[SSSD] [PATCH] SELINUX: Set permissive umask for selinux operations

Jakub Hrozek jhrozek at redhat.com
Tue Jan 27 17:11:22 UTC 2015


On Tue, Jan 27, 2015 at 11:42:27AM -0500, Roland Mainz wrote:
> 
> 
> ----- Original Message -----
> > From: "Jakub Hrozek" <jhrozek at redhat.com>
> > To: sssd-devel at lists.fedorahosted.org
> > Sent: Tuesday, January 27, 2015 5:38:57 PM
> > Subject: Re: [SSSD] [PATCH] SELINUX: Set permissive umask for selinux operations
> > 
> > On Tue, Jan 27, 2015 at 05:25:36PM +0100, Jakub Hrozek wrote:
> > > On Tue, Jan 27, 2015 at 11:07:01AM -0500, Roland Mainz wrote:
> > > > 
> > > > 
> > > > ----- Original Message -----
> > > > > From: "Roland Mainz" <rmainz at redhat.com>
> > > > > To: "Development of the System Security Services Daemon"
> > > > > <sssd-devel at lists.fedorahosted.org>
> > > > > Sent: Tuesday, January 27, 2015 4:41:28 PM
> > > > > Subject: Re: [SSSD] [PATCH] SELINUX: Set permissive umask for selinux
> > > > > operations
> > > > > 
> > > > > 
> > > > > 
> > > > > ----- Original Message -----
> > > > > > From: "Jakub Hrozek" <jhrozek at redhat.com>
> > > > > > To: sssd-devel at lists.fedorahosted.org
> > > > > > Sent: Tuesday, January 27, 2015 11:31:58 AM
> > > > > > Subject: Re: [SSSD] [PATCH] SELINUX: Set permissive umask for selinux
> > > > > > operations
> > > > > > 
> > > > > > On Tue, Jan 27, 2015 at 10:51:24AM +0100, Jakub Hrozek wrote:
> > > > > > > Alternatively, we could only set and reset the umask in the caller.
> > > > > > > That
> > > > > > > way, we would know that a short-lived selinux_child is changing
> > > > > > > umask.
> > > > > > > 
> > > > > > > That is safer, but risks that we forget next time..so at least we
> > > > > > > need
> > > > > > > to add a comment to the declaration in header.
> > > > > > 
> > > > > > Attached is an alternate patch that only touches the umask in the
> > > > > > short-lived process.
> > > > > 
> > > > > Which syscall exactly (strace dump, please) causes the original issue ?
> > > > > Maybe
> > > > > there is a way to do this without having to rely on |umask()| (using
> > > > > the
> > > > > |*at()| APIs or a later modification of the permissions) ...
> > > > 
> > > > I discussed this with jhrozek on IRC... basically libsemanage should fix
> > > > the permissions after the |mkdir()| call like the mkdir(1) code in
> > > > https://searchcode.com/codesearch/view/5481405/ line 160 ... but until
> > > > they we have to stick with the |umask()| workaround (and praying that
> > > > sssd never uses threads).
> > > 
> > > I filed:
> > > https://bugzilla.redhat.com/show_bug.cgi?id=1186422
> > > and:
> > > https://bugzilla.redhat.com/show_bug.cgi?id=1186431
> > > 
> > > against libsemanage. As discussed with Roland on IRC, I will add a URL
> > > of the bugzilla to a comment in selinux_child to make it clear that it's
> > > just a workaround for a bug, not a clean solution.
> > 
> > FYI, I'll push the attached patch. The only difference from the version
> > Michal acked is the additional comment.
> 
> Thanks for the bug reference in the patch... the patch is r=rmainz at redhat.com ...

Pushed upstream:
    * master: 8f78b6442f3176ee43aa06704a3adb9f4ac625d6
    * sssd-1-12: b8894eb53017af67224d05470d2cdd2a65070a41 



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