CVE-2026-52998

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> netfilter: nfnetlink_osf: fix potential NULL dereference in ttl check<br /> <br /> The nf_osf_ttl() function accessed skb-&gt;dev to perform a local interface<br /> address lookup without verifying that the device pointer was valid.<br /> <br /> Additionally, the implementation utilized an in_dev_for_each_ifa_rcu<br /> loop to match the packet source address against local interface<br /> addresses. It assumed that packets from the same subnet should not see a<br /> decrement on the initial TTL. A packet might appear it is from the same<br /> subnet but it actually isn&amp;#39;t especially in modern environments with<br /> containers and virtual switching.<br /> <br /> Remove the device dereference and interface loop. Replace the logic with<br /> a switch statement that evaluates the TTL according to the ttl_check.