CVE-2026-64368
mm/slab: do not limit zeroing to orig_size when only red zoning is enabled
Description
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.
INFO
Published Date :
July 25, 2026, 10:17 a.m.
Last Modified :
Aug. 17, 2026, 5:17 a.m.
Remotely Exploit :
Yes !
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to incorporate the fix.
- Ensure SLAB_STORE_USER is enabled when using red zoning.
- Verify zeroing logic with krealloc() and __GFP_ZERO.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-64368.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64368 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-64368
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-64368 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64368 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Changed Affected [{'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-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['mm/slub.c'], 'defaultStatus': 'affected'}] [{'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'}] -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 27, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 25, 2026
Action Type Old Value New Value Added Affected [{'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-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['mm/slub.c'], 'defaultStatus': 'affected'}] Added Description 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. Added Reference https://git.kernel.org/stable/c/0d18ccef142f04433dfb2a0c120cf223d2b8a42c Added Reference https://git.kernel.org/stable/c/2382971aaaef5bf85a651234c64906f59580b8be Added Reference https://git.kernel.org/stable/c/6256899c3a34674bba6076884aedbba49fc695e4 Added Reference https://git.kernel.org/stable/c/648927ceb84021a25a0fbd5673740956f318d534 Added Reference https://git.kernel.org/stable/c/7e706d50fa119eead6376bf0ef973e8d73a96030