powerpc/kexec_file: Prevent kexec range truncation
Summary
| CVE | CVE-2026-89962 |
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| State | PUBLISHED |
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| Assigner | Linux |
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| Source Priority | CVE Program / NVD first with legacy fallback |
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| Published | 2026-09-16 11:17:06 UTC |
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| Updated | 2026-09-16 11:17:06 UTC |
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| Description | In the Linux kernel, the following vulnerability has been resolved:
powerpc/kexec_file: Prevent kexec range truncation
Sashiko AI review pointed out the following issue.
The __merge_memory_ranges() function incorrectly handles overlapping
memory ranges when merging them. Although sort_memory_ranges() sorts all
ranges by their start address in ascending order beforehand, the merge
logic remains defective in two ways:
1. It compares the current range's start against the previous element (i-1)
instead of the running target index (idx)
2. It unconditionally overwrites 'ranges[idx].end' with 'ranges[i].end'.
This logic flaw leads to critical memory truncation when a larger memory
range completely subsumes subsequent smaller ranges.
For example, consider a sorted input array with three ranges:
Range A (idx=0): [0x1000 - 0x9000]
Range B (i=1): [0x2000 - 0x5000] (completely inside Range A)
Range C (i=2): [0x6000 - 0x8000] (completely inside Range A)
1. When i=1 (Range B):
ranges[1].start (0x2000) <= ranges[0].end + 1 (0x9001) is TRUE.
The code executes: ranges[0].end = ranges[1].end, which erroneously
shrinks Range A's end from 0x9000 down to 0x5000.
2. When i=2 (Range C):
ranges[2].start (0x6000) <= ranges[1].end + 1 (0x5001) is FALSE.
The code falls into the else block, creating a broken new range.
As a result, valid memory fragments [0x5001 - 0x5fff] and [0x8001 - 0x9000]
are completely lost from the kexec exclude lists, potentially allowing
the crash kernel to overwrite active memory, causing data corruption
or crashes.
Fix this by ensuring the start of the current range is compared against the
end of the active merged range (idx), and use max() to safely prevent the
outer boundary from being truncated. |
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Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected 180adfc532a83c1d74146449f7385f767d4b8059 9ef63622e6cee588ea4b763a6afc87065254b36a git |
Not specified |
| CNA |
Linux |
Linux |
affected 180adfc532a83c1d74146449f7385f767d4b8059 da88a2a2119e4fd0e8919a7a2448682f574e1545 git |
Not specified |
| CNA |
Linux |
Linux |
affected 180adfc532a83c1d74146449f7385f767d4b8059 c4cb547f26d9b73b489c5278d0c8db837c5a174f git |
Not specified |
| CNA |
Linux |
Linux |
affected 180adfc532a83c1d74146449f7385f767d4b8059 fa40f9dbdd4af53e7445d9135b5b207eb8adf372 git |
Not specified |
| CNA |
Linux |
Linux |
affected 5.9 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.9 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.12.110 6.12.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.51 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2.5 7.2.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.3-rc1 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/9ef63622e6cee588ea4b763a6afc87065254b36a |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/da88a2a2119e4fd0e8919a7a2448682f574e1545 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/fa40f9dbdd4af53e7445d9135b5b207eb8adf372 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/c4cb547f26d9b73b489c5278d0c8db837c5a174f |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.