net: rtnetlink: zero ifla_vf_broadcast to avoid stack infoleak in rtnl_fill_vfinfo
In the Linux kernel, the following vulnerability has been resolved: net: rtnetlink: zero ifla_vf_broadcast to avoid stack infoleak in rtnl_fill_vfinfo rtnl_fill_vfinfo() declares struct ifla_vf_broadcast on the stack without initialisation: struct ifla_vf_broadcast vf_broadcast; The struct contains a single fixed 32-byte field: /* include/uapi/linux/if_link.h */ struct ifla_vf_broadcast { __u8 broadcast[32]; }; The function then copies dev->broadcast into it using dev->addr_len as the length: memcpy(vf_broadcast.broadcast, dev->broadcast, dev->addr_len); On Ethernet devices (the overwhelming majority of SR-IOV NICs) dev->addr_len is 6, so only the first 6 bytes of broadcast[] are written. The remaining 26 bytes retain whatever was previously on the kernel stack. The full struct is then handed to userspace via: nla_put(skb, IFLA_VF_BROADCAST, sizeof(vf_broadcast), &vf_broadcast) leaking up to 26 bytes of uninitialised kernel stack per VF per RTM_GETLINK request, repeatable. The other vf_* structs in the same function are explicitly zeroed for exactly this reason - see the memset() calls for ivi, vf_vlan_info, node_guid and port_guid a few lines above. vf_broadcast was simply missed when it was added. Reachability: any unprivileged local process can open AF_NETLINK / NETLINK_ROUTE without capabilities and send RTM_GETLINK with an IFLA_EXT_MASK attribute carrying RTEXT_FILTER_VF. The kernel walks each VF and emits IFLA_VF_BROADCAST, leaking 26 bytes of stack per VF per request.
CVE-2026-46132
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-2026-46132
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": "75345f888f700c4ab2448287e35d48c760b202e6",
"lessThan": "14271b401ec6a4bf0d88054106fc2956084717e1",
"versionType": "git"
},
{
"status": "affected",
"version": "75345f888f700c4ab2448287e35d48c760b202e6",
"lessThan": "cccce3190ba4356432b9f22369b56123d3d89f0d",
"versionType": "git"
},
{
"status": "affected",
"version": "75345f888f700c4ab2448287e35d48c760b202e6",
"lessThan": "a44fbb631cba646532f3948636626f81717365a7",
"versionType": "git"
},
{
"status": "affected",
"version": "75345f888f700c4ab2448287e35d48c760b202e6",
"lessThan": "0653c0516234c8258975d268a749115fc0f0ff00",
"versionType": "git"
},
{
"status": "affected",
"version": "75345f888f700c4ab2448287e35d48c760b202e6",
"lessThan": "c5b1b92ab7eff1a6e8c507ddde6fd02fabd0cfa8",
"versionType": "git"
},
{
"status": "affected",
"version": "75345f888f700c4ab2448287e35d48c760b202e6",
"lessThan": "fbe0e6197225e6a83cf113a67a4b425f8de0bcd5",
"versionType": "git"
},
{
"status": "affected",
"version": "75345f888f700c4ab2448287e35d48c760b202e6",
"lessThan": "38bcc21f52246badb3154b6158dcb381d98de011",
"versionType": "git"
},
{
"status": "affected",
"version": "75345f888f700c4ab2448287e35d48c760b202e6",
"lessThan": "4b9e327991815e128ad3af75c3a04630a63ce3e0",
"versionType": "git"
}
],
"programFiles": [
"net/core/rtnetlink.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.3"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.3",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.258",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.209",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.175",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.140",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.88",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.30",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.7",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/core/rtnetlink.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-46132
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #28392 · Revision 1
- Added to Heist Feed
- Publisher date