netdev - Re: [E1000-devel] networking probs in next-20081203

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: <1229117086.3134.22.camel@localhost.localdomain>
Date:	Fri, 12 Dec 2008 16:24:46 -0500
From:	Stephen Smalley <sds@...ho.nsa.gov>
To:	James Morris <jmorris@...ei.org>
Cc:	Alexey Dobriyan <adobriyan@...il.com>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	David Miller <davem@...emloft.net>, auke-jan.h.kok@...el.com,
	Andrew Morton <akpm@...ux-foundation.org>,
	e1000-devel@...ts.sourceforge.net, netdev@...r.kernel.org,
	Eric Paris <eparis@...isplace.org>,
	Daniel J Walsh <dwalsh@...hat.com>
Subject: Re: [E1000-devel] networking probs in next-20081203

On Fri, 2008-12-12 at 20:26 +1100, James Morris wrote:
> On Fri, 12 Dec 2008, Alexey Dobriyan wrote:
> 
> > Yes, please, someone test it.
> 
> Still getting avc denials:
> 
> avc:  denied  { mount } for  pid=2308 comm="dhclient" name="/" 
> dev=proc/net ino=4026531842 scontext=unconfined_u:system_r:dhcpc_t:s0-s0:c0.c1023 
> tcontext=system_u:object_r:proc_t:s0 tclass=filesystem
> type=SYSCALL msg=audit(1229073699.174:53): arch=c000003e syscall=2 
> success=no exit=-2 a0=45bef7 a1=80000 a2=1b6 a3=7f296
> e71c6f0 items=0 ppid=2259 pid=2308 auid=0 uid=0 gid=0 euid=0 suid=0 
> fsuid=0 egid=0 sgid=0 fsgid=0 tty=ttyS0 ses=1 comm="
> dhclient" exe="/sbin/dhclient" 
> subj=unconfined_u:system_r:dhcpc_t:s0-s0:c0.c1023 key=(null)
> 
> It seems the problem is that the /proc/net mountpoint is now labeled as 
> proc_t.

No, that's a check against the filesystem (superblock) label, not the
mountpoint directory.

proc_net_follow_link() creates a new mount, so we end up hitting
security_sb_kern_mount() => selinux_sb_kern_mount() and triggering this
permission check in the context of the current process on what is
supposed to be a kernel-internal mount of /proc/net.

Maybe pass flags down to security_sb_kern_mount() and skip the check in
the MS_KERNMOUNT case?

-- 
Stephen Smalley
National Security Agency

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html