mm/damon/vaddr: avoid hw-driven pte updates during damon_hugetlb_mkold()
In the Linux kernel, the following vulnerability has been resolved: mm/damon/vaddr: avoid hw-driven pte updates during damon_hugetlb_mkold() damon_hugetlb_mkold() reads the page table entry into a local variable, unsets the accessed bit in the variable, and updates the page table entry with the updated variable value. If hardware updates the same page table entry in parallel, the hw updates could be lost. For example, hardware-updated dirty bits might be lost. Avoid the parallel updates by clearing the page table entry when reading it together, using huge_ptep_get_and_clear(). If a parallel write to the memory is made after the clearing, the hw will see the page table entry is cleared, trigger page fault and wait until it is handled. The page fault handling will wait for damon_hugetlb_mkold() due to the page table lock. Because hugetlbfs is an in-memory file system and hugetlb pages cannot be reclaimed, no critical issue is expected to my best knowledge. But definitely this is a nasty bug that should be fixed sooner rather than later. The issue was discovered [1] by Sashiko.
CVE-2026-98505
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-2026-98505
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": "49f4203aae06ba9d67b500c90339b262b0a52637",
"lessThan": "7ed1062d154ec2401f2c894fd6858598bb1160b6",
"versionType": "git"
},
{
"status": "affected",
"version": "49f4203aae06ba9d67b500c90339b262b0a52637",
"lessThan": "00457981327c80bcc56e07d4714fe189337a19fa",
"versionType": "git"
},
{
"status": "affected",
"version": "49f4203aae06ba9d67b500c90339b262b0a52637",
"lessThan": "e59cb7eda7c06334a0faf5aa44adb6acf2a1287a",
"versionType": "git"
},
{
"status": "affected",
"version": "49f4203aae06ba9d67b500c90339b262b0a52637",
"lessThan": "6e74ffc9ecf6ec24eee117150da78a1102be74c5",
"versionType": "git"
},
{
"status": "affected",
"version": "49f4203aae06ba9d67b500c90339b262b0a52637",
"lessThan": "39c0ceedd54557bdc1542de08d22b2ed33e534e4",
"versionType": "git"
}
],
"programFiles": [
"mm/damon/vaddr.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.17"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.17",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.112",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.55",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.9",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"mm/damon/vaddr.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98505
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #48887 · Revision 1
- Added to Heist Feed
- Publisher date