Description of problem: Eugene Teo discovered that range_is_allowed() check is only added in {read,write}_mem(). It is possible for an illegitimate application to bypass these checks, and access /dev/mem beyond the 1M limit by calling mmap_mem() instead.
phalanx2 rootkit uses mmap to bypass the check, and access /dev/mem between 0 and 8000000. By adding the range_is_allow() check in mmap_mem(), it is possible to prevent phalanx2 or any other illegitimate application from injecting code into /dev/mem. =*=*=*=*=*=*=*=*=*=*=*=*=*=*= | phalanx2 | | %rebel% . 2008 | =*=*=*=*=*=*=*=*=*=*=*=*=*=*= AUDIT_STATUS: enabled=0 flag=1 pid=4436 rate_limit=0 backlog_limit=320 lost=0 backlog=0 :( could not map memory mmap2(NULL, 134217728, PROT_READ|PROT_WRITE, MAP_SHARED, 3, 0) = -1 EPERM (Operation not permitted) References: http://isc.sans.org/diary.html?storyid=4937 http://hep.uchicago.edu/admin/report_072808.html
This appears to be fixed in upstream since commit e2beb3eae.
I suggest to use this: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=e2beb3eae627211b67e456c53f946cede2ac10d7
(In reply to comment #6) > I suggest to use this: > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=e2beb3eae627211b67e456c53f946cede2ac10d7 Agree that we should stay closer to upstream. I will re-backport the patch. Thanks, Eugene
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
in kernel-2.6.18-113.el5 You can download this test kernel from http://people.redhat.com/dzickus/el5
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2009-0225.html