net: skmsg: preserve sg.copy across SG transforms
In the Linux kernel, the following vulnerability has been resolved: net: skmsg: preserve sg.copy across SG transforms The sk_msg sg.copy bitmap is part of the scatterlist entry ownership state. A set bit tells sk_msg_compute_data_pointers() not to expose the entry through writable BPF ctx->data. This protects entries backed by pages that are not private to the sk_msg, such as splice-backed file page-cache pages. Several sk_msg transform paths move, copy, split, or compact msg->sg.data[] entries without moving the matching sg.copy bit. This can make an externally backed entry arrive at a new slot with a clear copy bit. A later SK_MSG verdict can then expose sg_virt(sge) as writable ctx->data and BPF stores can modify the original page cache. Keep sg.copy synchronized with sg.data[] whenever entries are transferred, shifted, split, or copied into a new sk_msg. Clear the bit when an entry is replaced by a newly allocated private page or freed. This covers the BPF pull/push/pop helpers, sk_msg_shift_left/right(), sk_msg_xfer(), and tls_split_open_record(), including the partial tail entry created during TLS open-record splitting.
CVE-2026-63830
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-2026-63830
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": "d3b18ad31f93d0b6bae105c679018a1ba7daa9ca",
"lessThan": "f126eed589eec6f201405abbc398844042ef6d57",
"versionType": "git"
},
{
"status": "affected",
"version": "d3b18ad31f93d0b6bae105c679018a1ba7daa9ca",
"lessThan": "31a110642b5fb5e61940cbcfb503445ac4f28017",
"versionType": "git"
},
{
"status": "affected",
"version": "d3b18ad31f93d0b6bae105c679018a1ba7daa9ca",
"lessThan": "9bb86d8184b37503816150c4a6ad3c17dfdbe827",
"versionType": "git"
},
{
"status": "affected",
"version": "d3b18ad31f93d0b6bae105c679018a1ba7daa9ca",
"lessThan": "0eb4c16c4adb262763bda870a8ed38a1a9dec7ec",
"versionType": "git"
},
{
"status": "affected",
"version": "d3b18ad31f93d0b6bae105c679018a1ba7daa9ca",
"lessThan": "d22cc92bc41290e5783a72375e0843d9435f6001",
"versionType": "git"
},
{
"status": "affected",
"version": "d3b18ad31f93d0b6bae105c679018a1ba7daa9ca",
"lessThan": "1acdd14c0990dd1cd4b6534f00366d2e6dfce05f",
"versionType": "git"
},
{
"status": "affected",
"version": "d3b18ad31f93d0b6bae105c679018a1ba7daa9ca",
"lessThan": "21ed9540a8e1906dfcbc1bb82ba9b4de4fa4bd6d",
"versionType": "git"
},
{
"status": "affected",
"version": "d3b18ad31f93d0b6bae105c679018a1ba7daa9ca",
"lessThan": "406e8a651a7b854c41fecd5117bb282b3a6c2c6b",
"versionType": "git"
}
],
"programFiles": [
"include/linux/skmsg.h",
"net/core/filter.c",
"net/core/skmsg.c",
"net/tls/tls_sw.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.20"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.20",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.177",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.144",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.95",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.38",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.3",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/linux/skmsg.h",
"net/core/filter.c",
"net/core/skmsg.c",
"net/tls/tls_sw.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-63830
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #40841 · Revision 1
- Added to Heist Feed
- Publisher date