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.
Metrics
Affected Vendors & Products
References
History
Thu, 30 Oct 2025 16:30:00 +0000
Type | Values Removed | Values Added |
---|---|---|
First Time appeared |
Linux
Linux linux Kernel |
|
Weaknesses | NVD-CWE-noinfo | |
CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:* |
|
Vendors & Products |
Linux
Linux linux Kernel |
Wed, 02 Apr 2025 02:15:00 +0000
Type | Values Removed | Values Added |
---|---|---|
References |
| |
Metrics |
threat_severity
|
cvssV3_1
|
Thu, 27 Mar 2025 15:15:00 +0000
Type | Values Removed | Values Added |
---|---|---|
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. | |
Title | efi: Don't map the entire mokvar table to determine its size | |
References |
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-05-10T16:48:44.937Z
Reserved: 2024-12-29T08:45:45.781Z
Link: CVE-2025-21872

No data.

Status : Analyzed
Published: 2025-03-27T15:15:54.973
Modified: 2025-10-30T16:19:31.910
Link: CVE-2025-21872
