{"cve":"CVE-2025-21872","nvd":{"published":"2025-03-27T15:15:54.973","modified":"2026-10-30T13:17:53.200","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nefi: Don't map the entire mokvar table to determine its size\n\nCurrently, when validating the mokvar table, we (re)map the entire table\non each iteration of the loop, adding space as we discover new entries.\nIf the table grows over a certain size, this fails due to limitations of\nearly_memmap(), and we get a failure and traceback:\n\n  ------------[ cut here ]------------\n  WARNING: CPU: 0 PID: 0 at mm/early_ioremap.c:139 __early_ioremap+0xef/0x220\n  ...\n  Call Trace:\n   <TASK>\n   ? __early_ioremap+0xef/0x220\n   ? __warn.cold+0x93/0xfa\n   ? __early_ioremap+0xef/0x220\n   ? report_bug+0xff/0x140\n   ? early_fixup_exception+0x5d/0xb0\n   ? early_idt_handler_common+0x2f/0x3a\n   ? __early_ioremap+0xef/0x220\n   ? efi_mokvar_table_init+0xce/0x1d0\n   ? setup_arch+0x864/0xc10\n   ? start_kernel+0x6b/0xa10\n   ? x86_64_start_reservations+0x24/0x30\n   ? x86_64_start_kernel+0xed/0xf0\n   ? common_startup_64+0x13e/0x141\n   </TASK>\n  ---[ end trace 0000000000000000 ]---\n  mokvar: Failed to map EFI MOKvar config table pa=0x7c4c3000, size=265187.\n\nMapping the entire structure isn't actually necessary, as we don't ever\nneed more than one entry header mapped at once.\n\nChanges efi_mokvar_table_init() to only map each entry header, not the\nentire table, when determining the table size.  Since we're not mapping\nany data past the variable name, it also changes the code to enforce\nthat each variable name is NUL terminated, rather than attempting to\nverify it in place.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/2b90e7ace79774a3540ce569e000388f8d22c9e0","https://git.kernel.org/stable/c/46c0454ffb78ce9d3355a3cccac86383ea8ddd55","https://git.kernel.org/stable/c/65f4aebb8127708ba668dd938e83b8558abfc5cd","https://git.kernel.org/stable/c/97bd560b6cc4c26386a53b4881bf03e96f9ba03a","https://git.kernel.org/stable/c/ea3f0b362dfe4ef885ef812bfaf4088176422c91"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-30T13:47:47.119061695+00:00"},"epss":{"cve":"CVE-2025-21872","score":0.00208,"percentile":0.10942,"date":"2026-10-30"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}