CVE-2026-93105 (GCVE-0-2026-93105)
Vulnerability from cvelistv5 – Published: 2026-09-17 16:11 – Updated: 2026-09-17 16:11
VLAI
EPSS
VEX
Title
esp: do not unref managed frag pages in esp_ssg_unref()
Summary
In the Linux kernel, the following vulnerability has been resolved:
esp: do not unref managed frag pages in esp_ssg_unref()
esp_ssg_unref() releases the page references held on the source
scatterlist after the AEAD operation completes. It calls
skb_page_unref() on every frag page for an out-of-place transform
(req->src != req->dst), and in the error path of esp_output_tail()
(already_unref == true) on the request's own scatterlist.
This is wrong when the skb carries managed frags
(SKBFL_MANAGED_FRAG_REFS). Managed frags are owned by a zerocopy ubuf
and the skb does not hold a per-frag page reference; io_uring SEND_ZC
with a registered buffer attaches the bvec pages this way via
io_sg_from_iter(). The rest of the stack honours this invariant:
skb_release_data() skips the per-frag unref when SKBFL_MANAGED_FRAG_REFS
is set, and skb_zcopy_managed() is the guard used at the other unref
sites.
esp_ssg_unref() is missing that guard, so for a managed-frag skb it
drops a page reference the skb never acquired. This can underflow the
page reference count and free a page that is still in use.
Guard the function with skb_zcopy_managed() so both unref paths are
skipped for managed-frag skbs, matching skb_release_data().
Severity
No CVSS data available.
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
cac2661c53f35cbe651bef9b07026a5a05ab8ce0 , < 26b6b14c7a0368e317a1e9fb5144ebe6f8d495cf
(git)
Affected: cac2661c53f35cbe651bef9b07026a5a05ab8ce0 , < 21697720ff43b8dfa25b8e8d9ca7f56f4597fc80 (git) |
guessed | |
| Linux | Linux |
Affected:
4.11
Unaffected: 0 , < 4.11 (semver) Unaffected: 7.2.6 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix) |
guessed |
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"product": "Linux",
"programFiles": [
"net/ipv4/esp4.c",
"net/ipv6/esp6.c"
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},
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nesp: do not unref managed frag pages in esp_ssg_unref()\n\nesp_ssg_unref() releases the page references held on the source\nscatterlist after the AEAD operation completes. It calls\nskb_page_unref() on every frag page for an out-of-place transform\n(req-\u003esrc != req-\u003edst), and in the error path of esp_output_tail()\n(already_unref == true) on the request\u0027s own scatterlist.\n\nThis is wrong when the skb carries managed frags\n(SKBFL_MANAGED_FRAG_REFS). Managed frags are owned by a zerocopy ubuf\nand the skb does not hold a per-frag page reference; io_uring SEND_ZC\nwith a registered buffer attaches the bvec pages this way via\nio_sg_from_iter(). The rest of the stack honours this invariant:\nskb_release_data() skips the per-frag unref when SKBFL_MANAGED_FRAG_REFS\nis set, and skb_zcopy_managed() is the guard used at the other unref\nsites.\n\nesp_ssg_unref() is missing that guard, so for a managed-frag skb it\ndrops a page reference the skb never acquired. This can underflow the\npage reference count and free a page that is still in use.\n\nGuard the function with skb_zcopy_managed() so both unref paths are\nskipped for managed-frag skbs, matching skb_release_data()."
}
],
"providerMetadata": {
"dateUpdated": "2026-09-17T16:11:16.442Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/26b6b14c7a0368e317a1e9fb5144ebe6f8d495cf"
},
{
"url": "https://git.kernel.org/stable/c/21697720ff43b8dfa25b8e8d9ca7f56f4597fc80"
}
],
"title": "esp: do not unref managed frag pages in esp_ssg_unref()",
"x_generator": {
"engine": "bippy-1.2.0"
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"cveMetadata": {
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"assignerShortName": "Linux",
"cveId": "CVE-2026-93105",
"datePublished": "2026-09-17T16:11:16.442Z",
"dateReserved": "2026-09-17T16:02:15.085Z",
"dateUpdated": "2026-09-17T16:11:16.442Z",
"state": "PUBLISHED"
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"dataVersion": "5.2",
"vulnerability-lookup:meta": {
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"affected": [
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"product": "Linux",
"programFiles": [
"net/ipv4/esp4.c",
"net/ipv6/esp6.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
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{
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
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},
{
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"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
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"status": "unaffected",
"version": "7.2.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc1",
"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\nesp: do not unref managed frag pages in esp_ssg_unref()\n\nesp_ssg_unref() releases the page references held on the source\nscatterlist after the AEAD operation completes. It calls\nskb_page_unref() on every frag page for an out-of-place transform\n(req-\u003esrc != req-\u003edst), and in the error path of esp_output_tail()\n(already_unref == true) on the request\u0027s own scatterlist.\n\nThis is wrong when the skb carries managed frags\n(SKBFL_MANAGED_FRAG_REFS). Managed frags are owned by a zerocopy ubuf\nand the skb does not hold a per-frag page reference; io_uring SEND_ZC\nwith a registered buffer attaches the bvec pages this way via\nio_sg_from_iter(). The rest of the stack honours this invariant:\nskb_release_data() skips the per-frag unref when SKBFL_MANAGED_FRAG_REFS\nis set, and skb_zcopy_managed() is the guard used at the other unref\nsites.\n\nesp_ssg_unref() is missing that guard, so for a managed-frag skb it\ndrops a page reference the skb never acquired. This can underflow the\npage reference count and free a page that is still in use.\n\nGuard the function with skb_zcopy_managed() so both unref paths are\nskipped for managed-frag skbs, matching skb_release_data()."
}
],
"id": "CVE-2026-93105",
"lastModified": "2026-09-17T17:18:04.847",
"metrics": {},
"published": "2026-09-17T17:18:04.847",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/21697720ff43b8dfa25b8e8d9ca7f56f4597fc80"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/26b6b14c7a0368e317a1e9fb5144ebe6f8d495cf"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
},
"suse_vex": {
"aggregate_severity": "not set",
"current_release_date": "2026-09-18T00:11:59Z",
"cve": "CVE-2026-93105",
"id": "CVE-2026-93105",
"initial_release_date": "2026-09-18T00:11:59Z",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2026-93105",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-93105.json",
"version": "2"
}
}
}
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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.
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- Published Proof of Concept: A public proof of concept is available for this vulnerability.
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- 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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