CVE-2025-68262 (GCVE-0-2025-68262)
Vulnerability from cvelistv5 – Published: 2025-12-16 14:45 – Updated: 2026-05-11 21:49
VLAI
EPSS
VEX
Title
crypto: zstd - fix double-free in per-CPU stream cleanup
Summary
In the Linux kernel, the following vulnerability has been resolved:
crypto: zstd - fix double-free in per-CPU stream cleanup
The crypto/zstd module has a double-free bug that occurs when multiple
tfms are allocated and freed.
The issue happens because zstd_streams (per-CPU contexts) are freed in
zstd_exit() during every tfm destruction, rather than being managed at
the module level. When multiple tfms exist, each tfm exit attempts to
free the same shared per-CPU streams, resulting in a double-free.
This leads to a stack trace similar to:
BUG: Bad page state in process kworker/u16:1 pfn:106fd93
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x106fd93
flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff)
page_type: 0xffffffff()
raw: 0017ffffc0000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: nonzero entire_mapcount
Modules linked in: ...
CPU: 3 UID: 0 PID: 2506 Comm: kworker/u16:1 Kdump: loaded Tainted: G B
Hardware name: ...
Workqueue: btrfs-delalloc btrfs_work_helper
Call Trace:
<TASK>
dump_stack_lvl+0x5d/0x80
bad_page+0x71/0xd0
free_unref_page_prepare+0x24e/0x490
free_unref_page+0x60/0x170
crypto_acomp_free_streams+0x5d/0xc0
crypto_acomp_exit_tfm+0x23/0x50
crypto_destroy_tfm+0x60/0xc0
...
Change the lifecycle management of zstd_streams to free the streams only
once during module cleanup.
Severity
No CVSS data available.
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
f5ad93ffb54119a8dc5e18f070624d4ead586969 , < dc0f4509b0ed5d82bef78e058db0ac4df04d0695
(git)
Affected: f5ad93ffb54119a8dc5e18f070624d4ead586969 , < e983feaa79de1e46c9087fb9f02fedb0e5397ce6 (git) Affected: f5ad93ffb54119a8dc5e18f070624d4ead586969 , < 48bc9da3c97c15f1ea24934bcb3b736acd30163d (git) |
guessed | |
| Linux | Linux |
Affected:
6.17
Unaffected: 0 , < 6.17 (semver) Unaffected: 6.17.12 , ≤ 6.17.* (semver) Unaffected: 6.18.1 , ≤ 6.18.* (semver) Unaffected: 6.19 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
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"affected": [
{
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"product": "Linux",
"programFiles": [
"crypto/zstd.c"
],
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"versionType": "git"
},
{
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{
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},
{
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"version": "0",
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"status": "unaffected",
"version": "6.18.1",
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{
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"status": "unaffected",
"version": "6.19",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
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"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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"versionStartIncluding": "6.17",
"vulnerable": true
},
{
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},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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"versionStartIncluding": "6.17",
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}
],
"negate": false,
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}
]
}
],
"descriptions": [
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"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: zstd - fix double-free in per-CPU stream cleanup\n\nThe crypto/zstd module has a double-free bug that occurs when multiple\ntfms are allocated and freed.\n\nThe issue happens because zstd_streams (per-CPU contexts) are freed in\nzstd_exit() during every tfm destruction, rather than being managed at\nthe module level. When multiple tfms exist, each tfm exit attempts to\nfree the same shared per-CPU streams, resulting in a double-free.\n\nThis leads to a stack trace similar to:\n\n BUG: Bad page state in process kworker/u16:1 pfn:106fd93\n page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x106fd93\n flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff)\n page_type: 0xffffffff()\n raw: 0017ffffc0000000 dead000000000100 dead000000000122 0000000000000000\n raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000\n page dumped because: nonzero entire_mapcount\n Modules linked in: ...\n CPU: 3 UID: 0 PID: 2506 Comm: kworker/u16:1 Kdump: loaded Tainted: G B\n Hardware name: ...\n Workqueue: btrfs-delalloc btrfs_work_helper\n Call Trace:\n \u003cTASK\u003e\n dump_stack_lvl+0x5d/0x80\n bad_page+0x71/0xd0\n free_unref_page_prepare+0x24e/0x490\n free_unref_page+0x60/0x170\n crypto_acomp_free_streams+0x5d/0xc0\n crypto_acomp_exit_tfm+0x23/0x50\n crypto_destroy_tfm+0x60/0xc0\n ...\n\nChange the lifecycle management of zstd_streams to free the streams only\nonce during module cleanup."
