macvlan: inherit needed_headroom and needed_tailroom from lowerdev
In the Linux kernel, the following vulnerability has been resolved: macvlan: inherit needed_headroom and needed_tailroom from lowerdev macvlan devices inherit hard_header_len from lowerdev during macvlan_init(), but leave needed_headroom and needed_tailroom set to 0. When the underlying lowerdev requires extra headroom or tailroom for headers/trailers (e.g. macsec, ipsec, wireguard, tunnels, or veth with rx headroom), upper layers calculating packet headroom and tailroom fail to reserve sufficient space. This can result in reallocation overhead, skb headroom underflows, or KASAN slab-use-after-free crashes when dev_hard_header() / macvlan_hard_header() prepends header data or when lower devices append tailroom. Fix this by: 1. Inheriting needed_headroom and needed_tailroom from lowerdev in macvlan_init(). 2. Propagating needed_headroom and needed_tailroom updates to attached macvlans in macvlan_device_event() when receiving NETDEV_FEAT_CHANGE events.
CVE-2026-74743
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-2026-74743
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": "b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53",
"lessThan": "c2ef3f134b069c54b9cc95cce1a16c38c4939336",
"versionType": "git"
},
{
"status": "affected",
"version": "b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53",
"lessThan": "7b0eb3e0f363ca79a3af9efd2e87c6258f11da2b",
"versionType": "git"
},
{
"status": "affected",
"version": "b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53",
"lessThan": "8cd90e850e434577bf6774778657d26d6995e53f",
"versionType": "git"
},
{
"status": "affected",
"version": "b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53",
"lessThan": "28afc87bd8da0b3348bbbd834c8a89e83712cf5e",
"versionType": "git"
},
{
"status": "affected",
"version": "b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53",
"lessThan": "8f6a05dbac05725e0786701eb04778c5bdbe4eaa",
"versionType": "git"
},
{
"status": "affected",
"version": "b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53",
"lessThan": "96fa90b74385b7f2b0d97251dd43d5ee6ca44668",
"versionType": "git"
},
{
"status": "affected",
"version": "b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53",
"lessThan": "bc9a00fb78e32bccc39d763bfd13a450705bac5d",
"versionType": "git"
},
{
"status": "affected",
"version": "b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53",
"lessThan": "cef51860becd9700217c81732ca1eb1ea6ed6fe1",
"versionType": "git"
}
],
"programFiles": [
"drivers/net/macvlan.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.23"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.23",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.271",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.222",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.184",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.153",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.105",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.46",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.10",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/net/macvlan.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-74743
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #34289 · Revision 1
- Added to Heist Feed
- Publisher date