macvlan: fix error recovery in macvlan_common_newlink()
In the Linux kernel, the following vulnerability has been resolved: macvlan: fix error recovery in macvlan_common_newlink() valis provided a nice repro to crash the kernel: ip link add p1 type veth peer p2 ip link set address 00:00:00:00:00:20 dev p1 ip link set up dev p1 ip link set up dev p2 ip link add mv0 link p2 type macvlan mode source ip link add invalid% link p2 type macvlan mode source macaddr add 00:00:00:00:00:20 ping -c1 -I p1 1.2.3.4 He also gave a very detailed analysis: The issue is triggered when a new macvlan link is created with MACVLAN_MODE_SOURCE mode and MACVLAN_MACADDR_ADD (or MACVLAN_MACADDR_SET) parameter, lower device already has a macvlan port and register_netdevice() called from macvlan_common_newlink() fails (e.g. because of the invalid link name). In this case macvlan_hash_add_source is called from macvlan_change_sources() / macvlan_common_newlink(): This adds a reference to vlan to the port's vlan_source_hash using macvlan_source_entry. vlan is a pointer to the priv data of the link that is being created. When register_netdevice() fails, the error is returned from macvlan_newlink() to rtnl_newlink_create(): if (ops->newlink) err = ops->newlink(dev, ¶ms, extack); else err = register_netdevice(dev); if (err < 0) { free_netdev(dev); goto out; } and free_netdev() is called, causing a kvfree() on the struct net_device that is still referenced in the source entry attached to the lower device's macvlan port. Now all packets sent on the macvlan port with
CVE-2026-23209
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-2026-23209
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": "aa5fd0fb77486b8a6764ead8627baa14790e4280",
"lessThan": "da5c6b8ae47e414be47e5e04def15b25d5c962dc",
"versionType": "git"
},
{
"status": "affected",
"version": "aa5fd0fb77486b8a6764ead8627baa14790e4280",
"lessThan": "5dae6b36a7cb7a4fcf4121b95e9ca7f96f816c8a",
"versionType": "git"
},
{
"status": "affected",
"version": "aa5fd0fb77486b8a6764ead8627baa14790e4280",
"lessThan": "c43d0e787cbba569ec9d11579ed370b50fab6c9c",
"versionType": "git"
},
{
"status": "affected",
"version": "aa5fd0fb77486b8a6764ead8627baa14790e4280",
"lessThan": "11ba9f0dc865136174cb98834280fb21bbc950c7",
"versionType": "git"
},
{
"status": "affected",
"version": "aa5fd0fb77486b8a6764ead8627baa14790e4280",
"lessThan": "986967a162142710076782d5b93daab93a892980",
"versionType": "git"
},
{
"status": "affected",
"version": "aa5fd0fb77486b8a6764ead8627baa14790e4280",
"lessThan": "cdedcd5aa3f3cb8b7ae0f87ab3a936d0bd583d66",
"versionType": "git"
},
{
"status": "affected",
"version": "aa5fd0fb77486b8a6764ead8627baa14790e4280",
"lessThan": "f8db6475a83649689c087a8f52486fcc53e627e9",
"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": "4.9"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.9",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.250",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.200",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.163",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.124",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.70",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.10",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "6.19",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/net/macvlan.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-23209
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #39819 · Revision 1
- Added to Heist Feed
- Publisher date