CVE-2026-43303 (GCVE-0-2026-43303)
Vulnerability from cvelistv5 – Published: 2026-05-08 13:11 – Updated: 2026-06-19 11:58
VLAI?
Title
mm/page_alloc: clear page->private in free_pages_prepare()
Summary
In the Linux kernel, the following vulnerability has been resolved:
mm/page_alloc: clear page->private in free_pages_prepare()
Several subsystems (slub, shmem, ttm, etc.) use page->private but don't
clear it before freeing pages. When these pages are later allocated as
high-order pages and split via split_page(), tail pages retain stale
page->private values.
This causes a use-after-free in the swap subsystem. The swap code uses
page->private to track swap count continuations, assuming freshly
allocated pages have page->private == 0. When stale values are present,
swap_count_continued() incorrectly assumes the continuation list is valid
and iterates over uninitialized page->lru containing LIST_POISON values,
causing a crash:
KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107]
RIP: 0010:__do_sys_swapoff+0x1151/0x1860
Fix this by clearing page->private in free_pages_prepare(), ensuring all
freed pages have clean state regardless of previous use.
Severity ?
7.8 (High)
Assigner
References
Impacted products
| Vendor | Product | Version | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux |
Affected:
3b8000ae185cb068adbda5f966a3835053c85fd4 , < e7790ab165713b79b1617ce659742ceb3a859d05
(git)
Affected: 3b8000ae185cb068adbda5f966a3835053c85fd4 , < 3edb8ebbf79b9016040e8f3421d723ae3d542b32 (git) Affected: 3b8000ae185cb068adbda5f966a3835053c85fd4 , < f9719e32a67b4b00b3c9b133e8b5ffa72a26b67b (git) Affected: 3b8000ae185cb068adbda5f966a3835053c85fd4 , < 23b82b7a26182ad840ae67d390d7ec9771e8c00f (git) Affected: 3b8000ae185cb068adbda5f966a3835053c85fd4 , < d757c793853ec5483eb41ec2942c300b8fa720fb (git) Affected: 3b8000ae185cb068adbda5f966a3835053c85fd4 , < ac1ea219590c09572ed5992dc233bbf7bb70fef9 (git) |
|||||||
|
|||||||||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"mm/page_alloc.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "e7790ab165713b79b1617ce659742ceb3a859d05",
"status": "affected",
"version": "3b8000ae185cb068adbda5f966a3835053c85fd4",
"versionType": "git"
},
{
"lessThan": "3edb8ebbf79b9016040e8f3421d723ae3d542b32",
"status": "affected",
"version": "3b8000ae185cb068adbda5f966a3835053c85fd4",
"versionType": "git"
},
{
"lessThan": "f9719e32a67b4b00b3c9b133e8b5ffa72a26b67b",
"status": "affected",
"version": "3b8000ae185cb068adbda5f966a3835053c85fd4",
"versionType": "git"
},
{
"lessThan": "23b82b7a26182ad840ae67d390d7ec9771e8c00f",
"status": "affected",
"version": "3b8000ae185cb068adbda5f966a3835053c85fd4",
"versionType": "git"
},
{
"lessThan": "d757c793853ec5483eb41ec2942c300b8fa720fb",
"status": "affected",
"version": "3b8000ae185cb068adbda5f966a3835053c85fd4",
"versionType": "git"
},
{
"lessThan": "ac1ea219590c09572ed5992dc233bbf7bb70fef9",
"status": "affected",
"version": "3b8000ae185cb068adbda5f966a3835053c85fd4",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"mm/page_alloc.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.18"
},
{
"lessThan": "5.18",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.176",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.143",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.93",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.16",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.19.*",
"status": "unaffected",
"version": "6.19.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.176",
"versionStartIncluding": "5.18",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.143",
"versionStartIncluding": "5.18",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.93",
"versionStartIncluding": "5.18",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.16",
"versionStartIncluding": "5.18",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.19.6",
"versionStartIncluding": "5.18",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.0",
"versionStartIncluding": "5.18",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_alloc: clear page-\u003eprivate in free_pages_prepare()\n\nSeveral subsystems (slub, shmem, ttm, etc.) use page-\u003eprivate but don\u0027t\nclear it before freeing pages. When these pages are later allocated as\nhigh-order pages and split via split_page(), tail pages retain stale\npage-\u003eprivate values.\n\nThis causes a use-after-free in the swap subsystem. The swap code uses\npage-\u003eprivate to track swap count continuations, assuming freshly\nallocated pages have page-\u003eprivate == 0. When stale values are present,\nswap_count_continued() incorrectly assumes the continuation list is valid\nand iterates over uninitialized page-\u003elru containing LIST_POISON values,\ncausing a crash:\n\n KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107]\n RIP: 0010:__do_sys_swapoff+0x1151/0x1860\n\nFix this by clearing page-\u003eprivate in free_pages_prepare(), ensuring all\nfreed pages have clean state regardless of previous use."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-06-19T11:58:25.269Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/e7790ab165713b79b1617ce659742ceb3a859d05"
},
{
"url": "https://git.kernel.org/stable/c/3edb8ebbf79b9016040e8f3421d723ae3d542b32"
},
{
"url": "https://git.kernel.org/stable/c/f9719e32a67b4b00b3c9b133e8b5ffa72a26b67b"
},
{
"url": "https://git.kernel.org/stable/c/23b82b7a26182ad840ae67d390d7ec9771e8c00f"
},
{
"url": "https://git.kernel.org/stable/c/d757c793853ec5483eb41ec2942c300b8fa720fb"
},
{
"url": "https://git.kernel.org/stable/c/ac1ea219590c09572ed5992dc233bbf7bb70fef9"
}
],
"title": "mm/page_alloc: clear page-\u003eprivate in free_pages_prepare()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-43303",
"datePublished": "2026-05-08T13:11:23.561Z",
"dateReserved": "2026-05-01T14:12:56.000Z",
"dateUpdated": "2026-06-19T11:58:25.269Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
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.
Loading…
Loading…