Xen Security Advisory XSA-210 arm: memory corruption when freeing p2m pages ISSUE DESCRIPTION ================= When freeing pages used for stage-2 page tables, the freeing routine failed to remove these pages from an internally managed list they were put on during allocation. The same list node elements are also used by the hypervisor's page allocator. Subsequent manipulation of ARM's private P2M list could therefore corrupt the lists maintained by the page allocator. The buggy code is exposed to guests via the XENMEM_decrease_reservation hypercall. IMPACT ====== A malicious or buggy guest may corrupt hypervisor state, commonly leading to a host crash (Denial of Service). Privilege escalation or information leaks cannot be excluded. VULNERABLE SYSTEMS ================== Only Xen version 4.8 is affected. Xen versions 4.7 and earlier are not vulnerable. Only ARM systems are vulnerable. X86 based systems are not vulnerable. MITIGATION ========== There is no known mitigation. NOTE REGARDING LACK OF EMBARGO ============================== The issue was discussed publicly before being recognized as a security issue. RESOLUTION ========== Applying the attached patch resolves this issue. xsa210.patch xen-unstable, Xen 4.8.x $ sha256sum xsa210* 10e26c017c916dcac261c6a3c92656831f0ad037f792940e6faf6905c6e23861 xsa210.patch $ CREDITS ======= The initial bug was discovered by Vijay Kilari of Cavium and the security aspect was diagnosed by Julien Grall of ARM.
Is this fixed in? - app-emulation/{xen-4.7.2-r1,{xen-pvgrub,sen-tools}-4.7.2} as was stabilized in bug #615980?
yes, it's fixed at >=app-emulation/xen-4.8.0-r3, see commit 5fbfb0c17adb82de0885eec625afe300781927c8 Author: Yixun Lan <dlan@gentoo.org> Date: Fri Feb 24 17:33:55 2017 +0800 app-emulation/xen: fix XSA-210 arm: memory corruption when freeing p2m pages Package-Manager: Portage-2.3.3, Repoman-2.3.1
