CVE-2026-80719 (GCVE-0-2026-80719)
Vulnerability from cvelistv5 – Published: 2026-08-28 06:53 – Updated: 2026-08-28 06:53
VLAI
EPSS
VEX
Title
mm: mglru: fix stale batch updates after memcg reparenting
Summary
In the Linux kernel, the following vulnerability has been resolved:
mm: mglru: fix stale batch updates after memcg reparenting
The mglru page table walker batches per-generation size deltas in
walk->nr_pages while walking page tables without holding the lruvec lock.
The reset_batch_size() later folds those deltas into walk->lruvec under
the lruvec lock.
The page table walker can run concurrently with the memcg reparenting path
as follows:
CPU0 CPU1
==== ====
walk_mm
--> walk_page_range
--> update_batch_size
--> walk->nr_pages += delta
mem_cgroup_css_offline
--> memcg_reparent_objcgs
--> lock lruvec
lru_gen_reparent_memcg
--> reparent child folios to parent
unlock lruvec
lock lruvec
reset_batch_size
--> child lrugen->nr_pages += delta
This will trigger the following warning in lru_gen_exit_memcg():
VM_WARN_ON_ONCE(memchr_inv(lruvec->lrugen.nr_pages, 0,
sizeof(lruvec->lrugen.nr_pages)));
And the user-visible impact of underestimated nr_pages in MGLRU was
premature OOMs because MGLRU does not try to reclaim memory when nr_pages
reaches zero, but there are still more pages.
To fix it, make reset_batch_size() check CSS_DYING under RCU before
flushing the pending batch. A non-dying memcg keeps the original lruvec
stable against RCU-delayed offlining; a dying memcg redirects the deltas
to the first non-dying ancestor.
Severity
No CVSS data available.
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
f304652609eae3814b0e9d11c75c0e0cb62da31f , < fceb6b7f3ddec6ea9fc11577f4cf1b2da73a3101
(git)
Affected: f304652609eae3814b0e9d11c75c0e0cb62da31f , < de4660898b7aa7e03d3b120a6bfa6b26211e4e77 (git) |
guessed | |
| Linux | Linux |
Affected:
7.1
Unaffected: 0 , < 7.1 (semver) Unaffected: 7.1.8 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix) |
guessed |
{
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"programFiles": [
"include/linux/memcontrol.h",
"mm/vmscan.c"
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"versionType": "git"
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"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
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"cpeApplicability": [
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"nodes": [
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"vulnerable": true
},
{
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"descriptions": [
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm: mglru: fix stale batch updates after memcg reparenting\n\nThe mglru page table walker batches per-generation size deltas in\nwalk-\u003enr_pages while walking page tables without holding the lruvec lock. \nThe reset_batch_size() later folds those deltas into walk-\u003elruvec under\nthe lruvec lock.\n\nThe page table walker can run concurrently with the memcg reparenting path\nas follows:\n\nCPU0 CPU1\n==== ====\n\nwalk_mm\n--\u003e walk_page_range\n --\u003e update_batch_size\n --\u003e walk-\u003enr_pages += delta\n\n mem_cgroup_css_offline\n --\u003e memcg_reparent_objcgs\n --\u003e lock lruvec\n lru_gen_reparent_memcg\n --\u003e reparent child folios to parent\n unlock lruvec\n\n lock lruvec\n reset_batch_size\n --\u003e child lrugen-\u003enr_pages += delta\n\nThis will trigger the following warning in lru_gen_exit_memcg():\n\n\tVM_WARN_ON_ONCE(memchr_inv(lruvec-\u003elrugen.nr_pages, 0,\n\t\t\t\t sizeof(lruvec-\u003elrugen.nr_pages)));\n\nAnd the user-visible impact of underestimated nr_pages in MGLRU was\npremature OOMs because MGLRU does not try to reclaim memory when nr_pages\nreaches zero, but there are still more pages.\n\nTo fix it, make reset_batch_size() check CSS_DYING under RCU before\nflushing the pending batch. A non-dying memcg keeps the original lruvec\nstable against RCU-delayed offlining; a dying memcg redirects the deltas\nto the first non-dying ancestor."
}
],
"providerMetadata": {
"dateUpdated": "2026-08-28T06:53:16.087Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/fceb6b7f3ddec6ea9fc11577f4cf1b2da73a3101"
},
{
"url": "https://git.kernel.org/stable/c/de4660898b7aa7e03d3b120a6bfa6b26211e4e77"
}
],
"title": "mm: mglru: fix stale batch updates after memcg reparenting",
"x_generator": {
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}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-80719",
"datePublished": "2026-08-28T06:53:16.087Z",
"dateReserved": "2026-08-26T14:34:25.788Z",
"dateUpdated": "2026-08-28T06:53:16.087Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2026-80719\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-28T08:16:57.720\",\"lastModified\":\"2026-08-28T08:16:57.720\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nmm: mglru: fix stale batch updates after memcg reparenting\\n\\nThe mglru page table walker batches per-generation size deltas in\\nwalk-\u003enr_pages while walking page tables without holding the lruvec lock. \\nThe reset_batch_size() later folds those deltas into walk-\u003elruvec under\\nthe lruvec lock.\\n\\nThe page table walker can run concurrently with the memcg reparenting path\\nas follows:\\n\\nCPU0 CPU1\\n==== ====\\n\\nwalk_mm\\n--\u003e walk_page_range\\n --\u003e update_batch_size\\n --\u003e walk-\u003enr_pages += delta\\n\\n mem_cgroup_css_offline\\n --\u003e memcg_reparent_objcgs\\n --\u003e lock lruvec\\n lru_gen_reparent_memcg\\n --\u003e reparent child folios to parent\\n unlock lruvec\\n\\n lock lruvec\\n reset_batch_size\\n --\u003e child lrugen-\u003enr_pages += delta\\n\\nThis will trigger the following warning in lru_gen_exit_memcg():\\n\\n\\tVM_WARN_ON_ONCE(memchr_inv(lruvec-\u003elrugen.nr_pages, 0,\\n\\t\\t\\t\\t sizeof(lruvec-\u003elrugen.nr_pages)));\\n\\nAnd the user-visible impact of underestimated nr_pages in MGLRU was\\npremature OOMs because MGLRU does not try to reclaim memory when nr_pages\\nreaches zero, but there are still more pages.\\n\\nTo fix it, make reset_batch_size() check CSS_DYING under RCU before\\nflushing the pending batch. A non-dying memcg keeps the original lruvec\\nstable against RCU-delayed offlining; a dying memcg redirects the deltas\\nto the first non-dying ancestor.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"include/linux/memcontrol.h\",\"mm/vmscan.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"f304652609eae3814b0e9d11c75c0e0cb62da31f\",\"lessThan\":\"fceb6b7f3ddec6ea9fc11577f4cf1b2da73a3101\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f304652609eae3814b0e9d11c75c0e0cb62da31f\",\"lessThan\":\"de4660898b7aa7e03d3b120a6bfa6b26211e4e77\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"include/linux/memcontrol.h\",\"mm/vmscan.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"7.1\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"7.1\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.8\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/de4660898b7aa7e03d3b120a6bfa6b26211e4e77\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/fceb6b7f3ddec6ea9fc11577f4cf1b2da73a3101\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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