  I disabled it.

Thanks for your help Tony.

Stan

libsndfile 1.0.17 unable to write file in FC6. SELinux??? Solved, not SELinux, package configuration.

[Michael Schwendt]

On 23/04/07, stan wrote:
> And mystery solved.  At configuration, libsndfile checks
> for flac.  It it isn't there, it puts in a stub that returns an error.
> Libsndfile just returns a null pointer in this case so there is no
> indication of what is wrong. The maintainer of the
> libsndfile package doesn't have flac installed on the machine they
> compile on. That's why it worked when I compiled on my machine where
> flac is installed.

Then that is a missing "BuildRequires: flac-devel" in the Fedora
Extras 6 package. Can you please submit a bug report about your
problem at http://bugzilla.redhat.com