Linux kernel is found to be vulnerable to a NULL pointer dereference flaw caused due to inappropriate handling of Floating Point Unit(FPU) exceptions during task switch at 'emms' instruction. This only affects AMD CPU family in both i386 & AMD64 modes. A user/program could use this flaw to kill tasks at random resulting in DoS or potentially gain root privileges if allowed to map NULL(mmap_min_addr=0) page. Upstream fix: ------------- -> https://git.kernel.org/linus/26bef1318adc1b3a530ecc807ef99346db2aa8b0 Reference: ---------- -> https://lkml.org/lkml/2013/12/28/95 -> http://www.openwall.com/lists/oss-security/2014/01/12/1 -> http://www.halfdog.net/Security/2013/Vm86SyscallTaskSwitchKernelPanic/
Statement: This issue does not affect the versions of Linux kernel as shipped with Red Hat Enterprise Linux 5 and Red Hat Enterprise Linux 6.
Created kernel tracking bugs for this issue: Affects: fedora-all [bug 1053599]
kernel-3.12.8-200.fc19 has been pushed to the Fedora 19 stable repository. If problems still persist, please make note of it in this bug report.
kernel-3.12.8-300.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.
This issue has been addressed in following products: MRG for RHEL-6 v.2 Via RHSA-2014:0439 https://rhn.redhat.com/errata/RHSA-2014-0439.html