Qemu emulator built with the AMD PC-Net II Ethernet Controller support is vulnerable to a heap buffer overflow flaw. While receiving packets in the loopback mode, it appends CRC code to the receive buffer. If the data size given is same as the receive buffer size, the appended CRC code overwrites 4 bytes beyond this 's->buffer' array. A privileged(CAP_SYS_RAWIO) user inside guest could use this flaw to crash the Qemu instance resulting in DoS or potentially execute arbitrary code with privileges of the Qemu process on the host. Upstream fix: ------------- -> http://git.qemu.org/?p=qemu.git;a=commit;h=837f21aacf5a714c23ddaadbbc5212f9 Reference: ---------- -> http://www.openwall.com/lists/oss-security/2015/11/30/2 -> http://www.openwall.com/lists/oss-security/2015/11/30/5
Statement: This issue does not affect the versions of the qemu-kvm packages as shipped with Red Hat Enterprise Linux 7 as they do not enable the pcnet backend driver. This issue does not affect the Red Hat Enterprise Linux 7 based versions of the qemu-kvm-rhev packages as shipped with Red Hat Enterprise Virtualization 3. This issue affects the versions of the kvm and xen packages as shipped with Red Hat Enterprise Linux 5, the versions of the qemu-kvm packages as shipped with Red Hat Enterprise Linux 6, and the Red Hat Enterprise Linux 6 based versions of qemu-kvm-rhev packages as shipped with Red Hat Enterprise Virtualization 3. Future updates for the respective releases may address this flaw. Please note that AMD PCNet adapter has to be explicitly enabled per-guest as it is not enabled in default configuration and is not supported by Red Hat in Red Hat Enterprise Linux 6 (for a list of supported devices please consult https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Virtualization_Administration_Guide/sect-whitelist-device-options.html). Red Hat Enterprise Linux 5 is now in Production 3 Phase of the support and maintenance life cycle. Though this has been rated as having Important 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/.
Acknowledgements: This issue was independently discovered by Qinghao Tang of QIHU 360 Marvel Team and Ling Liu of Qihoo 360 Inc.
*** Bug 1274344 has been marked as a duplicate of this bug. ***
Created xen tracking bugs for this issue: Affects: fedora-all [bug 1286544]
Created qemu tracking bugs for this issue: Affects: fedora-all [bug 1286543] Affects: epel-5 [bug 1286545] Affects: epel-7 [bug 1286547]
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.
This issue has been addressed in the following products: RHEV-H and Agents for RHEL-6 Via RHSA-2015:2696 https://rhn.redhat.com/errata/RHSA-2015-2696.html
This issue has been addressed in the following products: OpenStack 5 for RHEL 6 Via RHSA-2015:2695 https://rhn.redhat.com/errata/RHSA-2015-2695.html
This issue has been addressed in the following products: Red Hat Enterprise Linux 6 Via RHSA-2015:2694 https://rhn.redhat.com/errata/RHSA-2015-2694.html