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macsec: don't read an unset MAC header in macsec_encrypt()

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: macsec: don't read an unset MAC header in macsec_encrypt() macsec_encrypt() reads the Ethernet header via eth_hdr(skb) (skb->head + skb->mac_header) to memmove() the 12 source/destination MAC bytes forward and make room for the SecTAG. On the AF_PACKET SOCK_RAW + PACKET_QDISC_BYPASS transmit path the skb reaches the macsec ndo_start_xmit() with the MAC header unset, so eth_hdr(skb) resolves to skb->head + (u16)~0 and the read is out of bounds: a 12-byte heap over-read that is also emitted on the wire as the frame's outer source/destination MAC. KASAN reports a slab-out-of-bounds read in macsec_start_xmit() on 6.0; on current mainline a CONFIG_DEBUG_NET build flags it as an unset mac header in skb_mac_header(). On the TX path the L2 header is at skb->data, so use skb_eth_hdr(), added by commit 96cc4b69581d ("macvlan: do not assume mac_header is set in macvlan_broadcast()") for exactly this purpose.

Announced Source revision 1
Original source ↗

CVE-2026-72019

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-2026-72019

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": "c09440f7dcb304002dfced8c0fea289eb25f2da0",
        "lessThan": "b6cec6187b8632423cd99a94fd5e5ba165fa2a33",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c09440f7dcb304002dfced8c0fea289eb25f2da0",
        "lessThan": "3adea1b1c04b57e08a5c12a1f42483760581ce61",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c09440f7dcb304002dfced8c0fea289eb25f2da0",
        "lessThan": "dc9ffa1905e72f026d080880a2e4cfc42aa91000",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c09440f7dcb304002dfced8c0fea289eb25f2da0",
        "lessThan": "f21fa533a3ed15ada74106aac4b9ddd078fc6b7a",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c09440f7dcb304002dfced8c0fea289eb25f2da0",
        "lessThan": "e17a42199824973cd8212e95b21ffadf4114a21b",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c09440f7dcb304002dfced8c0fea289eb25f2da0",
        "lessThan": "2cf10d042562283ff4ae97c02d0993d4f1b5ea29",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c09440f7dcb304002dfced8c0fea289eb25f2da0",
        "lessThan": "c39087ad0b97fc11a3b058dfc8db9fd370762cb9",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c09440f7dcb304002dfced8c0fea289eb25f2da0",
        "lessThan": "f5089008f90c0a7c5520dff3934e0af00adf322d",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "drivers/net/macsec.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "4.6"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "4.6",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.10.265",
        "versionType": "semver",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.216",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.178",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.145",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.97",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.40",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.1.5",
        "versionType": "semver",
        "lessThanOrEqual": "7.1.*"
      },
      {
        "status": "unaffected",
        "version": "7.2",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "drivers/net/macsec.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-72019

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#41836 · Revision 1
Added to Heist Feed
Publisher date
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