| Description |
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An issue was discovered in the Linux kernel as used by Xen. A Dom0 or driver domain based on a Linux kernel (configured as described above) can be crashed by a malicious guest administrator, or possibly malicious unprivileged guest processes. Only Linux kernels configured with CONFIG_XEN_UNPOPULATED_ALLOC and without CONFIG_XEN_BALLOON_MEMORY_HOTPLUG are vulnerable. Only kernels from kernel version 5.9 onwards are affected. CONFIG_XEN_BALLOON_MEMORY_HOTPLUG is enabled by default in upstream Linux when Xen support is enabled, so kernels using upstream default Kconfig are not affected. Most distribution kernels supporting Xen dom0 use are likewise not vulnerable. |
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An issue was discovered in the Linux kernel 5.9.x through 5.11.3, as used with Xen. In some less-common configurations, an x86 PV guest OS user can crash a Dom0 or driver domain via a large amount of I/O activity. The issue relates to misuse of guest physical addresses when a configuration has CONFIG_XEN_UNPOPULATED_ALLOC but not CONFIG_XEN_BALLOON_MEMORY_HOTPLUG. |
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