esp: downgrade zerocopy managed frags before mutating skb frags
In the Linux kernel, the following vulnerability has been resolved: esp: downgrade zerocopy managed frags before mutating skb frags On the out-of-place output path (esp->inplace == false) ESP rewrites the skb frag array: esp_output_head() appends a trailer frag and esp_output_tail() replaces the frags with a destination page, both referenced with get_page(). When the skb carries zerocopy managed frags (SKBFL_MANAGED_FRAG_REFS) the payload frags are owned by the ubuf and must not be referenced or unreferenced individually, but ESP mutates the frag array without ever downgrading the skb. This breaks the managed-frag invariant two ways: - esp_ssg_unref() walks the source scatterlist and drops a page reference for every frag, including the ubuf-owned payload frags, pushing their refcount below the GUP pin bias while the pages are still pinned, i.e. a use-after-free of the zerocopy pages; - esp_output_tail() installs its destination page as frag 0 with get_page() but leaves SKBFL_MANAGED_FRAG_REFS set, so skb_release_data() takes the skip_unref branch and never drops that reference, leaking the x->xfrag page at packet rate. Fix this the way every other frag-mutating site does (__ip_append_data(), __ip6_append_data(), tcp_sendmsg_locked()) and call skb_zcopy_downgrade_managed() before ESP touches the frag array: it takes a real reference on each existing frag and clears SKBFL_MANAGED_FRAG_REFS, so the per-frag unref in esp_ssg_unref() and the frag release in skb_release_data() are
CVE-2026-98368
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-2026-98368
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": "753f1ca4e1e50248a1b760c9774d6d6b354562cc",
"lessThan": "2359264f377cdbdef2d95868cc8fb572949e48d3",
"versionType": "git"
},
{
"status": "affected",
"version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc",
"lessThan": "69a768c12398cada8528080332c822623fa7064d",
"versionType": "git"
},
{
"status": "affected",
"version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc",
"lessThan": "6508304ac2c8cdafca2f4ab915df8c707893e134",
"versionType": "git"
},
{
"status": "affected",
"version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc",
"lessThan": "6cab554f2c0f28773f712ed3a5479103f42ce844",
"versionType": "git"
},
{
"status": "affected",
"version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc",
"lessThan": "0d0845ee61c5df47cc68bc446501f48f71e8dcc6",
"versionType": "git"
},
{
"status": "affected",
"version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc",
"lessThan": "f89416eb3db151170a6f3c6dfc5239d26cdce4d2",
"versionType": "git"
}
],
"programFiles": [
"net/ipv4/esp4.c",
"net/ipv6/esp6.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.0"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.112",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.54",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.8",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/ipv4/esp4.c",
"net/ipv6/esp6.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98368
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #38446 · Revision 1
- Added to Heist Feed
- Publisher date