Re: [GIT] Security updates for 3.3: SELinux

From: J. R. Okajima
Date: Tue Jan 17 2012 - 09:28:22 EST



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
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