Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
netfilter: xt_nat: reject unsupported target families
xt_nat SNAT and DNAT target handlers assume IP-family conntrack state is present and can dereference a NULL pointer when instantiated from an unsupported family through nft_compat. A bridge-family compat rule can therefore trigger a NULL-dereference in nf_nat_setup_info().
Reject non-IP families in xt_nat_checkentry() so unsupported targets cannot be installed. Keep NFPROTO_INET allowed for valid inet NAT compat users and leave the runtime fast path unchanged.
[ The crash was fixed via 9dbba7e694ec (“netfilter: nft_compat: ebtables emulation must reject non-bridge targets”), so this patch is no longer critical. Nevertheless, NAT is only relevant for ipv4/ipv6, so this extra family check is a good idea in any case. ]
Details
- Affected product:
- Debian 10 ELS , Debian 11 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.10.259 (+4 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Amazon Linux 2023 | Planned | — |
| Oracle Linux 9 UEK 7 | Planned | — |