ip: orphan prefetched skbs before multicast forwarding
In the Linux kernel, the following vulnerability has been resolved: ip: orphan prefetched skbs before multicast forwarding IPv4 and IPv6 input preserve an skb->sk association installed by bpf_sk_assign() so that local delivery can use the selected socket under RCU. Both address families can also prefetch a socket in UDP early demux. In both paths (BPF and UDP early demux) a reference is not guaranteed to be held on the socket. When a multicast packet is not locally deliverable, IPv6 hands the original skb to ip6_mr_input(). IPv4's ip_mr_input() similarly keeps the original skb when local delivery is not needed. Either path can put the skb on an unresolved multicast route queue or forward it after the receive-side RCU section ends. After the prefetched socket is destroyed, a later skb free invokes sock_pfree() and dereferences the stale skb->sk. Orphan the skb before each non-local multicast forwarding path. Local delivery retains the original skb; the existing skb_clone() calls provide multicast forwarding with a socket-free clone.
CVE-2026-89564
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-2026-89564
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": "cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449",
"lessThan": "882212d317a7c16ab70d20656f6b1c42abada9f6",
"versionType": "git"
},
{
"status": "affected",
"version": "cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449",
"lessThan": "e62aef7d6a5b27569bf540bbe11a9482117ff588",
"versionType": "git"
},
{
"status": "affected",
"version": "cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449",
"lessThan": "a8af6fbac895f057c4b8ff8a2e3fb4c5827fe4ce",
"versionType": "git"
},
{
"status": "affected",
"version": "cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449",
"lessThan": "f1281d4b99089fbaf0d3579bba62a814ebb4de4d",
"versionType": "git"
},
{
"status": "affected",
"version": "cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449",
"lessThan": "e36ce6e78fe3fc3c071a26750783b7ba081ce10d",
"versionType": "git"
}
],
"programFiles": [
"net/ipv4/ipmr.c",
"net/ipv6/ip6_input.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.7"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.7",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/ipv4/ipmr.c",
"net/ipv6/ip6_input.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89564
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #46680 · Revision 1
- Added to Heist Feed
- Publisher date