netfilter: revalidate bridge ports
ebt_redirect_tg() dereferences br_port_get_rcu() return without a
NULL check, causing a kernel panic when the bridge port has been
removed between the original hook invocation and an NFQUEUE
reinject.
A mere NULL check isn't sufficient, however. As sashiko review
points out userspace can not only remove the port from the bridge,
it could also place the device in a different virtual device, e.g.
macvlan.
If this happens, we must drop the packet, there is no way for us to
reinject it into the bridge path.
Switch to _upper API, we don't need the bridge port structure.
Also, this fix keeps another bug intact:
Both nfnetlink_log and nfnetlink_queue use CONFIG_BRIDGE_NETFILTER
too aggressive, which prevents certain logging features when queueing
in bridge family: NETFILTER_FAMILY_BRIDGE can be enabled while the old
CONFIG_BRIDGE_NETFILTER cruft is off.
Fixes tag is a common ancestor, this was always broken.
| Source | ID | Title |
|---|---|---|
Ubuntu USN |
USN-8726-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8727-1 | Linux kernel (OEM) vulnerabilities |
Ubuntu USN |
USN-8728-1 | Linux kernel (GCP) vulnerabilities |
Ubuntu USN |
USN-8760-1 | Linux kernel (NVIDIA) vulnerabilities |
Ubuntu USN |
USN-8726-2 | Linux kernel (Raspberry Pi) vulnerabilities |
Ubuntu USN |
USN-8726-3 | Linux kernel (IBM) vulnerabilities |
Ubuntu USN |
USN-8800-1 | Linux kernel (NVIDIA BaseOS) vulnerabilities |
Ubuntu USN |
USN-8760-2 | Linux kernel (NVIDIA) vulnerabilities |
Ubuntu USN |
USN-8726-4 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8728-2 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-8728-3 | Linux kernel (Oracle) vulnerabilities |
Ubuntu USN |
USN-8903-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8904-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-8905-1 | Linux kernel (GCP) vulnerabilities |
Ubuntu USN |
USN-8906-1 | Linux kernel (IBM) vulnerabilities |
Ubuntu USN |
USN-8903-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8905-2 | Linux kernel (GCP) vulnerabilities |
Ubuntu USN |
USN-9002-1 | Linux kernel (NVIDIA Tegra) vulnerabilities |
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Sat, 07 Nov 2026 07:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Fri, 30 Oct 2026 12:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Wed, 21 Oct 2026 13:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Fri, 26 Jun 2026 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Thu, 25 Jun 2026 11:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-476 |
Thu, 25 Jun 2026 09:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: netfilter: revalidate bridge ports ebt_redirect_tg() dereferences br_port_get_rcu() return without a NULL check, causing a kernel panic when the bridge port has been removed between the original hook invocation and an NFQUEUE reinject. A mere NULL check isn't sufficient, however. As sashiko review points out userspace can not only remove the port from the bridge, it could also place the device in a different virtual device, e.g. macvlan. If this happens, we must drop the packet, there is no way for us to reinject it into the bridge path. Switch to _upper API, we don't need the bridge port structure. Also, this fix keeps another bug intact: Both nfnetlink_log and nfnetlink_queue use CONFIG_BRIDGE_NETFILTER too aggressive, which prevents certain logging features when queueing in bridge family: NETFILTER_FAMILY_BRIDGE can be enabled while the old CONFIG_BRIDGE_NETFILTER cruft is off. Fixes tag is a common ancestor, this was always broken. | |
| Title | netfilter: revalidate bridge ports | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-11-06T16:24:07.914Z
Reserved: 2026-06-09T07:44:35.392Z
Link: CVE-2026-53220
Updated: 2026-11-06T16:22:40.949Z
Status : Modified
Published: 2026-06-25T09:16:39.743
Modified: 2026-11-06T17:18:14.810
Link: CVE-2026-53220
OpenCVE Enrichment
Updated: 2026-06-26T04:45:06Z
Ubuntu USN