In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack_sip: validate skb_dst() before accessing it
tc ingress and openvswitch do not guarantee routing information to be available. These subsystems use the conntrack helper infrastructure, and the SIP helper relies on the skb_dst() to be present if sip_external_media is set to 1 (which is disabled by default as a module parameter).
This effectively disables the sip_external_media toggle for these subsystems without resulting in a crash.
References
- https://git.kernel.org/stable/c/09755dc62b026076b1d47f83489eb0547c8135e0
- https://git.kernel.org/stable/c/b843a96252f672332837ea2ecb7c8db0acf68e20
- https://git.kernel.org/stable/c/c199ed687c00841daf60e9d131976958583a8c09
- https://git.kernel.org/stable/c/e5e24a365a5e024efef63cc49abb345fbd4852c5
- https://git.kernel.org/stable/c/e64a48c50a1ff565a98c6a98d82b5b942868e76e