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net: skmsg: preserve sg.copy across SG transforms

Type: advisorySource: Official CVE List1 source record

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.

Announced Source revision 1
Original source ↗

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
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Publisher date
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