Red Hat Bugzilla – Bug 144525
CAN-2005-0179 RLIMIT_MEMLOCK bypass and (2.6) unprivileged user DoS
Last modified: 2007-11-30 17:06:54 EST
*** This bug has been split off bug 144524 ***
------- Original comment by Josh Bressers (Security Response Team) on 2005.01.07
This was reported by grsecurity to full-disclosure
the 'culprit' patch is how the default RLIM_MEMLOCK and the privilege
to call mlockall have changed in 2.6.9. namely, the former has been
reduced to 32 pages while the latter has been relaxed to allow it for
otherwise unprivileged users if their RLIM_MEMLOCK is bigger than the
currently allocated vm. which is normally good enough, except as you
now know there's a path that can increase the allocated vm without
checking for RLIM_MEMLOCK.
The fix for this issue is attachment 109501 [details]
In rhel2.1 x86 mlock is restricted to root. Non-root users can not lock memory,
thus this is not a bug.