Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: Avoid nf_ct_helper_hash uses after free If nf_conntrack_init_start() fails (for example due to a register_nf_conntrack_bpf() failure), the nf_conntrack_helper_fini() clean-up path frees the nf_ct_helper_hash map. When built with NF_CONNTRACK=y, further netfilter modules (e.g: netfilter_conntrack_ftp) can still be loaded and call nf_conntrack_helpers_register(), independently of whether nf_conntrack initialized correctly. This accesses the nf_ct_helper_hash dangling pointer and causes a uaf, possibly leading to random memory corruption. This patch guards nf_conntrack_helper_register() from accessing a freed or uninitialized nf_ct_helper_hash pointer and fixes possible uses-after-free when loading a conntrack module.
Affected products
linux: linux kernel
References8
- git.kernel.org/stable/c/00716f25f9697d02a0d9bd622575c7c7321ba3d0 Patch
- git.kernel.org/stable/c/05561f822f27b9fa88fa5504ddec34bf38833034 Patch
- git.kernel.org/stable/c/4ee69c91cb8f9ca144bc0861969e5a1a3c6152a7 Patch
- git.kernel.org/stable/c/61c7a5256543ae7d24cd9d21853d514c8632e1e9 Patch
- git.kernel.org/stable/c/6eef7a2b933885a17679eb8ed0796ddf0ee5309b Patch
- git.kernel.org/stable/c/6f03ce2f1abcb9f9d0511e3659ca6eb60e39f566 Patch
- git.kernel.org/stable/c/8289d422f5e484efe4a565fe18e862ecd621c175 Patch
- git.kernel.org/stable/c/fce5cc7cbd4b92f979bf02c9ec5fb69aaeba92d7 Patch
Metrics
- CVSS 3.1
-
7.8
HIGH
Score source: NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 13 · as of 9 November 2026
- CWE
- CWE-416
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