Thread: BUG #1670: pg_dump fails on CentOS 4

The following bug has been logged online:

Bug reference:      1670
Logged by:          Josh
Email address:      josh@globalherald.net
PostgreSQL version: 8.0.2, 8.0.3
Operating system:   CentOS 4
Description:        pg_dump fails on CentOS 4
Details:

pg_dump, as packaged in postgresql-8.0.3-1PGDG.i686.rpm, fails with no
output whatsoever when run from a terminal window:

[josh@localhost ~]$ pg_dump -U username database > backup.sql
[josh@localhost ~]$

However, when run from within pgadmin3, it runs as it should.

When I download the source to 8.0.3 and compile it from scratch, the freshly
compiled pg_dump works as it should from any source (PGAdmin3, command line)

"Josh" <josh@globalherald.net> writes:
> The following bug has been logged online:
> pg_dump, as packaged in postgresql-8.0.3-1PGDG.i686.rpm, fails with no
> output whatsoever when run from a terminal window:

> [josh@localhost ~]$ pg_dump -U username database > backup.sql

Try turning off SELinux enforcement, or better update the selinux
policy package and do a restorecon on all of /usr/bin.  The earlier
releases of selinux-policy-targeted prevent pg_dump from writing on
/dev/tty :-( ... which makes it a bit hard to emit error messages...

            regards, tom lane

josh@bitbuckets.com writes:
> Does this policy also apply to binaries compiled on the local machine?
> When I compiled PG803 from source, then copied pg_dump to /usr/bin as
> root, pg_dump worked fine.

AFAIK the policy is driven off the pathname of the executable --- so it
doesn't matter who compiled pg_dump, only where it is installed.
Also, there is a notion of "labeling" which is basically an extension
of file access bits (see "ls -Z").  What restorecon basically does is
update the labeling to be what the current policy says it should be.
So I'd expect your homebuilt pg_dump to start failing also if you
restorecon it with the current policy.

On my FC3 machine, with a pretty up-to-date policy, I see

$ cd /usr/bin
$ ls -Z postgres postmaster pg_dump
-rwxr-xr-x  root     root     system_u:object_r:bin_t          pg_dump*
-rwxr-xr-x  root     root     system_u:object_r:postgresql_exec_t postgres*
lrwxrwxrwx  root     root     system_u:object_r:bin_t          postmaster

The /dev/tty restriction is associated with the postgresql_exec_t
labeling.  I believe that the policy bug was essentially due to someone
not understanding that pg_dump isn't used as a daemon ...

[ObDisclaimer: I'm not a SELinux guru and have probably missed lots of
fine points.]

            regards, tom lane

Tom,

> Try turning off SELinux enforcement, or better update the selinux
> policy package and do a restorecon on all of /usr/bin.  The earlier

I'll definitely give this a try.

Does this policy also apply to binaries compiled on the local machine?
When I compiled PG803 from source, then copied pg_dump to /usr/bin as
root, pg_dump worked fine.

Thanks for the help!
--Josh