}
],
"providerMetadata": {
"dateUpdated": "2026-05-11T21:49:58.343Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/dc0f4509b0ed5d82bef78e058db0ac4df04d0695"
},
{
"url": "https://git.kernel.org/stable/c/e983feaa79de1e46c9087fb9f02fedb0e5397ce6"
},
{
"url": "https://git.kernel.org/stable/c/48bc9da3c97c15f1ea24934bcb3b736acd30163d"
}
],
"title": "crypto: zstd - fix double-free in per-CPU stream cleanup",
"x_generator": {
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}
}
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"cveMetadata": {
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"assignerShortName": "Linux",
"cveId": "CVE-2025-68262",
"datePublished": "2025-12-16T14:45:04.198Z",
"dateReserved": "2025-12-16T13:41:40.267Z",
"dateUpdated": "2026-05-11T21:49:58.343Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2025-68262",
"date": "2026-09-30",
"epss": "0.00184",
"percentile": "0.07156"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
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"versionType": "git"
},
{
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"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.17"
},
{
"lessThan": "6.17",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
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"version": "6.17.12",
"versionType": "semver"
},
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"version": "6.18.1",
"versionType": "semver"
},
{
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"version": "6.19",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: zstd - fix double-free in per-CPU stream cleanup\n\nThe crypto/zstd module has a double-free bug that occurs when multiple\ntfms are allocated and freed.\n\nThe issue happens because zstd_streams (per-CPU contexts) are freed in\nzstd_exit() during every tfm destruction, rather than being managed at\nthe module level. When multiple tfms exist, each tfm exit attempts to\nfree the same shared per-CPU streams, resulting in a double-free.\n\nThis leads to a stack trace similar to:\n\n BUG: Bad page state in process kworker/u16:1 pfn:106fd93\n page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x106fd93\n flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff)\n page_type: 0xffffffff()\n raw: 0017ffffc0000000 dead000000000100 dead000000000122 0000000000000000\n raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000\n page dumped because: nonzero entire_mapcount\n Modules linked in: ...\n CPU: 3 UID: 0 PID: 2506 Comm: kworker/u16:1 Kdump: loaded Tainted: G B\n Hardware name: ...\n Workqueue: btrfs-delalloc btrfs_work_helper\n Call Trace:\n \u003cTASK\u003e\n dump_stack_lvl+0x5d/0x80\n bad_page+0x71/0xd0\n free_unref_page_prepare+0x24e/0x490\n free_unref_page+0x60/0x170\n crypto_acomp_free_streams+0x5d/0xc0\n crypto_acomp_exit_tfm+0x23/0x50\n crypto_destroy_tfm+0x60/0xc0\n ...\n\nChange the lifecycle management of zstd_streams to free the streams only\nonce during module cleanup."
}
],
"id": "CVE-2025-68262",
"lastModified": "2026-06-17T09:58:49.730",
"metrics": {},
"published": "2025-12-16T15:15:55.697",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/48bc9da3c97c15f1ea24934bcb3b736acd30163d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/dc0f4509b0ed5d82bef78e058db0ac4df04d0695"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/e983feaa79de1e46c9087fb9f02fedb0e5397ce6"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Deferred"
}
},
"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2026-09-01T12:46:45+00:00",
"cve": "CVE-2025-68262",
"id": "CVE-2025-68262",
"initial_release_date": "2025-12-16T14:45:04.198000+00:00",
"product_status:known_affected": "277",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: crypto: zstd - fix double-free in per-CPU stream cleanup",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-68262.json",
"version": "3"
},
"suse_vex": {
"aggregate_severity": "moderate",
"current_release_date": "2026-08-30T01:43:07Z",
"cve": "CVE-2025-68262",
"id": "CVE-2025-68262",
"initial_release_date": "2025-12-17T00:24:06Z",
"product_status:known_not_affected": "525",
"product_status:recommended": "6",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2025-68262",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2025-68262.json",
"version": "10"
}
}
}
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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.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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