Scientific Linux SL5.x SLSA-2016:2124-1 Important: Kernel Escalation Risks

Date: Fri, 28 Oct 2016 15:55:02 -0000
Reply-To: scientific-linux-users@
Sender: Security Errata for Scientific Linux
 
From: Pat Riehecky 
Subject: Security ERRATA Important: kernel on SL5.x i386/x86_64
MIME-Version: 1.0
Message-ID: <20161028155502.7496.31783@slpackages.fnal.gov>

Synopsis: Important: kernel security and bug fix update
Advisory ID: SLSA-2016:2124-1
Issue Date: 2016-10-28
CVE Numbers: CVE-2016-5195
 CVE-2016-1583
--

Security Fix(es):

* A race condition was found in the way the Linux kernel's memory
subsystem handled the copy-on-write (COW) breakage of private read-only
memory mappings. An unprivileged, local user could use this flaw to gain
write access to otherwise read-only memory mappings and thus increase
their privileges on the system. (CVE-2016-5195, Important)

* It was found that stacking a file system over procfs in the Linux kernel
could lead to a kernel stack overflow due to deep nesting, as demonstrated
by mounting ecryptfs over procfs and creating a recursion by mapping
/proc/environ. An unprivileged, local user could potentially use this flaw
to escalate their privileges on the system. (CVE-2016-1583, Important)

Bug Fix(es):

* In some cases, a kernel crash or file system corruption occurred when
running journal mode 'ordered'. The kernel crash was caused by a null
pointer dereference due to a race condition between two journal functions.
The file system corruption occurred due to a race condition between the
do_get_write_access() function and buffer writeout. This update fixes both
race conditions. As a result, neither the kernel crash, nor the file
system corruption now occur.

* Prior to this update, some Global File System 2 (GFS2) files had
incorrect time stamp values due to two problems with handling time stamps
of such files. The first problem concerned the atime time stamp, which
ended up with an arbitrary value ahead of the actual value, when a GFS2
file was accessed. The second problem was related to the mtime and ctime
time stamp updates, which got lost when a GFS2 file was written to from
one node and read from or written to from another node. With this update,
a set of patches has been applied that fix these problems. As a result,
the time stamps of GFS2 files are now handled correctly.
--

SL5
 x86_64
 kernel-2.6.18-416.el5.x86_64.rpm
 kernel-debug-2.6.18-416.el5.x86_64.rpm
 kernel-debug-debuginfo-2.6.18-416.el5.x86_64.rpm
 kernel-debug-devel-2.6.18-416.el5.x86_64.rpm
 kernel-debuginfo-2.6.18-416.el5.x86_64.rpm
 kernel-debuginfo-common-2.6.18-416.el5.x86_64.rpm
 kernel-devel-2.6.18-416.el5.x86_64.rpm
 kernel-headers-2.6.18-416.el5.x86_64.rpm
 kernel-xen-2.6.18-416.el5.x86_64.rpm
 kernel-xen-debuginfo-2.6.18-416.el5.x86_64.rpm
 kernel-xen-devel-2.6.18-416.el5.x86_64.rpm
 i386
 kernel-2.6.18-416.el5.i686.rpm
 kernel-PAE-2.6.18-416.el5.i686.rpm
 kernel-PAE-debuginfo-2.6.18-416.el5.i686.rpm
 kernel-PAE-devel-2.6.18-416.el5.i686.rpm
 kernel-debug-2.6.18-416.el5.i686.rpm
 kernel-debug-debuginfo-2.6.18-416.el5.i686.rpm
 kernel-debug-devel-2.6.18-416.el5.i686.rpm
 kernel-debuginfo-2.6.18-416.el5.i686.rpm
 kernel-debuginfo-common-2.6.18-416.el5.i686.rpm
 kernel-devel-2.6.18-416.el5.i686.rpm
 kernel-headers-2.6.18-416.el5.i386.rpm
 kernel-xen-2.6.18-416.el5.i686.rpm
 kernel-xen-debuginfo-2.6.18-416.el5.i686.rpm
 kernel-xen-devel-2.6.18-416.el5.i686.rpm
 noarch
 kernel-doc-2.6.18-416.el5.noarch.rpm

- Scientific Linux Development Team
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