netfilter: nft_fib: reject fib expression on the netdev egress hook
A fib expression in a netdev egress base chain dereferences nft_in(pkt),
NULL on the transmit path, causing a NULL pointer dereference at eval.
nft_fib_validate() masks the hook with NF_INET_* values, but netdev hook
numbers are a separate enum that aliases them (NF_NETDEV_EGRESS ==
NF_INET_LOCAL_IN), so an egress chain passes validation and then faults.
Add nft_fib_netdev_validate() that limits each result/flag to the netdev
hook where the device it reads exists: the input-device cases (OIF,
OIFNAME, ADDRTYPE with F_IIF) to ingress, the output-device case (ADDRTYPE
with F_OIF) to egress, ADDRTYPE with no device flag to both. Also restrict
nft_fib_validate() to NFPROTO_IPV4/IPV6/INET so its NF_INET_* masks are
not applied to another family's hooks.
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
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| Linux | Linux | affected |
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No data.
No data.
No data available yet.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Sat, 15 Aug 2026 10:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-476 |
Sat, 15 Aug 2026 06:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_fib: reject fib expression on the netdev egress hook A fib expression in a netdev egress base chain dereferences nft_in(pkt), NULL on the transmit path, causing a NULL pointer dereference at eval. nft_fib_validate() masks the hook with NF_INET_* values, but netdev hook numbers are a separate enum that aliases them (NF_NETDEV_EGRESS == NF_INET_LOCAL_IN), so an egress chain passes validation and then faults. Add nft_fib_netdev_validate() that limits each result/flag to the netdev hook where the device it reads exists: the input-device cases (OIF, OIFNAME, ADDRTYPE with F_IIF) to ingress, the output-device case (ADDRTYPE with F_OIF) to egress, ADDRTYPE with no device flag to both. Also restrict nft_fib_validate() to NFPROTO_IPV4/IPV6/INET so its NF_INET_* masks are not applied to another family's hooks. | |
| Title | netfilter: nft_fib: reject fib expression on the netdev egress hook | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-15T05:54:42.239Z
Reserved: 2026-08-09T03:40:39.915Z
Link: CVE-2026-72254
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-08-15T06:21:52.910
Modified: 2026-08-15T06:21:52.910
Link: CVE-2026-72254
Redhat
No data.
OpenCVE Enrichment
Updated: 2026-08-15T10:15:03Z
-
CWE-476
NULL Pointer Dereference