CVE-2024-35900

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_tables: reject new basechain after table flag update

When dormant flag is toggled, hooks are disabled in the commit phase by

iterating over current chains in table (existing and new).

The following configuration allows for an inconsistent state:

add table x

add chain x y { type filter hook input priority 0; }

add table x { flags dormant; }

add chain x w { type filter hook input priority 1; }

which triggers the following warning when trying to unregister chain w

which is already unregistered.

[ 127.322252] WARNING: CPU: 7 PID: 1211 at net/netfilter/core.c:50 1 __nf_unregister_net_hook+0x21a/0x260

[...]

[ 127.322519] Call Trace:

[ 127.322521] <TASK>

[ 127.322524] ? __warn+0x9f/0x1a0

[ 127.322531] ? __nf_unregister_net_hook+0x21a/0x260

[ 127.322537] ? report_bug+0x1b1/0x1e0

[ 127.322545] ? handle_bug+0x3c/0x70

[ 12

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References