linux-kernel - Re: named + capset = EPERM [Was: 2.6.24-rc3-mm2]

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20071129001701.GA26817@sergelap.austin.ibm.com>
Date:	Wed, 28 Nov 2007 18:17:01 -0600
From:	"Serge E. Hallyn" <serue@...ibm.com>
To:	"Serge E. Hallyn" <serue@...ibm.com>
Cc:	Casey Schaufler <casey@...aufler-ca.com>,
	Jiri Slaby <jirislaby@...il.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org,
	"Andrew G. Morgan" <morgan@...nel.org>
Subject: Re: named + capset = EPERM [Was: 2.6.24-rc3-mm2]

Quoting Serge E. Hallyn (serue@...ibm.com):
> Quoting Serge E. Hallyn (serue@...ibm.com):
> > Quoting Casey Schaufler (casey@...aufler-ca.com):
> > > 
> > > --- Jiri Slaby <jirislaby@...il.com> wrote:
> > > 
> > > > On 11/28/2007 12:41 PM, Andrew Morton wrote:
> > > > >
> > > >
> > > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.24-rc3/2.6.24-rc3-mm2/
> > > > [...]
> > > > > +capabilities-introduce-per-process-capability-bounding-set.patch
> > > > 
> > > > A regression against -mm1. This patch breaks bind (9.5.0-18.a7.fc8):
> > > > capset(0x19980330, 0,
> > > >
> > > {CAP_DAC_READ_SEARCH|CAP_SETGID|CAP_SETUID|CAP_NET_BIND_SERVICE|CAP_SYS_CHROOT|CAP_SYS_RESOURCE,
> > > >
> > > CAP_DAC_READ_SEARCH|CAP_SETGID|CAP_SETUID|CAP_NET_BIND_SERVICE|CAP_SYS_CHROOT|CAP_SYS_RESOURCE,
> > > > 0}) = -1 EPERM (Operation not permitted)
> > > > 
> > > > $ grep SEC .config
> > > > CONFIG_SECCOMP=y
> > > > # CONFIG_NETWORK_SECMARK is not set
> > > > CONFIG_RPCSEC_GSS_KRB5=m
> > > > # CONFIG_RPCSEC_GSS_SPKM3 is not set
> > > > # CONFIG_SECURITY is not set
> > > > # CONFIG_SECURITY_FILE_CAPABILITIES is not set
> > > > 
> > > > probably this hunk?:
> > > > @@ -133,6 +119,12 @@ int cap_capset_check (struct task_struct
> > > >                 /* incapable of using this inheritable set */
> > > >                 return -EPERM;
> > > >         }
> > > > +       if (!!cap_issubset(*inheritable,
> > > > +                          cap_combine(target->cap_inheritable,
> > > > +                                      current->cap_bset))) {
> > > > +               /* no new pI capabilities outside bounding set */
> > > > +               return -EPERM;
> > > > +       }
> > 
> > That shouldn't be it, since you can't lower cap_bset since
> > CONFIG_SECURITY_FILE_CAPABILITIES=n.
> 
> Hmm, but sure enough that appears to be it.
> 
> Still trying to figure out why.

No.  Seriously.  You're kidding me.

Patch attached  :(

Thanks for spotting this, Jiri.  I don't know where I introduced this
since I thought all my tests had passed...

thanks,
-serge

>From 70d5da610fdbd66a36886c01e27b7fb11d2de044 Mon Sep 17 00:00:00 2001
From: sergeh@...ibm.com <hallyn@...nel.(none)>
Date: Wed, 28 Nov 2007 16:16:23 -0800
Subject: [PATCH 1/1] capabilities: correct logic at capset_check

Fix typo at capset_check introduced with capability bounding set
patch.

Signed-off-by: sergeh@...ibm.com <hallyn@...nel.(none)>
---
 security/commoncap.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/security/commoncap.c b/security/commoncap.c
index c25ad09..503e958 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -119,7 +119,7 @@ int cap_capset_check (struct task_struct *target, kernel_cap_t *effective,
 		/* incapable of using this inheritable set */
 		return -EPERM;
 	}
-	if (!!cap_issubset(*inheritable,
+	if (!cap_issubset(*inheritable,
 			   cap_combine(target->cap_inheritable,
 				       current->cap_bset))) {
 		/* no new pI capabilities outside bounding set */
-- 
1.5.1

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/