Re: [PATCH] shmtcl SHM_LOCK perms

[Chris Wright]

* Hugh Dickins (hugh@xxxxxxxxxxx) wrote:
> Michael Kerrisk has observed that at present any process can SHM_LOCK
> any shm segment of size within process RLIMIT_MEMLOCK, despite having no
> permissions on the segment: surprising, though not obviously evil.  And
> any process can SHM_UNLOCK any shm segment, despite no permissions on it:
> that is surely wrong.

You may be neither the owner, nor the creator of a segment but have read
access to it.  In which case you could simply copy the contents of the
segment anywhere you like, which has similar effect to SHM_UNLOCK from
the point of view of paging out sensitive data.

thanks,
-chris
-- 
Linux Security Modules     http://lsm.immunix.org     http://lsm.bkbits.net
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