Qemu emulator built with the i8255x (PRO100) emulation support is vulnerable to an infinite loop issue. It could occur while processing a chain of commands located in the Command Block List(CBL). Each Command Block(CB) points to the next command in the list. An infinite loop unfolds if the link to the next CB points to the same block or there is a closed loop in the chain. A privileged(CAP_SYS_RAWIO) user inside guest could use this flaw to crash the Qemu instance resulting in DoS. Upstream patch: --------------- -> https://lists.gnu.org/archive/html/qemu-devel/2015-10/msg03911.html Reference: ---------- -> http://www.openwall.com/lists/oss-security/2015/11/25/11
Created xen tracking bugs for this issue: Affects: fedora-all [bug 1285215]
Created qemu tracking bugs for this issue: Affects: fedora-all [bug 1285214]
Acknowledgements: This issue was discovered by Qinghao Tang of QIHU 360 Marvel Team.
Statement: This issue affects the kvm package as shipped with Red Hat Enterprise Linux 5. This issue affects the versions of the qemu-kvm packages as shipped with Red Hat Enterprise Linux 6 and 7. This issue affects the Red Hat Enterprise Linux 6 based versions of qemu-kvm-rhev packages as shipped with Red Hat Enterprise Virtualization 3. This issue affects the Red Hat Enterprise Linux 7 based versions of the qemu-kvm-rhev packages as shipped with Red Hat Enterprise Virtualization 3. This has been rated as having Moderate security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/
xen-4.5.2-5.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.
qemu-2.4.1-2.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.
xen-4.5.2-5.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.