sctp: disable BH before calling udp_tunnel_xmit_skb()
In the Linux kernel, the following vulnerability has been resolved: sctp: disable BH before calling udp_tunnel_xmit_skb() udp_tunnel_xmit_skb() / udp_tunnel6_xmit_skb() are expected to run with BH disabled. After commit 6f1a9140ecda ("add xmit recursion limit to tunnel xmit functions"), on the path: udp(6)_tunnel_xmit_skb() -> ip(6)tunnel_xmit() dev_xmit_recursion_inc()/dec() must stay balanced on the same CPU. Without local_bh_disable(), the context may move between CPUs, which can break the inc/dec pairing. This may lead to incorrect recursion level detection and cause packets to be dropped in ip(6)_tunnel_xmit() or __dev_queue_xmit(). Fix it by disabling BH around both IPv4 and IPv6 SCTP UDP xmit paths. In my testing, after enabling the SCTP over UDP: # ip net exec ha sysctl -w net.sctp.udp_port=9899 # ip net exec ha sysctl -w net.sctp.encap_port=9899 # ip net exec hb sysctl -w net.sctp.udp_port=9899 # ip net exec hb sysctl -w net.sctp.encap_port=9899 # ip net exec ha iperf3 -s - without this patch: # ip net exec hb iperf3 -c 192.168.0.1 --sctp [ 5] 0.00-10.00 sec 37.2 MBytes 31.2 Mbits/sec sender [ 5] 0.00-10.00 sec 37.1 MBytes 31.1 Mbits/sec receiver - with this patch: # ip net exec hb iperf3 -c 192.168.0.1 --sctp [ 5] 0.00-10.00 sec 3.14 GBytes 2.69 Gbits/sec sender [ 5] 0.00-10.00 sec 3.14 GBytes 2.69 Gbits/sec receiver
CVE-2026-53070
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-2026-53070
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": "046c052b475e7119b6a30e3483e2888fc606a2f8",
"lessThan": "7f0062c40781fe0a340965f5bb0816681982ff4c",
"versionType": "git"
},
{
"status": "affected",
"version": "046c052b475e7119b6a30e3483e2888fc606a2f8",
"lessThan": "be3bfcb34bda04f6a350710db471d4133f950f2c",
"versionType": "git"
},
{
"status": "affected",
"version": "046c052b475e7119b6a30e3483e2888fc606a2f8",
"lessThan": "0de7db2eb27e82b983157016fa604b1ba664ae5f",
"versionType": "git"
},
{
"status": "affected",
"version": "046c052b475e7119b6a30e3483e2888fc606a2f8",
"lessThan": "790093245e35040c2adb15f48970020425aa3f47",
"versionType": "git"
},
{
"status": "affected",
"version": "046c052b475e7119b6a30e3483e2888fc606a2f8",
"lessThan": "2cd7e6971fc2787408ceef17906ea152791448cf",
"versionType": "git"
}
],
"programFiles": [
"net/sctp/ipv6.c",
"net/sctp/protocol.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.11"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.11",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.95",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.37",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.10",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/sctp/ipv6.c",
"net/sctp/protocol.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-53070
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #46359 · Revision 1
- Added to Heist Feed
- Publisher date