CVE-2025-21872

Advisory lineage Upstream: 0 Downstream: 30
Modified
Published: 27 Mar 2025, 14:57
Last modified:11 May 2026, 21:08

Vulnerability Summary

Overall Risk (default)
low
22/100
CVSS Score
5.5 MEDIUM
v3.1 (nvd)
EPSS Score
0.02% LOW
0% probability -0.07%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

27 Mar 2025, 14:57
Published
Vulnerability first disclosed
11 May 2026, 21:08
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: efi: Don't map the entire mokvar table to determine its size Currently, when validating the mokvar table, we (re)map the entire table on each iteration of the loop, adding space as we discover new entries. If the table grows over a certain size, this fails due to limitations of early_memmap(), and we get a failure and traceback: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at mm/early_ioremap.c:139 __early_ioremap+0xef/0x220 ... Call Trace: <TASK> ? __early_ioremap+0xef/0x220 ? __warn.cold+0x93/0xfa ? __early_ioremap+0xef/0x220 ? report_bug+0xff/0x140 ? early_fixup_exception+0x5d/0xb0 ? early_idt_handler_common+0x2f/0x3a ? __early_ioremap+0xef/0x220 ? efi_mokvar_table_init+0xce/0x1d0 ? setup_arch+0x864/0xc10 ? start_kernel+0x6b/0xa10 ? x86_64_start_reservations+0x24/0x30 ? x86_64_start_kernel+0xed/0xf0 ? common_startup_64+0x13e/0x141 </TASK> ---[ end trace 0000000000000000 ]--- mokvar: Failed to map EFI MOKvar config table pa=0x7c4c3000, size=265187. Mapping the entire structure isn't actually necessary, as we don't ever need more than one entry header mapped at once. Changes efi_mokvar_table_init() to only map each entry header, not the entire table, when determining the table size. Since we're not mapping any data past the variable name, it also changes the code to enforce that each variable name is NUL terminated, rather than attempting to verify it in place.

CVSS Metrics

  • v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.02%• Percentile: 5%

Affected Systems

  • linux•linux

    ≥ 58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5, < 46c0454ffb78ce9d3355a3cccac86383ea8ddd55 | ≥ 58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5, < ea3f0b362dfe4ef885ef812bfaf4088176422c91 | ≥ 58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5, < 65f4aebb8127708ba668dd938e83b8558abfc5cd | ≥ 58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5, < 97bd560b6cc4c26386a53b4881bf03e96f9ba03a | ≥ 58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5, < 2b90e7ace79774a3540ce569e000388f8d22c9e0 | 5.10

  • linux•linux_kernel

    ≥ 5.10, < 5.10.235 | ≥ 5.11, < 6.6.83 | ≥ 6.7, < 6.12.18 | ≥ 6.13, < 6.13.6 | 6.14:rc1 | 6.14:rc2 | 6.14:rc3 | 6.14:rc4

References (6)