{"id":"CVE-2026-53288","summary":"arm64: Reserve an extra page for early kernel mapping","details":"In the Linux kernel, the following vulnerability has been resolved:\n\narm64: Reserve an extra page for early kernel mapping\n\nThe final part of [data, end) segment may overflow into the next page of\ninit_pg_end[1] which is the gap page before early_init_stack[2]:\n\n[1]\ncrash_arm64_v9.0.1\u003e vtop ffffffed00601000\nVIRTUAL           PHYSICAL\nffffffed00601000  83401000\n\nPAGE DIRECTORY: ffffffecffd62000\n   PGD: ffffffecffd62da0 =\u003e 10000000833fb003\n   PMD: ffffff80033fb018 =\u003e 10000000833fe003\n   PTE: ffffff80033fe008 =\u003e 68000083401f03\n  PAGE: 83401000\n\n     PTE        PHYSICAL  FLAGS\n68000083401f03  83401000  (VALID|SHARED|AF|NG|PXN|UXN)\n\n      PAGE       PHYSICAL      MAPPING       INDEX CNT FLAGS\nfffffffec00d0040 83401000                0        0  1 4000 reserved\n\n[2]\nffffffed002c8000 (r) __pi__data\nffffffed0054e000 (d) __pi___bss_start\nffffffed005f5000 (b) __pi_init_pg_dir\nffffffed005fe000 (b) __pi_init_pg_end\nffffffed005ff000 (B) early_init_stack\nffffffed00608000 (b) __pi__end\n\nFor 4K pages, the early kernel mapping may use 2MB block entries but the\nkernel segments are only 64KB aligned. Segment boundaries that fall\nwithin a 2MB block therefore require a PTE table so that different\nattributes can be applied on either side of the boundary.\n\nKERNEL_SEGMENT_COUNT still correctly counts the five permanent kernel\nVMAs registered by declare_kernel_vmas(). However, since commit\n5973a62efa34 (\"arm64: map [_text, _stext) virtual address range\nnon-executable+read-only\"), the early mapper also maps [_text, _stext)\nseparately from [_stext, _etext). This adds one more early-only split\nand can require one more page-table page than the existing\nEARLY_SEGMENT_EXTRA_PAGES allowance reserves.\n\nIncrease the 4K-page early mapping allowance by one page to cover that\nadditional split.\n\n[catalin.marinas@arm.com: rewrote part of the commit log]\n[catalin.marinas@arm.com: expanded the code comment]","modified":"2026-10-28T02:30:46.502922948Z","published":"2026-06-26T19:40:48.528Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53288.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/4d8e74ad4585672489da6145b3328d415f50db82"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9fe9e3acaa14921b0cf0d6cc2de5b562499bf721"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a4ff33053da0a34b14abb5c96dc5a48379e26fce"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dcb89deed40ba55ff7020061712fdabf098cc2cc"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53288.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53288"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"fdd380a5950503a07aaaf74536a0c2f223475eb0"},{"fixed":"a4ff33053da0a34b14abb5c96dc5a48379e26fce"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5973a62efa34c80c9a4e5eac1fca6f6209b902af"},{"fixed":"dcb89deed40ba55ff7020061712fdabf098cc2cc"},{"fixed":"9fe9e3acaa14921b0cf0d6cc2de5b562499bf721"},{"fixed":"4d8e74ad4585672489da6145b3328d415f50db82"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.12.54"},{"fixed":"6.12.91"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.17.4"},{"fixed":"6.18"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"88025faf2aa08c7468d68d8cb31a53b55aae6ee0"}]}],"versions":["v6.12.90","v6.12.89","v6.12.88","v6.12.87","v6.12.86","v6.12.85","v6.12.84","v6.12.83","v6.12.82","v6.12.81","v6.12.80","v6.12.79","v6.12.78","v6.12.77","v6.12.76","v6.12.75","v6.12.74","v6.12.73","v6.12.72","v6.12.71","v6.12.70","v6.12.69","v6.12.68","v6.12.67","v6.12.66","v6.12.65","v6.12.64","v6.12.63","v6.12.62","v6.12.61","v6.12.60","v6.12.59","v6.12.58","v6.12.57","v6.12.56","v6.12.55","v6.12.54","v6.17.13","v6.17.12","v6.17.11","v6.17.10","v6.17.9","v6.17.8","v6.17.7","v6.17.6","v6.17.5","v6.17.4"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53288.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.12.91"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.33"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.18.0"},{"fixed":"7.0.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53288.json"}}],"schema_version":"1.9.2"}