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From: "J. R. Okajima" <hooanon05@yahoo.co.jp>
To: James Morris <jmorris@namei.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Eric Paris <eparis@redhat.com>,
	linux-kernel@vger.kernel.org,
	linux-security-module@vger.kernel.org
Subject: Re: [GIT] Security updates for 3.3: SELinux
Date: Tue, 17 Jan 2012 23:28:03 +0900	[thread overview]
Message-ID: <12887.1326810483@jrobl> (raw)
In-Reply-To: <alpine.LRH.2.00.1201151322240.1430@tundra.namei.org>


James Morris:
> Eric Paris (12):
	:::
>       capabitlies: ns_capable can use the cap helpers rather than lsm call

After this commit, I am afraid access(2) on NFS may not work correctly.
The scenario based upon my guess.
- access(2) overrides the credentials.
- calls inode_permission() -- ... -- generic_permission() --
  ns_capable().
- while the old ns_capable() calls security_capable(current_cred()), the
  new ns_capable() calls has_ns_capability(current) --
  security_capable(__task_cred(t)).

current_cred() returns current->cred which is effective (overridden)
credentials, but __task_cred(current) returns current->real_cred (the
NFSD's credential). And the overridden credentials by access(2) lost.

Is my guess correct?


J. R. Okajima

  parent reply	other threads:[~2012-01-17 14:28 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-15  2:25 [GIT] Security updates for 3.3: SELinux James Morris
2012-01-15  2:54 ` Linus Torvalds
2012-01-15  4:04   ` James Morris
2012-01-17 14:28 ` J. R. Okajima [this message]
2012-01-17 14:38   ` Eric Paris

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