mm/damon/core: handle region split failure in apply_min_nr_regions()
In the Linux kernel, the following vulnerability has been resolved: mm/damon/core: handle region split failure in apply_min_nr_regions() damon_apply_min_nr_regions() repeatedly split each region until its size becomes small enough to meet the user-defined low limit of the number of regions. The loop assumes the split operation (damon_split_region_at()) will always succeed and create the new region. But the operation could silently fail for memory allocation failures, for example. If such failure happens and the region was the last region, the linked list-based next region fetching returns invalid pointer. As a result, invalid memory dereference and corruption could happen. Even if the corner case is handled, it imposes stress to the allocator by trying split regions for other targets. Fix the issue by breaking all the loops for any region split failure. This means there could be a min_nr_regions violation. It will only rarely happen since the allocation is arguably too small to fail. Even if it happens, it is only temporal. damon_apply_min_nr_regions() will be called again after the aggregation interval. The user impact of the issue should be minor, since the allocation is arguably too small to fail. But, it could still theoretically happen, and the consequence is very bad. This issue was discovered [1] by Sashiko.
CVE-2026-90004
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-90004
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "b1029f29eb1d5fbf07fa8db9b5e7ab6d9813ad67",
"lessThan": "463ebd63e8ee3d73022a18915ea43320dad8aad7",
"versionType": "git"
},
{
"status": "affected",
"version": "b1029f29eb1d5fbf07fa8db9b5e7ab6d9813ad67",
"lessThan": "c608748607620f331196ed0ba9fe4017892c1457",
"versionType": "git"
}
],
"programFiles": [
"mm/damon/core.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "7.1"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "7.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "7.2.5",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"mm/damon/core.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-90004
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #36437 · Revision 1
- Added to Heist Feed
- Publisher date