mm/slab: do not limit zeroing to orig_size when only red zoning is enabled
In the Linux kernel, the following vulnerability has been resolved: mm/slab: do not limit zeroing to orig_size when only red zoning is enabled When init (zeroing) on allocation is requested, for kmalloc() we generally have to zero the full object size even if a smaller size is requested, in order to provide krealloc()'s __GFP_ZERO guarantees. But if we track the requested size, krealloc() uses that information to do the right thing, so we can zero only the requested size. With red zoning also enabled, any extra size became part of the red zone, so it must not be zeroed and thus we must zero only the requested size. However the current check is imprecise, and will trigger also when only SLAB_RED_ZONE is enabled without SLAB_STORE_USER (which enables tracking the requested size). This means enabling red zoning alone can compromise krealloc()'s __GFP_ZERO contract. Fix this by using slub_debug_orig_size() instead, which is the exact check for whether the requested size is tracked. We don't need to care if red zoning is also enabled or not. Also update and expand the comment accordingly.
CVE-2026-64368
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-2026-64368
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": "9ce67395f5a0cdec6ce152d26bfda13b98b25c01",
"lessThan": "6256899c3a34674bba6076884aedbba49fc695e4",
"versionType": "git"
},
{
"status": "affected",
"version": "9ce67395f5a0cdec6ce152d26bfda13b98b25c01",
"lessThan": "7e706d50fa119eead6376bf0ef973e8d73a96030",
"versionType": "git"
},
{
"status": "affected",
"version": "9ce67395f5a0cdec6ce152d26bfda13b98b25c01",
"lessThan": "2382971aaaef5bf85a651234c64906f59580b8be",
"versionType": "git"
},
{
"status": "affected",
"version": "9ce67395f5a0cdec6ce152d26bfda13b98b25c01",
"lessThan": "0d18ccef142f04433dfb2a0c120cf223d2b8a42c",
"versionType": "git"
},
{
"status": "affected",
"version": "9ce67395f5a0cdec6ce152d26bfda13b98b25c01",
"lessThan": "648927ceb84021a25a0fbd5673740956f318d534",
"versionType": "git"
}
],
"programFiles": [
"mm/slub.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.2"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.2",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.96",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.39",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.4",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"mm/slub.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-64368
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #41017 · Revision 1
- Added to Heist Feed
- Publisher date