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In the Linux kernel, the following vulnerability has been resolved:

kho: skip KHO for crash kernel

kho_fill_kimage() unconditionally populates the kimage with KHO metadata for every kexec image type. When the image is a crash kernel, this can be problematic as the crash kernel can run in a small reserved region and the KHO scratch areas can sit outside it. The crash kernel then faults during kho_memory_init() when it tries phys_to_virt() on the KHO FDT address:

Unable to handle kernel paging request at virtual address xxxxxxxx ... fdt_offset_ptr+... fdt_check_node_offset_+... fdt_first_property_offset+... fdt_get_property_namelen_+... fdt_getprop+... kho_memory_init+... mm_core_init+... start_kernel+...

kho_locate_mem_hole() already skips KHO logic for KEXEC_TYPE_CRASH images, but kho_fill_kimage() was missing the same guard. As kho_fill_kimage() is the single point that populates image->kho.fdt and image->kho.scratch, fixing it here is sufficient for both arm64 and x86 as the FDT and boot_params path are bailing out when these fields are unset.

In the Linux kernel, the following vulnerability has been resolved:

kho: skip KHO for crash kernel

kho_fill_kimage() unconditionally populates the kimage with KHO metadata for every kexec image type. When the image is a crash kernel, this can be problematic as the crash kernel can run in a small reserved region and the KHO scratch areas can sit outside it. The crash kernel then faults during kho_memory_init() when it tries phys_to_virt() on the KHO FDT address:

Unable to handle kernel paging request at virtual address xxxxxxxx ... fdt_offset_ptr+... fdt_check_node_offset_+... fdt_first_property_offset+... fdt_get_property_namelen_+... fdt_getprop+... kho_memory_init+... mm_core_init+... start_kernel+...

kho_locate_mem_hole() already skips KHO logic for KEXEC_TYPE_CRASH images, but kho_fill_kimage() was missing the same guard. As kho_fill_kimage() is the single point that populates image->kho.fdt and image->kho.scratch, fixing it here is sufficient for both arm64 and x86 as the FDT and boot_params path are bailing out when these fields are unset.

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 111 more

In the Linux kernel, the following vulnerability has been resolved: kho: skip KHO for crash kernel kho_fill_kimage() unconditionally populates the kimage with KHO metadata for every kexec image type. When the image is a crash kernel, this can be problematic as the crash kernel can run in a small reserved region and the KHO scratch areas can sit outside it. The crash kernel then faults during kho_memory_init() when it tries phys_to_virt() on the KHO FDT address: Unable to handle kernel paging request at virtual address xxxxxxxx ... fdt_offset_ptr+... fdt_check_node_offset_+... fdt_first_property_offset+... fdt_get_property_namelen_+... fdt_getprop+... kho_memory_init+... mm_core_init+... start_kernel+... kho_locate_mem_hole() already skips KHO logic for KEXEC_TYPE_CRASH images, but kho_fill_kimage() was missing the same guard. As kho_fill_kimage() is the single point that populates image->kho.fdt and image->kho.scratch, fixing it here is sufficient for both arm64 and x86 as the FDT and boot_params path are bailing out when these fields are unset.

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen, möglicherweise Sicherheitsmaßnahmen zu umgehen, einen Denial-of-Service-Zustand herbeizuführen oder vertrauliche Informationen offenzulegen.