Description
In the Linux kernel, the following vulnerability has been resolved: x86/mm/ident_map: Use gbpages only where full GB page should be mapped. When ident_pud_init() uses only GB pages to create identity maps, large ranges of addresses not actually requested can be included in the resulting table; a 4K request will map a full GB. This can include a lot of extra address space past that requested, including areas marked reserved by the BIOS. That allows processor speculation into reserved regions, that on UV systems can cause system halts. Only use GB pages when map creation requests include the full GB page of space. Fall back to using smaller 2M pages when only portions of a GB page are included in the request. No attempt is made to coalesce mapping requests. If a request requires a map entry at the 2M (pmd) level, subsequent mapping requests within the same 1G region will also be at the pmd level, even if adjacent or overlapping such requests could have been combined to map a full GB page. Existing usage starts with larger regions and then adds smaller regions, so this should not have any great consequence.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
66aad4fdf2bf0af29c7decb4433dc5ec6c7c5451 to < cb2555fb0223edac9e7820f16de17ae04a39ad39affected66aad4fdf2bf0af29c7decb4433dc5ec6c7c5451 to < fe9bab1d6441ed49dc3dd0acce4c2215e8d85447affected66aad4fdf2bf0af29c7decb4433dc5ec6c7c5451 to < d113f9723f2bfd9c6feeb899b8ddbee6b8a6e01faffected66aad4fdf2bf0af29c7decb4433dc5ec6c7c5451 to < d80a99892f7a992d103138fa4636b2c33abd6740affected66aad4fdf2bf0af29c7decb4433dc5ec6c7c5451 to < a23823098ab2c277c14fc110b97d8d5c83597195affected66aad4fdf2bf0af29c7decb4433dc5ec6c7c5451 to < cc31744a294584a36bf764a0ffa3255a8e69f036affected
Linux Linux
Default version status: affected
4.12affected0 to < 4.12unaffected5.15.221 to ≤ 5.15.*unaffected6.1.188 to ≤ 6.1.*unaffected6.6.78 to ≤ 6.6.*unaffected6.10.14 to ≤ 6.10.*unaffected6.11.3 to ≤ 6.11.*unaffected6.12 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/cb2555fb0223edac9e7820f16de17ae04a39ad39 ↗
- https://git.kernel.org/stable/c/fe9bab1d6441ed49dc3dd0acce4c2215e8d85447 ↗
- https://git.kernel.org/stable/c/d113f9723f2bfd9c6feeb899b8ddbee6b8a6e01f ↗
- https://git.kernel.org/stable/c/d80a99892f7a992d103138fa4636b2c33abd6740 ↗
- https://git.kernel.org/stable/c/a23823098ab2c277c14fc110b97d8d5c83597195 ↗
- https://git.kernel.org/stable/c/cc31744a294584a36bf764a0ffa3255a8e69f036 ↗