CVE-2026-53389

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> net/tcp-ao: fix use-after-free of key in del_async path<br /> <br /> In tcp_ao_delete_key(), the del_async path skips the current_key<br /> and rnext_key validity checks present in the synchronous path,<br /> assuming these pointers are always NULL on LISTEN sockets. However,<br /> if a key was added with set_current=1/set_rnext=1 while the socket<br /> was in CLOSE state, current_key and rnext_key will be non-NULL<br /> after listen() transitions the socket to LISTEN.<br /> <br /> When such a key is deleted with del_async=1, hlist_del_rcu() and<br /> call_rcu() free the key without clearing the dangling pointers.<br /> After the RCU grace period, getsockopt(TCP_AO_INFO) dereferences<br /> current_key-&gt;sndid and rnext_key-&gt;rcvid from freed slab memory.<br /> <br /> Clear current_key and rnext_key in the del_async path when they<br /> reference the key being deleted.