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.
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
58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5 to < 46c0454ffb78ce9d3355a3cccac86383ea8ddd55affected58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5 to < f17a72ac7dd6f9469c9e6185bdbb22dbb744dd74affected58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5 to < ea3f0b362dfe4ef885ef812bfaf4088176422c91affected58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5 to < 65f4aebb8127708ba668dd938e83b8558abfc5cdaffected58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5 to < 97bd560b6cc4c26386a53b4881bf03e96f9ba03aaffected58c909022a5a56cd1d9e89c8c5461fd1f6a27bb5 to < 2b90e7ace79774a3540ce569e000388f8d22c9e0affected
Linux Linux
Default version status: affected
5.10affected0 to < 5.10unaffected5.10.235 to ≤ 5.10.*unaffected6.1.191 to ≤ 6.1.*unaffected6.6.83 to ≤ 6.6.*unaffected6.12.18 to ≤ 6.12.*unaffected6.13.6 to ≤ 6.13.*unaffected6.14 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/46c0454ffb78ce9d3355a3cccac86383ea8ddd55 ↗
- https://git.kernel.org/stable/c/f17a72ac7dd6f9469c9e6185bdbb22dbb744dd74 ↗
- https://git.kernel.org/stable/c/ea3f0b362dfe4ef885ef812bfaf4088176422c91 ↗
- https://git.kernel.org/stable/c/65f4aebb8127708ba668dd938e83b8558abfc5cd ↗
- https://git.kernel.org/stable/c/97bd560b6cc4c26386a53b4881bf03e96f9ba03a ↗
- https://git.kernel.org/stable/c/2b90e7ace79774a3540ce569e000388f8d22c9e0 ↗
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html ↗