In the Linux kernel, the following vulnerability has been resolved:
nios2: ensure that memblock.current_limit is set when setting pfn limits
On nios2, with CONFIG_FLATMEM set, the kernel relies on
memblock_get_current_limit() to determine the limits of mem_map, in
particular for max_low_pfn.
Unfortunately, memblock.current_limit is only default initialized to
MEMBLOCK_ALLOC_ANYWHERE at this point of the bootup, potentially leading
to situations where max_low_pfn can erroneously exceed the value of
max_pfn and, thus, the valid range of available DRAM.
This can in turn cause kernel-level paging failures, e.g.:
[ 76.900000] Unable to handle kernel paging request at virtual address 20303000
[ 76.900000] ea = c0080890, ra = c000462c, cause = 14
[ 76.900000] Kernel panic - not syncing: Oops
[ 76.900000] ---[ end Kernel panic - not syncing: Oops ]---
This patch fixes this by pre-calculating memblock.current_limit
based on the upper limits of the available memory ranges via
adjust_lowmem_bounds, a simplified version of the equivalent
implementation within the arm architecture.
Metrics
Affected Vendors & Products
References
History
Sat, 06 Dec 2025 00:15:00 +0000
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threat_severity
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cvssV3_1
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Thu, 04 Dec 2025 15:45:00 +0000
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| Description | In the Linux kernel, the following vulnerability has been resolved: nios2: ensure that memblock.current_limit is set when setting pfn limits On nios2, with CONFIG_FLATMEM set, the kernel relies on memblock_get_current_limit() to determine the limits of mem_map, in particular for max_low_pfn. Unfortunately, memblock.current_limit is only default initialized to MEMBLOCK_ALLOC_ANYWHERE at this point of the bootup, potentially leading to situations where max_low_pfn can erroneously exceed the value of max_pfn and, thus, the valid range of available DRAM. This can in turn cause kernel-level paging failures, e.g.: [ 76.900000] Unable to handle kernel paging request at virtual address 20303000 [ 76.900000] ea = c0080890, ra = c000462c, cause = 14 [ 76.900000] Kernel panic - not syncing: Oops [ 76.900000] ---[ end Kernel panic - not syncing: Oops ]--- This patch fixes this by pre-calculating memblock.current_limit based on the upper limits of the available memory ranges via adjust_lowmem_bounds, a simplified version of the equivalent implementation within the arm architecture. | |
| Title | nios2: ensure that memblock.current_limit is set when setting pfn limits | |
| First Time appeared |
Linux
Linux linux Kernel |
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| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
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| References |
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Status: PUBLISHED
Assigner: Linux
Published: 2025-12-04T15:31:34.142Z
Updated: 2025-12-04T15:31:34.142Z
Reserved: 2025-04-16T07:20:57.181Z
Link: CVE-2025-40245
No data.
Status : Awaiting Analysis
Published: 2025-12-04T16:16:17.827
Modified: 2025-12-04T17:15:08.283
Link: CVE-2025-40245