futex: Avoid private hash use-after-free on final put
In the Linux kernel, the following vulnerability has been resolved: futex: Avoid private hash use-after-free on final put futex_private_hash_put() drops the reference to fph before evaluating fph->mm for wake_up_var(). futex_ref_put() enables preemption again before returning. If that put drops the final reference and the task is preempted, another task can pivot to the replacement hash and free the old hash after an RCU grace period. The first task then reads fph->mm from the freed allocation when it resumes. KASAN reports a slab-use-after-free in futex_private_hash_put(), with the read at offset 24 in a freed kmalloc-512 allocation. The allocation and free stacks point to futex_hash_allocate() and the RCU free path, respectively. Load the mm pointer while the fph reference is still held and pass the saved value to wake_up_var(). wake_up_var() uses the pointer as a waitqueue key and does not dereference the mm through it.
CVE-2026-80758
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-2026-80758
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": "bd54df5ea7cadac520e346d5f0fe5d58e635b6ba",
"lessThan": "dba60d26e9dda3e157ad6b0934d4232f6c6904ee",
"versionType": "git"
},
{
"status": "affected",
"version": "bd54df5ea7cadac520e346d5f0fe5d58e635b6ba",
"lessThan": "12cd315a7b6a7d7db3f69d98bfe3909275e9451d",
"versionType": "git"
},
{
"status": "affected",
"version": "bd54df5ea7cadac520e346d5f0fe5d58e635b6ba",
"lessThan": "25408c62ed4ebcd491d0e9e4b4a5b512547512e4",
"versionType": "git"
},
{
"status": "affected",
"version": "bd54df5ea7cadac520e346d5f0fe5d58e635b6ba",
"lessThan": "1c7efabfbaf796f11000a46094a69955a01ec6cc",
"versionType": "git"
}
],
"programFiles": [
"kernel/futex/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": "6.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.47",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.11",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2.1",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"kernel/futex/core.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-80758
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #34778 · Revision 1
- Added to Heist Feed
- Publisher date