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